Absoluut benodigd is een Statief aangezien HDR met meerdere foto’s uit de hand bijna niet zonder beweging te doen is. Indien een statief geen optie is, is een IS (Image Stabilizer) bijna noodzakelijk (ik zelf gebruik sinds kort een 18-200mm IS).

Voor lastige situaties en nachtfotografie is een remote shutter of IR remote aan te bevelen (voor sluitertijden langer dan 30 sec. is dit zelfs noodzakelijk).

Naast de fotografie hardware is een behoorlijk bemeten PC of MAC nodig.

Photoshop heeft een aparte partitie nodig op het liefst een aparte HD als Scratch Disk. Op deze schijf mag geen OS staan en het liefst geen Page file. Hierdoor is een pc met minimaal 2 schijven en eigenlijk 3 partites benodigd.

2GB aan RAM is minimaal. XP en Vista ondersteunen standaard niet meer dan 3GB. Photoshop CS3 ondersteund 2GB. Vista 64 Bit kan wel met geheugen boven 3GB overweg. Photoshop CS4 is voornamelijk een snelheids verbetering ten opzichte van CS3 (helaas is dit voornamelijk een groot voordeel voor MAC gebruikers).

Gebruikte software:

PhotoShop CS3 (of CS4 natuurlijk). HET fotobewerkingsprogramma.

Adobe Lightroom 2 (of hoger). Lightroom is voor RAW bewerking en organisatie van fotomateriaal.

PhotoMatix 3 (of hoger), HDR Software.

LucisArt Photoshop plugin. Soort Blur Filter Plugin.

TopazAdjust Photoshop plugin. Filter software.

Noiseware Photoshop plugin. Ruisverminderingssoftware

Eventueel (nog niet getest) HDR MAX. Soortgelijk als Photomatix.

We zijn onderweg. Nu is kennis van de materie en veel tijd en oefening nodig voor het maken van goede HDR foto’s.

Als ik naar mijn eigen HDR materiaal kijk van vroeger (paar maanden geleden) en nu vraag ik me af waarom ik het oudere materiaal niet reeds ritueel verbrand heb. In ieder geval zien we progressie, en dat doet deugt.

Portrait image by Dan Stainsby

The first secret step must be completed before you even press the shutter on the camera. Your number one essential step for success is to first shoot your model against a white backdrop, sufficiently illuminated so that it is captured as white rather than gray. This important aspect of the initial image capture ensures that the resulting hair transplant is seamless and undetectable.

The post-production is the easy bit – simply apply the correct sequence of editing steps and the magic is all yours. This is not brain surgery but follow these simple steps and you will join the elite ranks of Photoshop gurus around the world. Celebrity status is just a few clicks away.

Step 1
The initial steps of this tutorial are concerned with creating a mask that can be used in the final montage. Start by dragging the background layer to the New Layer icon to duplicate it. Choose ‘Remove Color’ from the Adjust Color submenu found in the Enhance menu (Enhance > Adjust Color > Remove Color).

Drag this desaturated/monochrome layer to the New Layer icon in the Layers palette to duplicate it. Set the blend mode of this new layer (now on top of the layers stack) to ‘Overlay’ mode.

Step 2
From the Layer menu choose ‘Merge Down’ to create a single high-contrast monochrome layer. Select ‘Black’ as the foreground color and the ‘Brush tool’ from the Tools palette. Choose a large hard edged brush and 100% opacity from the Options bar and set the mode to ‘Overlay’ (also in the Options bar).

Painting in Overlay mode will preserve the white background and darken the rest of the pixels. Accuracy whilst painting in Overlay mode is not a concern when the background is white or is significantly lighter than the subject. Avoid going anywhere near the tips of the hair at this stage.

Step 3
Even the bright tones of the white shirt can be rendered black by repeatedly clicking the mouse whilst using a large brush in Overlay mode. Again it is important to avoid going anywhere near the hair.

Step 4
Darken the body of the hair near the scalp but avoid the locks of hair that have white background showing through. Painting these individual strands of hair will thicken the hair and may lead to subsequent halos appearing later in the montage process.

Performance Tip
Switch the blend mode of the brush in the Options bar to ‘Normal’ mode when painting away from the edge of the subject. This will ensure a speedy conclusion to the mask making process. The mask is now ready to use in the montage.

Note > If any of the background has been darkened in the process of creating a black and white mask switch the foreground color to ‘White’ and choose ‘Overlay’ in the Options bar. Paint to render any areas of gray background white. It is again important to avoid painting near the edges containing delicate hair detail.

Step 5
With the Remove Color layer selected add a Levels adjustment layer. Without making any adjustment simply select OK. This Levels adjustment layer has a layer mask that we can use to house the mask that we have created in the previous step.

Step 6
The next step relocates the mask you have just created into the layer mask of the adjustment layer. From the Select menu choose ‘All’ and from the Edit menu choose ‘Copy Merged’. Hold down the Alt key and click on the layer mask thumbnail in the Layers palette. The image window will momentarily appear white as you view the empty contents of the layer mask.

From the Edit menu choose ‘Paste’ to transfer the contents of the clipboard to this layer mask. Click on the layer below to select it and then click on the Visibility icon of this layer to switch it off. This mask layer serves no purpose now that it has been successfully transferred to the adjustment layer mask.

Step 7
The new background is placed on its own layer above the figure and mask layers. Drag the thumbnail of this new file into the image window of your project file from either the Photo Bin or the layer thumbnail in the Layers palette. Group this new background layer with the adjustment layer beneath (Layer > Group with Previous). Alternatively you can hold down the Alt key and click on the dividing line between the two layers to group them.

Step 8
Grouping the new background with the adjustment layer will mask the background in the region of the figure but the quality will not yet be acceptable. Setting the blend mode of the adjustment layer to ‘Multiply’ will bring back all of the fine detail in the hair. The background will be not darkened by applying the ‘Multiply’ blend mode as white is a neutral color. The subtle detail in the fine strands of hair will however be preserved in all their glory.

Step 9
The accuracy and quality of the edge of the mask will usually require some attention in order for the subject to achieve a seamless quality with the new background. Make a selection of all of the edges that do not include any hair detail using the Lasso tool with a small amount of feather set in the Options bar. With the adjustment layer mask selected choose the ‘Gaussian Blur filter’ (Filter > Blur > Gaussian Blur) and apply a 1- to 2-pixel Radius Blur to the mask.

Click OK and then from the Enhance menu choose a Levels adjustment from the Adjust lighting submenu. Move the central Gamma slider underneath the histogram to realign the edge of the mask with the subject edge (no dark or light halo should be visible).

Performance Tip
If the mask is too soft the edges can be sharpened by moving the black and white sliders in towards the central Gamma slider a little. Select OK when perfect alignment has been achieved.

Zoom in to 100% Actual pixels whilst working to accurately assess the quality of your mask.

Step 10
In most instances the hair is already looking pretty fabulous but to modify and perfect the hair even further you will need to inverse the selection (Select > Inverse). Choose ‘Levels’ once again and move the central Gamma slider to the left to increase the density of the hair and eliminate any white halos that may be present. Moving the White slider to the left a little may help the process of achieving a perfect blend between subject and background. Select OK and choose ‘Deselect’ from the Select menu.

Performance Tip
Any localized refinement of the mask can be achieved manually by painting with a small soft edged brush directly into the layer mask. Paint with white at a reduced opacity (10-20%) to remove any fine halos present in localized areas. Several brush strokes will slowly erase the halo from the image.

