HDR Tutorial

Those of you who follow me on Twitter or Flickr, might have noticed that I recently started posting more and more HDR photos. In case you haven't heard of HDR (high dynamic range) before: it's a technique to enhance the dynamic range of a photo, which results in more details in both dark and light areas.

To start with I’d like to point out that you can achieve HDR like effects with just a single photo. The perfect tool to achieve this kinda effect is Topaz Adjust ($49.99). It gives you full control over exposure details and color and really makes your images pop. I will post a follow up tutorial on how to get the most out of Topaz Adjust. However in this tutorial we will focus on how to create real HDR photos based on three differently exposed photos.

HDR Basics

As mentioned most HDR photos are more or less a composition of three photos, each of which taken at different exposures (usually -2 stops, normal, +2 stops): the underexposed image provides details in the lights areas, the overexposed one details in the dark areas and the correctly exposed variant is responsible for the details in the mid tones. In our case I took some photos of a church in my hometown Graz. Churches are a really nice example of how to bring the most out of HDR photography, since normally there will be bright light coming in from the windows as well as lots of darker corners. It’s simply impossible to capture all of the nice details with just one shot. At least with cameras available today. Anyway… here is the footage we gonna use for this tutorial.

Taking photos

Btw I’d like to point out that you really don’t have to use any of the top camera models to achieve a good HDR photo. Actually any camera that allows manual over- or under-exposure of photos can be used to create HDR images. If you own a DSLR you might be familiar with your bracketing or even auto bracketing feature of your camera. That’s exactly the feature you should use to take the three photos. There is just one thing you should keep in mind: we gonna combine the three photos in a next step and thus it’s really important that they are congruent. Sure there are bunch of different tools to make your photos match (like Photoshop’s auto align feature), but to make sure your footage is as good as possible I really recommend using a steady tripod and maybe even a remote release to reduce camera shake as much as possible. Personally I use a simple Manfrotto tripod and a Nikon remote release.

Software

Even though there are certain techniques to create HDR photos in Photoshop, most people I know (me included) prefer another tool: Photomatix by HDRsoft. Photomatix comes as a standalone version or as a plugin for both Apple Aperture and Adobe Lightroom and is priced between $39 and $119. They even offer a reduced pricing for students, teachers, charities etc. And in case you wanna save another 15%, be sure to use the Photomatix coupon code “BARTELME”. So check it out.

Processing

In a next step we have to bring the three different images to Photomatix. For that purpose you can either simply open the images in Photomatix or send them to Photomatix directly from within Aperture or Lightroom. In Lightroom just select the three photos, right click and choose “export - Photomatix” in the context menu. This will bring up a dialog with a couple of different options. Make sure you select “Generate HDR image”, “reduce chromatic aberrations” and “reduce noise”.

The last setting is really important, since generating a HDR photo will always produce some noise. Alternatively you can leave this particular checkbox unchecked and remove the noise in later step using a dedicated noise reduction tool, such as Noiseware Professional. Also if you didn’t use a tripod, make sure to check “align images”… actually I keep this one checked all the time, although I always use a tripod. The last checkbox is also kinda nice: this will make Photomatix automatically send the processed photo back to Lightroom and stack it with the three original images. I use this all the time.

Once you click “Export” Photomatix launches and starts processing the images. This may take while, depending on the resolution of your images and the processing power of your computer. After that Photomatix will open a window with a first version of your HDR photo. Although it might look interesting, it’s not the final version yet.

In a next step we have to tone map the photo to reveal the image details in highlights and shadows. After hitting “Tone Mapping” a new palette pops up with a bunch of different options and sliders. Also note that appearance of your photo has changed… in most cases it will look even worse than the previous version. Don’t worry, it will get much better in the next step.

Tone Mapping

Now let’s fine tune the image. The strength slider controls the strength of the contrast enhancement. I prefer to move it all the way to the right. The saturation slider… well increases the overall saturation of the image. Personally I really like vivid images, however you can easily overdo the effect. So play around until you get the effect you’re after. The luminosity control is where it starts to get interesting: Moving the slider to the left will result in a more natural look, moving it to the right brightens the image and gives it a somewhat painterly look.

The microcontrast slider sets how much local details are amplified. A higher value gives a sharper, a lower one a softer look. The “Smoothing” setting has an important influence on the look of the tone mapped image. High values give a more “natural” look, low values a more “artificial” look. I kinda prefer the natural over the artificial look… but as mentioned before, this mainly depends on your photo and of course on your personal taste and style.And finally you can define the contrast of your image by adjusting the white and black point as well as the gamma. The more you move the black/white sliders to the right, the higher the contrast of the image will be. The “Gamma” slider adjusts the mid-tone of the tone mapped image, brightening or darkening the image globally.

In the “color settings” section you can fine tune the temperature and saturation of your image and the “miscellaneous” section enables you to even more fine tune how certain parts of the image should be smoothed out. To be honest I rarely use these settings, but feel free to play around. Each photo is different. When you’re done press the “Save and reimport” button on the bottom of the panel to send the processed image back to Lightroom. Here is the final result.

So I hope I could give you a nice introduction to the interesting field of HDR photography. Feel free to play around and post your results to my HDR flickr group. Looking forward to your photos!

And by the way, you may also wanna check out the Belorussian version.