Step 11
The true test of an accurate mask for a subject that was photographed against a white background is when you place the subject against a very dark background. Grouping a Levels adjustment layer with the new background layer can darken the background image used in this project.

Hold down the Alt key when you select a Levels adjustment layer from the Layers palette. Click on the Group with Previous box in the New Layer dialog box and then select OK to open the Levels dialog box. Move the Gamma slider to the right in order to preview your subject against a darker background in the image window.

Result

Step 1

Start with the image of your choice, I chose this one.

Step 2

Go to your Channels Palette and figure out which of these channels has the highest contrast between the object you want to extract and the background. Usually it’s the blue channel. Make a copy of that layer and make sure the layer is not hidden.

Step 3

Press CTRL+L to open up the Levels Window and drag the controllers to raise the contrast between background and the object which shall be extracted. Be careful, don’t overdo it. If the contrast is too high, we won’t be able to extract the smaller objects.

Step 4

Now use the Lasso Tool (M) to trace around remaining bright parts of the object you want to extract. In my picture for example, I made a selection of the model’s face.

Step 5

Fill the selection with black.

Step 6

CTRL+Click the channel in your Channels Palette to make a selection. Click on the main RGB Channel and now you can copy&paste the selection into a new file.

Final Image

Now you can start using your object for any kind of design project you want. This is how it looks when put on a simple white background:

Result

In this Saturday morning post, I explain HDR photography with the help of some articles. This post includes step by step ways to create your own HDR images. Be advised that they can be quite hard for beginners to get interesting results. But where there is a will, there is a way! And by experimenting, you will get some good pictures. Also, remember that to see the end result, you have to get through some initial steps.
I have received some questions about certain photographs, so I’ve decided to include three articles that explains HDR photography in detail. I had added this to the comments, but I felt this deserved to be included in a post by its own. I have found a few different articles to explain this to everyone. The first one dwelves in the theory behind. The second one is an easy way to to HDR and the third one goes in to more detail on the process of HDR photography. The source of the first article is from cybergrain. The second article is from HDR 101. And the third is from Cambridgeincolour.This post also include step by step ways to create your own HDR images.

If you want anymore information, research the sites that I have mentioned or ask questions in the HDR Pool on flickr.

This is by no means the only pool on flickr for this type of photography. Check out here for more groups.

To begin using HDR photography, you need a few simple things.

1. A digital camera, preferably a DSLR but a good point and shoot will do the job. Remember, you need to be able to change the shutter speed manually. The focus can stay auto but if you can set it on manual do so
2. A tripod; to function correctly, HDR needs to take different pictures of the same scene. If you do not want any motion flow, take pictures of stationary objects.
3. Latest edition of Photoshop
4. Photomatix, available free here through their new beta release for Windows. A Mac version is also available on their website.
5. For simple step by step instructions, scroll down to the second article and follow the steps.

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The following article is by Jon Meyer from one of his articles on HDR Photography. You can find the source article here. Due to the interest, he has updated his article as of Sunday, the 16th of July. I have made the changes accordingly. Thanks Jon Meyer!

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The Future of Digital Imaging – High Dynamic Range Photography

Introduction

Today’s digital cameras match or slightly exceed the performance of silver halide film. Computer graphics has achieved the goal of photorealism. Now the goal is to go beyond simply matching paper and silver halide – to create display technologies which can present any visual stimuli our eyes are capable of seeing.

One area of rapid development is in dynamic range. A new crop of technologies using High Dynamic Range imaging (HDR or HDRI) aim to extend the dynamic range of digital imaging technologies way beyond traditional media.

In this article, I’ll look at recent advances in the field of high dynamic range imaging. I will cover the basic concepts of dynamic range, and talk about new HDR technologies.

The Problem

Here’s the problem in a nutshell:

• Real-world scenes contain light ranges that exceed a 50,000:1 dynamic range.
• For over a thousand years, media has been limited to around a 300:1 dynamic range.
• So you have a mapping issue: how do you represent light values in a scene using a much more limited set of light values for a particular media?

If you are not careful, you end up with results like this:

You can see the chair but nothing out of the window.

Old Solutions

Master painters were very clever about mapping scene intensities to canvas. They used a large number of tricks. Look at El Greco’s La Agoria en el Jardin from 1590:

El Greco used saturated colors of opposing hues to increase the apparent dynamic range of the scene. He also painted black or white lines around the edges of contours. Our eyes determine contrast locally, so increasing the contrast at local edges increases the overall perceived contrast of the scene.

(Generally, the phrase “dynamic range” in imaging refers to the measured ratio between high and low extremes in a set of intensity values. The word “contrast” is often used interchangeably with dynamic range, though I prefer to use “contrast” to refer to the perceived contrast of a scene, which may be different from the measured dynamic range. For example, El Greco’s edge contours increase perceived contrast but don’t change the actual dynamic range of canvas).

Here is an example from Monet. The red sun in his famous Impressions at Sunrise really leaps off the canvas (maybe not on your web browser!). The sun is actually the same brightness value as the surrounding clouds. However, since the sun is a saturated red placed over a saturated blue cloud, it creates a color vibration, and the sun looks much brighter than it is:

Check out webexhibits way-cool Flash illustration of this.

Dynamic Range in Photography

Photography involves a capture device (the camera), a storage medium (e.g. film), and a display or output device (e.g. paper).

The dynamic range of each stage (capture, storage and output) plays a crucial role in the quality of the results. In general, technologies with greater dynamic range produce more realistic results. But photography is a compound process, and the dynamic range of each stage must be considered. When the dynamic range of the source scene is too great for any one stage of the process, something must be sacrified: you must either give up detail in the shadows or the highlights. Photographers have to know and work withing the limitations of their camera, storage and output devices.

W. Eugene Smith spent five days in the darkroom until he came up with a print of Albert Schweitzer that he was happy with:

Smith was dealing with the issue that silver halide negatives have a greater dynamic range than photographic paper – so he had to “dodge and burn” different areas of the image to get a result where both the lamp and sitter are visible.

Perhaps the greatest master of dynamic range in photography was Ansel Adams. He was the first to systematically measure the sensitivity range of all of the equipment he used. His “zone system” let him predict precisely what details he could capture on film and paper, so he could make decisions before pressing the shutter:

Color Photography

Color negative films have less dynamic range (or “latitude”) than black and white films. My understanding is that the multiple layers and dies in color film result in reduced sensitivity. The first color films had very poor latitude, so film manufacturers added more layers – each color layer was split in two, a high-sensitivity and a low-sensitivity layer, using different crystal formations:

(I’m not an expert, but maybe color positive film doesn’t use this trick, hence the difference in latitude between positive and negative film?)

One way to get really great dynamic range with color film photography is to use black-and-white film together with color filters. You have to take three exposures on separate sheets of black and white film: one with a red filter, one with a green, and one with a blue – and then composite the three images together. If you use glass plate negatives, you end up with images that have incredible colors and resolution. See below:

The most amazing thing about this image is that it was taken in around 1915 by Prokudin Gorskii. While it is true that this image was digitally enhanced in Photoshop, in my own experiments with a 4×5 and red/green/blue filters I achieved an extended non-kodachrome tonal scale.

The Next Horizon: Digital HDR

Over the next decade, the imaging industry will inevitably transition to high dynamic range (HDR) imaging, creating devices that provide a latitude range far greater than traditional silver halide film. This change will affect all aspects of image making. Each of the systems in the image workflow will be modified, including capture, storage, editing and output.

Let’s look at each of these workflow stages in turn.

Capture

Today’s cameras have ample resolution. So the next area of product differentiation for camera manufacturers will be the quality of the pixels, rather than the number of pixels. This shift is starting to happen already.

For example, Fuji’s SuperCCD S3 Pro camera has a chip with high and low sensitivity sensors per pixel location to increase dynamic range (the same trick as used in color film to achieve broader latitude).

Although the resulting chip has lower overall resolution, it captures greater dynamic range. This tradeoff of resolution for dynamic range is the beginning of an important trend.

A second alternative is to merge multiple images to increase dynamic range. Paul Debevec at SIGGRAPH 97 showed how to take multiple photographs at different exposures and merge them together to create a single high-dynamic range image. This technique is now incorporated in products such as Photogenics and Photoshop. For now, the technique works best if the camera is mounted on a tripod. But researchers have already built HDR image “stitchers” which merge multiple images and automatically account for camera motion between snaps.

For most consumers, “HDR” will simply mean that the camera records more details in shadows and in highlights. Just as RAW images extended the detail held in digital images, HDR will further increase the available tonal range.

Consumers will benefit from the true point-and-shoot ability that broader latitude offers, because HDR cameras will produce usable images from a much wider range of lighting situations.

Eventually point-and-shoot cameras will lose their built-in flash. Anyone who uses a camera with a cheap flash soon learns that the pictures generally look better if you turn the flash off. Sensors are becoming more sensitive, cameras are getting smaller, and light metering is getting smarter. Add three or four stops of dynamic range, and the flash becomes a creative ad-on rather than a requirement.

Professional photographers will also benefit from HDR. With HDR technologies, photographers can really push the creative envelope, exploring the extremes of high-key and low-key effects.

Professional cameras will offer a multitude of HDR image-taking modes. For example, they will automatically blend multiple images taken with different exposures, with and without flash, possibly using multiple light sources, to produce a single and extremely maliable master image.

Storage

All image file formats have range limitations. Formats such as JPEG and GIF provide eight bits per color channel (often referred to as 24 bit color). Using 8 bits, you can represent 256 different intensities per channel. Most 8 bit formats use a “perceptual” mapping, meaning that they use a gamma (exponential) curve rather than a linear map of intensities. See Human vision and tonal levels or the venerable Gamma FAQ for an explanation of this. While JPEG and GIF are great for moderate dynamic range images, banding becomes apparent if you edit the image extensively, and the formats cannot store high-dynamic-range scenes.

Newer formats including JPEG2000, RAW and PNG offer up to 16 bits per color channel, which is plenty for most purposes. However, there is no support for “underage” or “overage” – these image formats state that “0? should be mapped to the darkest black of the display, and “65536? (or the equivalent) should be mapped to the whitest white. If you want to represent images that contain brightnesses beyond what your monitor can currently display (e.g. as produced by HDRShop), you need to look elsewhere.

The most exciting HDR image format today is OpenEXR, developed by Industrial Light & Magic.

I say this partly because their documentation includes photos from Star Wars (see above). But it also supports both 16-bit and 32-bit float representations, lossy and lossless codecs, and has a great definition for underage and overage.

Other examples of High Dynamic Range formats include SGI’s TIFF LogLuv format, Floating Point TIFF format, Radiance’s RGBE format, and Portable Float Maps (PFMs).

HDR image formats are especially significant for archival and stock uses, since they store data with enough precision to record what we can see, rather than what our displays can show.

There are a range of proprietary formats that offer medium or high dynamic range. The various RAW formats support whatever dynamic range the underlying device associated with the RAW file uses. Personally, I am not a fan of RAW formats for long term image stoage, since they are too device and vendor specific. However, that’s a whole other debate.

I don’t yet know if OpenEXR will become a consumer standard, or if it will remain a file format used only by Hollywood. Microsoft, Apple, Adobe, Canon and others will no doubt have a big hand in shaping that decision.

Editing

Of all imaging tasks, editing is the one that demands the highest dynamic range. Editing operations need high precision to avoid aliasing artifacts such as banding and jaggies.

Audio professionals know this. Editing tools like ProTools already use 48 bits per sample internally, even though the common CD output format only supports 16. Why should we image makers accept anything less?

Recently, Adobe announced supports for 32-bit-per-channel HDR images in Photoshop CS2, a great step forward.

Idruna Software is another company doing interesting HDR software. I played with their PhotogenicsHDR when it first came out, but I found it a little hard to use. Perhaps the newest PocketPC version is different…

Photoshop users are familiar with the issues of low dynamic range today. With 8 bit channels, if you brighten an image, information is lost irretrievably: darkening the image after brightening does not restore the original appearance. Instead, all of the highlights appear flat and washed out. To avoid this problem, you must work in a carefully planned workflow.

With a true HDR tool, if you brighten an image and then darken it, you should see something very close to the original image. True HDR editing tools will enable image workers to follow a much more flexible and simplified workflow, using fewer adjustment layers, with fewer aliasing artifacts. I expect HDR software will lead to increases in productivity and greater expressiveness.

It will take the imaging software industry some time to retool and retrain. There are plenty of unsolved issues.

With HDR, for example, you run into the issue of representing brightness values present in the image but beyond what your current monitor can show. Do you clamp to the monitor’s gamut, show zembra stripes, map the colors some other way?

Another issue is how to create graphical user interfaces for HDR editing. Many designers are familiar with the RGB 0-255 color values, and can type in RGB color numbers directly using this system. e.g. 128,128,128 is a mid gray. But what happens when intensities go from 0 to several million? Where is mid gray? And how do you represent that in a graphical interface? If the tonal range goes from 0 to something close to the brightness of the sun, where is “white” on that scale? Do you mean monitor white, paper white, 3200k white, 5600k white …?

A third unsolved issue is image size: If each channel of an image is 32 instead of 8 bits, the image becomes four times larger. Switching to HDR therefore makes a 100mb image take up 400mb. Not surprisingly, editing operations take about four times longer. Software will need to become smarter about scheduling work. Live Picture, an early image compositing tool, did a good job of this, but is no longer available. I expect to see a revival of these techniques as people grapple with 10GB images.

Tone Mapping

Most LCD/CRT displays (and of course printed paper) have low dynamic range.

So if you want to output an HDR image on paper or on a display, you must somehow convert the wide intensity range in the image to the lower range supported by the display. This process is called tone mapping.

One old tone-mapping method is the manual dodge-and-burn technique familiar to photographers – where you manually select different tonal ranges for different regions of the image, using a dodging or a burning tool. HDR software will of course support manual dodge and burn.

Another solution is to use an automated tone mapping filter to reduce the dynamic range of an HDR image. There are already several filters to choose from.

The left image above shows what you get if you display Paul Debevec’s HDR photo of Stanford Memorial Church using a very basic tone mapping technique (simply clamping to the nearest available color on the monitor). Some areas of the image are “blown out”, and the shadow areas are muddy and lack detail.

The right image show’s Fattal, Lischinkski, and Werman’s tone mapping algorithm, which uses a more sophisticated adaptive approach – you see more details in the shadows and the highlights (look at the stained glass windows), though the image also has a somewhat “flat” or “computerish” quality.

Tone mapping is a hot area of research in computer graphics. As with HDR file formats, there is currently no clear winner. Several techniques are listed in the resource section. I expect the major companies to each champion their own tone-mapping technologies in service bureaus and print finishing.

Output

Over the past decade, display companies have steadily improved the dynamic range of LCD and DLP displays. Today many digital displays have a 2000:1 dynamic range, unheard of ten years ago. This trend of increasing dynamic range will continue.

A few displays available today indicate where the market is going. The most astonishing is the BrightSide HDR display with a claimed contrast ratio of 60,000:1, good enough to reproduce the effect of a sunlit scene. They achieve this using high-power white LEDs.

The only bad thing about the BrightSide display is that once you look at it for a few minutes you just assume that this is how images are supposed to look – it is such a transparently great technology that until you see a normal image on a normal display you don’t really think of the HDR display as that exciting. The display is still in the very-expensive bracket, but this will change quickly.

Of course, HDR displays work best if you have lots of HDR images. I anticipate a huge market for stock HDR imagery. See the Flickr HDR group for starters.

Applications

Today, the main users of HDR imaging devices are specialized professionals working in the film, animation and VR industries. Some applications are listed below (see the Resources page for links).

Film – Tools such as HDRShop by Paul Debevec enable you to convert a series of photographs into a light probe – a special image that represents the lighting environment in a room. You can then use the light probe to light virtual objects, so that the virtual objects actually appear to be lit by the light from the room. This technique is especially useful for compositing computer graphic objects into images of real scenes. Hollywood films use light maps extensively to blend CGI into a scene.

Panoramas – Another use for HDR is in panoramic images. Panoramas often have a wide dynamic range, e.g. one part of the panorama may contain the sun, another part may be in deep shadow. Online web panoramas constructed from HDR images look much better than non-HDR equivalents.

Games – A third use for HDR is in computer games. Recent computer graphics cards support HDR texture maps. With HDR texture maps, you can render objects using light probes, in real time, yielding much more dynamic and interesting lighting effects. “High Dynamic Range Lighting Effects” are now all the range in high-end games.

As more consumer-oriented HDR products arrive, I believe the largest application of HDR will be in consumer photography, though the term HDR is unlikely to be seen – instead you will see branding terminology, e.g. companies will make up words like “DynaChrome”, “MaxBright”, “SuperColor” etc.

Do we really need HDR?

I recently read this comment from Sam Berry:

… the whole article has no mention of the fact that the reason most controlled lighting is almost always done to ratio of less than 8:1 even with neg film /modern digital capable of much more is because that’s what looks good. HDR technology now means you can reproduce your harsh midday sunlit scene perfectly, and it will look identically awful compared to the original.

The debate boils down to this: Does an image with a 300:1 dynamic range look good because it represents a physical sweetspot — something to do with our perceptual system that works well at that ratio? Or is it that all we’ve had access to for hundreds of years are reflective images with a roughly 300:1 dynamic range, so we are accustomed to that?

I had a similar question in my mind before seeing the BrightSide HDR display. Now, after looking at a HDR image on a 50,000:1 HDR display, I am no longer concerned about over-brightness, 50,000:1 is still way less than the brightness of looking directly at the sun. It wasn’t blinding. It isn’t a question of harsh. Images simply looks better when they look more real.

In the coming decade, HDR digital imaging technology will arrive, and change how we take, manipulate, store, use and display images forever.

* * * * *

This next article explains how exactly to do an HDR image with digital technology. It is written by Fabo from hdr101. His site contains further HDR resources.

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HDR Tutorial (Photomatix) (English)

This is a basic, standard, step by step tutorial of how to make an HDR Image.(Note: this tutorial is based on building an HDR image from 7 differents shots. My camara doesn’t shoot RAW. More on building an HDR image from a single RAW file, soon!)

The materials for this process are as follows:

Hardware:

* Digital Camera (Obvius, but hey you never know )

* Tripod

Software:

* Photomatix (used for Generating HDR and Tone Mapping)

* Photoshop CS2. (But for this tutorial any version of Photoshop will do. We’ll be using it for retouching only)

Ok, let’s get going!

Taking the pictures:

Put your camera in the tripod. Place it firmly because you’ll have to touch the camera to change the speed and this can make you move it, and then, well you wont be able to get the HDR you were hoping for.

After selecting the subject you wish to shoot, prepare everything as if you were only going to take one picture. Prepare it to your taste or what ever is you want to acomplish.

Set your primary exposure and speed. We are going to call this master setting 0. After this is complete and you have everything set up you are going to take let’s say 7 pictures:

3 pictures up from 0 and 3 pictures down.

Dude what do you mean?? Don’t panic is quite easy:

If the settings for picture 0 is: 1/125 and f/4.5

The settings for the remaining pictures are as follows:

* Picture +3: 1/250 f/4.5

* Picture +2: 1/200 f/4.5

* Picture +1: 1/160 f/4.5

* Picture 0: 1/125 f/4.5 (YOUR MASTER SETTING)

* Picture -1: 1/100 f/4.5

* Picture -2: 1/80 f/4.5

* Picture -3: 1/60 f/4.5

You’ve may noticed that the F/ stays the same. This is quite simple: if that value changes also will you Depth of Field which will cause you focus to change also.

Now that you have taken all your pictures is time to go and kick some Photomatix but!

Ok, so you got to your computer, opened up Photomatix, and oh well you have no idea what to do. No problem becouse this part of the process has litle pictures in it, so you wont have any excuse not to make HDR pictures!!

Photomatix:

Open Photomatix and look for the HDRI tab. Click on it. After you will see GENERATE HDR. Go ahead click some more.

When you do that something like this comes up:

Now you click on the BROWSE button and select the pictures you want:

After you you click the SELECT button a screen like this come along:

Ok. Now your pictures are selected and you click OK. Now you have to choices: to Align Input Images or not to let the software do it. I personally always let the software do it. Is up to you:

Now you’ll get this screen. Depending on you computer memory this may take a while, but not to long. I’ve notice that when one of the picture is to dark or to bright, in Auto Align, Photomatix has a hard time aligning the images. I usually cancel and deselect the image I think is causing the problem:

If everything is ok, this should come up:

After Photomatix is done, it shows you your new Generated HDR Image:

But you want it like does cool ones out there! Wait, there’s more: ToneMapping!

Now you go to the HDRI tab and select Tone Mapping. Here is where the fun begins!

The first thing you may notice is the difference in the picture. Here you have 7 important options:

• Luminosity
• Strength
• Color Saturation
• White Clip
• Black Clip
• Smoothing
• MicroContrast

I could go on and explain what all those sliders and buttons do, but we’ll do something better: You try!

Move them up, down, put some more here, take some less there. The idea is for you to experience it for yourself. Trust me, is really fun that way!

So after moving around the sliders i get to a point where i like the results:

I go click on OK, and we go back to the first screen but with the final version of the photo:

Now i want to take it to Photoshop for aditional retouching but first i have to save it. I preffer TIFF format:

Choose your name, location and format:

Now go open Photoshop, and open the TIFF you just saved:

Now go to the IMAGE tab, ADJUSTMENTS. Now you have to play and have fun with each and every other option in there. Try everything and if you do something you don’t like, don’t worry UNDO! (Also play with some filters, they can help to!)

After playing a litle bit, i got to this point which i like:

Now save it again in any format you like. I always save them on TIFF:

Voila! Your first HDR Image. Kind a cool, insn’t?

* * * * *

And the last one is by Sean T. McHugh from his photographic tutorials located on Cambrigdeincolour.

* * * * *

HIGH DYNAMIC RANGE PHOTOGRAPHY

High dynamic range (HDR) images enable photographers to record a greater range of tonal detail than a given camera could capture in a single photo. This opens up a whole new set of lighting possibilities which one might have previously avoided—for purely technical reasons. The new “merge to HDR” feature of Photoshop CS2 allows the photographer to combine a series of bracketed exposures into a single image which encompasses the tonal detail of the entire series. There is no free lunch however; trying to broaden the tonal range will inevitably come at the expense of decreased contrast in some tones. Learning to use the merge to HDR feature in Photoshop CS2 can help you make the most of your dynamic range under tricky lighting—while still balancing this trade-off with contrast.

MOTIVATION: THE DYNAMIC RANGE DILEMMA

As digital sensors attain progressively higher resolutions, and thereby successively smaller pixel sizes, the one quality of an image which does not benefit is its dynamic range. This is particularly apparent in compact cameras with resolutions near 8 megapixels, as these are more susceptible than ever to blow highlights or noisy shadow detail. Further, some scenes simply contain a greater brightness range than can be captured by current digital cameras– of any type.

The “bright side” is that nearly any camera can actually capture a vast dynamic range– just not in a single photo. By varying the shutter speed alone, most digital cameras can change how much light they let in by a factor of 50,000 or more. High dynamic range imaging attempts to utilize this characteristic by creating images composed of multiple exposures, which can far surpass the dynamic range of a single exposure.

WHEN TO USE HDR IMAGES

I would suggest only using HDR images when the scene’s brightness distribution can no longer be easily blended using a graduated neutral density (GND) filter. This is because GND filters extend dynamic range while still maintaining local contrast. Scenes which are ideally suited for GND filters are those with simple lighting geometries, such as the linear blend from dark to light encountered commonly in landscape photography (corresponding to the relatively dark land transitioning into bright sky).

In contrast, a scene whose brightness distribution is no longer easily blended using a GND filter is the doorway scene shown below.

Brightness Distribution	Underexposure	Overexposure

We note that the above scene contains roughly three tonal regions with abrupt transitions at their edges– therefore requiring a custom-made GND filter. If we were to look at this in person, we would be able to discern detail both inside and outside the doorway, because our eyes would adjust to changing brightness. The goal of HDR use in this article is to better approximate what we would see with our own eyes through the use of a technique called tonal mapping.

INNER WORKINGS OF AN HDR FILE

Photoshop creates an HDR file by using the EXIF information from each of your bracketed images to determine their shutter speed, aperture and ISO settings. It then uses this information to assess how much light came from each image region. Since this light may vary greatly in its intensity, Photoshop creates the HDR file using 32-bits to describe each color channel (as opposed to the usual 16 or 8-bits, as discussed in the tutorial on “Understanding Bit Depth“). The real benefit is that HDR files use these extra bits to create a relatively open-ended brightness scale, which can adjust to fit the needs of your image. The important distinction is that these extra bits are used differently than the extra bits in 16-bit images, which instead just define tones more precisely (see tutorials on the “RAW File Format” and “Posterization“). We refer to the usual 8 and 16-bit files as being low dynamic range (LDR) images, relatively speaking.

The 32-bit HDR file format describes a greater dynamic range by using its bits to specify floating point numbers, also referred to as exponential notation. A floating point number is represented by a fractional numerical value raised to some power of 10, such as 5.467×10³, as opposed to the usual 0-255 (for 8-bit) or 0-65535 (for 16-bit) integer color specifications. This way, an image file can specify a brightness of 4,300,000,000 simply as 4.3x10⁹, which would be too large even with 32-bit integers.

We see that the floating point notation certainly looks neater and more concise, but how does this help a computer? Why not just keep adding more bits to specify successively larger numbers, and therefore a larger dynamic range? Recall that for ordinary LDR files, far more bits are used to distinguish lighter tones than darker tones (from the tutorial on gamma correction, tonal levels and exposure – to be added). As a result, as more bits are added, an exponentially greater fraction of these bits are used to specify color more precisely, instead of extending dynamic range.

The more closely spaced bits for brighter values is a result of the fact that ordinary 8 and 16-bit JPEG files are gamma-encoded, which can actually help increase dynamic range for low-bit files; gamma-encoding just becomes more and more inefficient as the bit depth increases.

HDR files get around this LDR dilemma of diminishing returns by using floating point numbers which are proportional to the actual brightness values of the subject matter (gamma equals one, or linear). This ensures that bits are equally spaced throughout the dynamic range, and not just concentrated in the brighter tones– allowing for greater bit efficiency. Further, the use of floating point numbers ensure that all tones are recorded with the same relative precision, since the base (mantissa) in numbers such as 2.576×10³ and 8.924×10⁹ each have the same number of significant figures (four), even though the second number is more than a million times larger.

Note: just as how using high bit depth images do not necessarily mean your image contains more color, a high dynamic range file does not guarantee greater dynamic range unless this is also present in the actual subject matter.

All of these extra bits provided by the HDR format are great, and effectively allow for a nearly infinite brightness range to be described. The problem is that your computer display (or the final photographic print) can only show a fixed brightness scale. This tutorial therefore focuses on how to create and convert HDR files into an ordinary 8 or 16-bit image, which can be displayed on a monitor, or will look great as a photographic print. This process is also commonly referred to as tonal mapping.

IN-FIELD PREPARATION

Since creating a HDR image requires capturing a series of identically-positioned exposures, a sturdy tripod is essential. Photoshop has a feature which attempts to align the images when the camera may have moved between shots, however best results are achieved when this is not relied upon.

Make sure to take at least three exposures, although five or more is recommended for optimum accuracy. More exposures allow the HDR algorithm to better approximate how your camera translates light into digital values (a.k.a. the digital sensor’s response curve)– creating a more even tonal distribution. The doorway example is best-suited with several intermediate exposures, in addition to the two shown previously.

Reference	-1 Stops	-2 Stops	-3 Stops

It is essential that the darkest of these exposures includes no blown highlights in areas where you want to capture detail. The darkest exposure should show the darkest regions of the image with enough brightness that they are relatively noise-free and clearly visible. Each exposure should be separated by one to two stops, and these are ideally set by varying the shutter speed (as opposed to aperture or ISO speed). Recall that each “stop” refers to a doubling (+1 stop) or halving (-1 stop) of the light captured from an exposure.

We also note another disadvantage of HDR images: they require relatively static subject matter, due to the necessity of several separate exposures. Our previous ocean sunset example would therefore not be well-suited for the HDR technique, as the waves would have moved significantly between each exposure.

CREATING A 32-BIT HDR FILE IN PHOTOSHOP CS2

Here we use Adobe Photoshop CS2 to convert the sequence of exposures into a single image, which uses tonal mapping to approximate what we would see with our eye. Before tonal mapping can be performed, we first need to combine all exposures into a single 32-bit HDR file.

Open the HDR tool (File>Automate>Merge to HDR…), and load all photographs in the exposure sequence; for this example it would be the four images shown in the previous section. If your images were not taken on a stable tripod, this step may require checking “Attempt to Automatically Align Source Images” (which greatly increases processing time). After pressing OK, you will soon see a “Computing Camera Response Curves” message.

Once your computer has stopped processing, it will show a window with their combined histogram. Photoshop has estimated the white point, but this value often clips the highlights. You may wish to move the white point slider to the rightmost edge of the histogram peaks in order to see all highlight detail. This value is for preview purposes only and will require setting more precisely later. After pressing OK, this leaves you with a 32-bit HDR image, which can now be saved if required. Note how the image may still appear quite dark; only once it has been converted into a 16 or 8-bit image (using tonal mapping) will it begin to look more like the desired result.

At this stage, very few image processing functions can be applied to a 32-bit HDR file, so it is of little use other than for archival purposes. One function which is available is exposure adjustment (Image>Adjustments>Exposure). You may wish to try increasing the exposure to see any hidden shadow detail, or decreasing the exposure to see any hidden highlight detail.

USING HDR TONAL MAPPING IN PHOTOSHOP CS2

Here we use Adobe Photoshop CS2 to convert the 32-bit HDR image into a 16 or 8-bit LDR file using tonal mapping. This requires interpretive decisions about the type of tonal mapping, depending on the subject matter and brightness distribution within the photograph.

Convert into a regular 16-bit image (Image>Mode>16 Bits/Channel…) and you will see the HDR Conversion tool. The tonal mapping method can be chosen from one of four options, described below.

Exposure and Gamma	This method lets you manually adjust the exposure and gamma, which serve as the equivalent to brightness and contrast adjustment, respectively.
Highlight Compression	This method has no options and applies a custom tonal curve, which greatly reduces highlight contrast in order to brighten and restore contrast in the rest of the image.
Equalize Histogram	This method attempts to redistribute the HDR histogram into the contrast range of a normal 16 or 8-bit image. This uses a custom tonal curve which spreads out histogram peaks so that the histogram becomes more homogenous. It generally works best for image histograms which have several relatively narrow peaks with no pixels in between.
Local Adaptation	This is the most flexible method and probably the one which is of most use to photographers. Unlike the other three methods, this one changes how much it brightens or darkens regions on a per-pixel basis (similar to local contrast enhancement). This has the effect of tricking the eye into thinking that the image has more contrast, which is often critical in contrast-deprived HDR images. This method also allows changing the tonal curve to better suit the image.

Before using any of the above methods, one may first wish to set the black and white points on the image histogram sliders (see “Using Levels in Photoshop” for a background on this concept). Click on the double arrow next to “Toning Curve and Histogram” to show the image histogram and sliders.

The remainder of this tutorial focuses on settings related to the “local adaptation” method, as this is likely the most-used, and provides the greatest degree of flexibility.

CONCEPT: TONAL HIERARCHY & IMAGE CONTRAST

In contrast to the other three conversion methods, the local adaptation method does not necessarily retain the overall hierarchy of tones. It translates pixel intensities not just with a single tonal curve, but instead also based on the surrounding pixel values. This means that unlike using a tonal curve, tones on the histogram are not just stretched and compressed, but may instead cross positions. Visually, this would mean that some part of the subject matter which was initially darker than some other part could later acquire the same brightness or become lighter than that other part– if even by a small amount.

Underexposed Photo	Overexposed Photo	Final Composite that Violates Large-Scale Tonal Hierarchy

A clear example where global tonal hierarchy is not violated is the example used in the page on using a GND to extend dynamic range (although this is not how local adaptation works). In this example, even though the foreground sea foam and rock reflections are actually darker than the distant ocean surface, the final image renders the distant ocean as being darker. The key concept here is that over larger image regions our eyes adjust to changing brightness (such as looking up at a bright sky), while over smaller distances our eyes do not. Mimicking this characteristic of vision can be thought of as a goal of the local adaptive method– particularly for brightness distributions which are more complex than the simple vertical blend in the ocean sunset above.

An example of a more complex brightness distribution is shown below for three statue images. We refer to contrast over larger image distances as global contrast, whereas contrast changes over smaller image distances are termed local contrast. The local adaptation method attempts to maintain local contrast, while decreasing global contrast (similar to that performed with the ocean sunset example).
The above example illustrates visually how local and global contrast impact an image. Note how the large-scale (global) patches of light and dark are exaggerated for the case of high global contrast. Conversely, for the case of low global contrast the front of the statue’s face is virtually the same brightness as it’s side.

The original image looks fine since all tonal regions are clearly visible, and shown with sufficient contrast to give it a three-dimensional appearance. Now imagine that we started with the middle image, which would be an ideal candidate for HDR conversion. Tonal mapping using local adaptation would likely produce an image similar to the far right image (although perhaps not as exaggerated), since it retains local contrast while still decreasing global contrast (thereby retaining texture in the darkest and lightest regions).

HDR CONVERSION USING LOCAL ADAPTATION

The distance which distinguishes between local and global contrast is set using the radius value. Radius and threshold are similar to the settings for an unsharp mask used for local contrast enhancement. A high threshold improves local contrast, but also risks inducing halo artifacts, whereas too low of a radius can make the image appear washed out. For any given image, it is recommended to adjust each of these to see their effect, since their ideal combination varies depending on image content.

In addition to the radius and threshold values, images almost always require adjustments to the tonal curve. This technique is identical to that described in the Photoshop curves tutorial, where small and gradual changes in the curve’s slope are nearly always ideal. This curve is shown for our doorway example below, yielding the final result.

HDR images which have been converted into 8 or 16-bit often require touching up in order to improve their color accuracy. Subtle use of levels and saturation can drastically improve problem areas in the image. In general, regions which have increased in contrast (a large slope in the tonal curve) will exhibit an increase in color saturation, whereas the opposite occurs for a decrease in contrast. Changes in saturation may sometimes be desirable when brightening shadows, but in most other instances this should be avoided.

The main problem with the local adaptation method is that it cannot distinguish between incident and reflected light. As a result, it may unnecessarily darken naturally white textures and brighten darker ones. Be aware of this when choosing the radius and threshold settings so that this effect can be minimized.

TIP: USING HDR TO REDUCE SHADOW NOISE

Even if your scene does not require more dynamic range, your final photo may still improve from a side benefit: decreased shadow noise. Ever noticed how digital images always have more noise in the shadows than in brighter tones? This is because the image’s signal to noise ratio is higher where the image has collected more of a light signal. You can take advantage of this by combining a properly exposed image with one which has been overexposed. Photoshop always uses the most exposed image to represent a given tone—thereby collecting more light in the shadow detail (but without overexposing).

RECOMMENDATIONS

Keep in mind that HDR images are extremely new– particularly in the field of digital photography. Existing tools are therefore likely to improve significantly; there is currently, and may never be, an automated single-step process which converts all HDR images into those which look pleasing on screen, or in a print. Good HDR conversions therefore require significant work and experimentation in order to achieve realistic and pleasing final images.

Additionally, incorrectly converted or problematic HDR images may appear washed out after conversion. While re-investigating the conversion settings is recommended as the first corrective step, touch-up with local contrast enhancement may also yield a more pleasing result.

As with all new tools, be careful not to overdo their use. Use care when violating the image’s original tonal hierarchy; do not expect deep shadows to become nearly as light as a bright sky. In our doorway example, the sunlit building and sky are the brightest objects, and they stayed that way in our final image. Overdoing editing during HDR conversion easily can cause the image to lose its sense of realism. Furthermore, HDR should only be used when necessary; best results can always be achieved by having good lighting to begin with.

HDR-Style Results Using Layers in Photoshop
Learn how to achieve HDR results in Photoshop using bracketed exposures during the production process and then Photoshop layers afterwards.

How to Create Professional HDR Images
Here’s an excellent (and very popular) tutorial on creating high dynamic range (HDR) images; the author focuses on realism instead of going overboard with the application of HDR.

Photoshop HDR tutorial
This tutorial shows you how to create true HDR using bracketed exposure and Photoshop for post-production.

Using the HDR Feature in Photoshop CS2/CS3
This thorough tutorial walks you through the basic concept of HDR photography and how to use Photoshop to make your photographs pop.

How to Make Digital Photos Look like Lomo Photography
In this tutorial, you’ll learn how to apply the “lomography” effect to your digital photos.

Infrared Photo Effect in Photoshop
This tutorial shows you a way to simulate the infrared effect with photos taken using point-and-shoot cameras.

Exposure blending tutorial
Create an HDR photo by blending exposures with this Photoshop tutorial.

Your photos, 300-style!
Give photographs the sepia-toned 300 movie effect.

How to Use Photoshop’s Lens Blur Tool for Tilt-Shift Fakery
Tilt-shift lenses are expensive and not very versatile. Save some money by checking out this Photoshop tutorial on how to fake tilt-shift photography.

Tilt Shift Photoshop Tutorial: How to Make Fake Miniature Scenes
Here’s another method for faking tilt-shift photography.

The Tilt-Shift Miniature Fake Technique
This tutorial walks you through the basics of picking a subject for the tilt-shift effect and using Photoshop’s blur and gradient tools to fake it.

Vignette 2.0
Give your photos a natural-looking vignette effect by following along in this Photoshop tutorial.

Adding a Diffuse Glow to Your Images
Apply diffuse glow to your photographs to create a dreamy effect with this Photoshop tutorial.

Image Enhancement and Correction

Improving Landscape Photographs
Enhance your landscape images by reading through this Photoshop tutorial.

Using Masks to Improve Landscape Images
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Color Correction, by the Numbers
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Color Correction Using Levels and Eyedroppers
In this Photoshop tutorial, you’ll see another method of correcting colors by using the levels-adjustment feature and by sampling colors with the eyedropper tool.

Enhance Your Image with Selective Color Adjustments
This tutorial uses a “non-destructive” and selective method for enhancing colors in a photograph.

Black and White Is the Key to Better Color
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Understanding Local Contrast Enhancement
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Local Contrast Enhancement
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Sharpening Using an Unsharp Mask
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Sharpen Those Photos: Unsharp Mask
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Noise Reduction by Image Averaging
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Using the Photoshop Levels Tool
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Using the Photoshop Curves Tool
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Advanced Photo Sharpening
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Controlled Image Sharpening
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Digital Blending
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Gaussian Blur
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Lens Correction Filter in Photoshop CS2
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Photo Manipulation and Retouching

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Getting a Grip on the Vanishing Point Filter
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Colour to Black and White Using Channel Mixer
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Quick Fix for Cluttered Backgrounds
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Antiquing Digital Images in Photoshop
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Creating a Sunset Effect in Photoshop Tutorial
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Photo Retouching: Spotlight Effect
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Image Retouching: Advanced Skin Softening
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Nesting Smart Objects for Multi-Mask Effects in Photoshop
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Step 1

Open an image with a horizon that’s not level. Instead of having to guess the angle to fix this at, here’s a short method that is lot more effective. You can use this image and save it to the computer and open in Photoshop.

Step 2

Click-and-hold the Eyedropper tool to pull out the menu. Click on the Ruler tool.

Step 3

Click-and-drag the Ruler tool along the crooked horizon.

Step 4

Go to Image>Rotate Canvas>Arbitrary.

Step 5

The degree of angle will be set to change the ruler to being level. Press OK.

Step 6

Now we have some areas to crop out. Select the Crop tool.

Step 7

Finally, we have a level horizon. We did change the composition though because areas had to be cropped out, so weigh the pros and cons before adjusting a horizon.

This technique begins in the camera. Using a tripod, take two exposures of the same scene. Expose your first image to capture detail in the highlights. Expose your second image to capture shadow detail.

(Image 1 above contains the shadow detail, Image 2 below contains the highlight detail)

Note: Unlike most HDR processing methods, this technique works better when there is a large difference in light between shadow and highlight. For example, a sunrise or sunset shot would work better than a shot taken in overcast conditions.

Once back at your computer, upload your images making sure to label the images in the order they were taken.

Select two sequential exposures, one for highlights and one for shadows. Open them both in Adobe Camera RAW. (Note: CS3 Camera Raw is now an option for both TIFF and JPEG files). Select your shadows exposure and make adjustments that enhance the shadow details. Then select your highlights exposure and make adjustments that enhance your highlight details. Once you are happy with these adjustments save them and then open both images in Photoshop.

With both images open in Photoshop, hit the ‘F’ key to toggle through the screen modes until you are in Standard Screen Mode where you are able to see each image with a menu bar at the top.

Select the Move tool and click on one of the images. Then hold down the Shift key and click-and-drag that image into the other one so that the two are now part of the same document. By holding down the Shift key you are ensuring that both images will line up properly. However, since a perfect set of exposures is often hard to capture in the field, I often follow this step by using CS3s new Auto-Align Layers tool.

To take advantage of the Auto-Align tool, the first thing you will need to do is double-click on your background layer and make the background an editable layer. Now you have two editable layers.

Next, select both layers by holding down the Shift key and clicking on both. Then, go to the Edit menu and select Auto-Align Layers from the drop down menu. (Use the ‘Auto’ Projection option) Now you have two perfectly aligned exposures.

Again, select both layers in the Layers palette and drag them down to the New Layer icon. This will produce two copies of your active layers. Hide your two newly-created layers by clicking the Eye icon next to them in the Layers Pallete.

Next, blend the two layers together. Select the top layer, in this case the highlight detail, and select Blending Options from the Layers Style menu inside the Layers drop-down menu.

Inside the Blending Options menu, at the very bottom, you will see two sliders underneath a “blend if” dialog.

Move the menu box to the side, making sure you can see your image clearly. Then holding down the Alt key (Option on a Mac) grab the white arrow at the end of the top slider. Holding down the Alt key will split that white arrow in half.

Move that half of the arrow toward the black end of the slider. You will notice your image begin to blend.

Move the arrow until you feel the correct amount of blending has occurred. Keep in mind the image will appear very flat. Don’t worry, that will be corrected later.

Now that you have partially blended the original layers, move back to your unblended layer copies.

Make both visible again by clicking to the left of the thumbnail and bringing back the Eye icon.

Next, make sure these layers are above your masked layers.

One at a time, select the layer, hold the Alt key (Option on a Mac) and click the Add Layer Mask icon. Holding down the Alt key fills the layer masks with black. Add a black layer mask to both of the unblended layer copies. You have just hidden these layers again. However, this time you are able to selectively bring them back.

Selectively go through your image adding back pieces of the original exposure where you deem necessary. (I like to use a very low opacity brush, 40 or 50 percent usually works fine.)

Make sure to use a large, soft-edged brush to help prevent obvious brush lines in your image. Notice that by gently adding pieces of the original exposure you have already helped add contrast to the scene.

Now we are going to create what I like to call a ‘working layer’. Once you have blended the layers to your liking, select all the layers using the Shift key and make a copy of each. Select these newly-created copies and use the Fly Out menu at the upper right of your Menu Pallet to select Merge Layers. You have just created a working layer. It is from this layer that dust removal and/or lens corrections are made.

Now is the time that you add contrast to your final image. Select a soft-edged brush and go into the Quick Mask mode by pressing ‘Q’. Select portions of the image where you want to add contrast by painting on the image. The areas will show uup red in Quick mask mode. When you have selected the areas that need a boost in contrast, hit ‘Q’ again and go back to regular view. You will see all of the areas that you painted in red are now selected.

In most cases I find a simple curves adjustment layer is all that is necessary. However, this is a good place to experiment with levels as well. Apply your adjustment layer and tweak the settings to your liking.

Finish things up with a global curves and levels adjustment to your working layer.

Voila! You have yourself a natural High Dynamic Range image without using an HDR converter.

Camera Technique for Capturing Two Exposures

1 Set up on Tripod
Before you start in Photoshop, you have to create the files so that each has a good exposure for a specific part of the image. For the files to align properly, it’s best to be on a tripod. Although handheld, rapid-fire, auto-exposure bracketing may work in some cases, I prefer the tripod approach. The tripod is definitely a must for long exposures, such as the photos in this example, which had shutter speeds of 13 and 25 seconds. I used a 5-stop, solid, neutral-density filter to force a long exposure time that would totally blur the surf.

2 Use Remote Shutter Release
In the images of Makapuu Point on the island of Oahu in Hawaii, the sky and most of the ocean looks better in the 13-second exposure, while the longer one reveals better detail in the dark foreground rocks. I also like the way the incoming surf is blurred into a fine mist in the 25-second shot. To minimize any chance of vibration that might yield a soft shot, I turned off lens stabilization and used an electronic cable release. For the purposes of this tutorial, the files are JPEGs, but I recommend you shoot RAW for the most control and quality.

Blend the Two Exposures

1 Bring Exposures Into One File
The first step is to bring the two exposures into a single layered file. For this example, we’re adding the darker exposure to the lighter image so that it will be the top layer. Select the Move tool (V), hold down the Shift key, and drag-and-drop the darker image onto the lighter one. Hold down the Shift key until the image appears in the lighter file as a new layer. This ensures that the two pictures are perfectly aligned.

2 Add a Layer Mask
Now we’ll add a layer mask to show only the “good” areas of the top layer. Depending on the nature of the images you’re combining and the complexity of the edge, this is the part of the process that will be different for each image. Some scenes may require intricate and precise masks, while for others a soft-edged mask will do; we’ll use a soft-edged mask for this image. With the top layer active, click the Add Layer Mask icon at the bottom of the Layers panel.

3 Paint the Layer Mask to Reveal the Lighter Image
Choose the Brush tool (B) from the Toolbox and set the Foreground color to black. In the Options Bar, set the Opacity to 50% and choose a soft-edged brush that’s large enough to cover the bottom part of the image (ours is 300 pixels). Check the Layers panel to make sure the layer mask is active (look for the highlight border around the thumbnail). Paint over the image where you want to reveal the lighter tones from the bottom layer (paint multiple strokes to reveal more of the lighter layer). Reduce the brush size to work on the areas where the two images meet at the edge of the rocks.

4 Add a Grouped Adjustment Layer
We lowered the Opacity to 20% and painted with black over the distant hill to show more detail there. To reverse the mask edits, press X to switch the Foreground and Background colors, and paint with white to bring back the darker layer. To add a contrast punch to the top layer, Option-click (PC: Alt-click) on the Create New Adjustment Layer icon in the Layers panel and choose Curves. Turn on the Use Previous Layer to Create Clipping Mask checkbox and click OK. Adjust the curve as shown. The clipping mask means that it affects only the underlying layer.

5 Debriefing
If you click on the Background layer’s Eye icon, you can see how the layer mask controls which parts of the top darker layer are visible in the final composite. Click again to turn on the Background layer’s visibility, then Shift-click the layer mask to temporarily disable it and view the darker image without the lighter foreground. Shift-click the layer mask again to turn it on. The soft-edged layer mask we used here works well because the long exposure times blurred the water and we don’t have to be concerned with lining up the waves.

Dual-Process Raw

1 Raw Exposure Strategies for Dual Processing
If you have a single exposure, and it’s a RAW exposure, then you can create essentially the same effect as in the previous steps. This is useful for scenes that contain moving subjects or where a tripod is impractical or simply not an option. The main thing you need to do in terms of exposure is bias the histogram as far to the right as possible without clipping the highlights (i.e., forcing the brightest areas to a total white). This ensures you have the best exposure possible for the shadows, which will help minimize noise in those areas.

2 Process Raw Files as Smart Objects
Process the first version of the image in Adobe Camera Raw for a specific area (in our example, we’re keeping the sky from getting too washed out). To preserve maximum flexibility, click on the blue Workflow Options link below the preview and turn on the Open in Photoshop as Smart Objects checkbox. Click OK then Open Object to bring the file into Photoshop. Choose Layer>Smart Objects>New Smart Object via Copy to create a duplicate smart object of the embedded RAW file (the smart object duplication must be done this way to apply different RAW develop settings).

3 Process and Combine with Layer Masks
Double-click on the thumbnail for the duplicate smart object layer to access the Camera Raw dialog and adjust as needed for specific areas. We used the Exposure, Fill Light, and Brightness sliders to show more detail on the rental surfboards. Click OK to apply these new settings. Now it’s just a masking job to combine the two. We used the Quick Selection tool (W) to make a basic selection of the bright sky, then used that to make a layer mask for the top Smart Object layer. We then fine-tuned the edges using a Brush tool at varying opacities.

Preview of Final Results

Double and Triple Strokes Photoshop Tutorial

Step 1

Open Photoshop and go to File>New for a new file at this size and click OK.

Step 2

Click the Text tool in the toolbar and click anywhere and type in some text. Don’t click-and-drag a text box, but instead just click once and then type so we can click-and-drag a corner to resize it later. I set the color of mine to #4891dc by highlighting the text and then clicking the color on the Options palette.

Step 3

Change the font to something that will look good with strokes, such as an san serif font (arial or verdana instead of times new roman). I set it to Maiandra GD. Then click the Move tool and click-and-drag a corner to make it a little bit bigger. Remember to hold Shift to maintain proportion. After resizing, press Return (PC: Enter) to apply resize.

Step 4

Go to Layer>Layer Style>Stroke.

Step 5

The Position should be set to Outside and set the size to 3. Change the color to one that looks good with the original text color.

Step 6

It should look something like this, depending on the colors you selected.

Step 7

Now if we went to Layer>Layer Style>Stroke again, we’d just bring up the options to edit the original stroke. Instead, click-and-drag the text layer to the New Layer icon the Layers palette (or press Command-J (PC: Control-J)). This duplicates the text layer.

Step 8

Now we need to edit the stroke on the lower, original text layer to make it larger. Double-click on the Stroke effect listed on the bottom text layer.

Step 9

Set the size to something larger, such as 6 pixels, and change the color to something that looks good with the other two colors. You could use Adobe Illustrator’s Color Guide palette or just wing it by sight or use a color wheel. Click OK.

Step 10

It should look something like this.

Step 11

Repeat the steps of duplicating a layer and changing the size and color of the stroke to add a third, fourth, or fifth stroke. Remember to edit the lower layer when wanting to make the stroke larger to show past the layer on top of it. Click-and-drag a layer below another if they get arrange in the wrong order. In this example, I gradually went from a royal blue to a different hue blue, creating a retro gradient.

Step 12

Of course, each stroke doesn’t have to have a color, just one to hide the color behind it. Try setting the first stroke to white, and then setting the second stroke to the same color as the text by hovering over the text when selecting the color (it will convert to an Eyedropper tool).