This is the second part of a two-part series on creating High Dynamic Range Images (HDRI) from a single exposure, written for the Canon Digital Learning Center by Ron Berard:
- Part I: Overview, Capturing and DPP Processing Techniques (click to read)
- Part II: Processing and final image manipulation
Generating an HDR Image in Photomatix
If you recall from part one of this article, there are basically two different groups of images you can bring into HDR software for conversion:
- The three images produced in DPP from the single image method.
- Or, the multiple files we saved from the nine separate images created by bracketing exposures with the camera as part of the multiple image method.
- For the purposes of this article, let’s focus on the single image method. For me, Photomatix Pro is the software of choice.
- Start by launching the software. Click on FILE > OPEN then retrieve the three images you created from the one RAW exposure in DPP, and bring them into Photomatix.
- You will then be asked what to do with the dragged files. Click on “GENERATE AN HDR IMAGE.” then click OK.
- The next screen will ask you to confirm the three .TIFF files that will be converted. The files will appear inside the box (if you don’t see the files, click on the browse button to locate them). Click OK to confirm.
- The next screen will ask you information about your exposures or EV scale. Note that I set the Value at ‘2’ – in this case, because when these files were processed in DPP (see Part 1), the “brightness adjustments” were set in 2-stop increments (2 stops underexposed, normal/zero, and 2 stops overexposed). Set it to the number that corresponds to your bracketed exposure settings, then click OK.
- The next screen will ask the OPTIONS you want to set. Because I used the single image method in this example, the “Align Source Images” and “Attempt to Reduce Ghosting Artifacts” do not need to be checked (however, if you are composting multiple, brackerting exposures, both would typically be checked). I also did not check “Reduce Chromatic Aberrations” or “Reduce Noise” because I would prefer to deal with these issues in Photoshop. In my experience, Photoshop does a more effective job of handling noise and edge-to-edge sharpness, although Photomatix does offer some correction. Ultimately, the only option checked that I recommend using is “Take tone curve of color profile.”
- Then click on “Generate HDR”, and wait about 30 seconds as Photomatix Pro creates the HDR Image. The resulting image will probably look very contrasty, but don’t worry. This is because it’s in 64-bit. To see how it really looks on 16- and 32-bit monitors, you will have to click on the “Tone Mapping” tab. The next screen shows a default view of what your HDR image looks like, pre-adjustments.
At this point, you can start to really play with the image using the tone map settings menu/tab. Two option groups make up these settings: The “Details Enhancer” and “Tone Compressor.” In my workflow, the “Details Enhancer” functions are used much more commonly than the “Tone Compressor” options (they just doesn’t give as many different views or range of creativity. You will see that for a more natural look in your image, the dials generally seem to be more to the right. For a more extreme look, your dials will move more to the left.
Here are my typical preferred ‘Details Enhancer’ settings:
The first on the list is STRENGTH. This scale covers the overall contrast of the image. The range that seems to be most used is between 60-100. Experiment with it, as the right amount will vary from photo to photo.
COLOR SATURATION is also a scale that seems to look best at about 50-75.
Obviously the more saturation you like, the higher the scale moves from 50. If you prefer less saturation, then lower the scale from 50.
I usually keep the LUMINOSITY scale at 0. Moving it to the right will lighten and flatten your image while a move to the left of 0 will add contrast to the picture.
The LIGHT SMOOTHING function can be very liberating to the image. Most of the time I will choose “Very High”. This setting will initially control the amount of HDR in your photograph. If you want an image that borders on surrealism, then pick one of the first two buttons from the left.
The MICROCONTRAST scale I find is usually best when set from 4-8. This function controls the amount of contrast in certain parts of the image.
What comes next under the histogram are your TONE SETTINGS. The three Tone Settings (White Point, Black Point and Gamma) are fairly subtle. Many HDR proponents leave both the White and Black Point settings at 0, with the Gamma setting right down the middle (.85). Personally, I find the ‘0’ White Point setting causes my images to be a little too flat, so I boost the contrast a little by moving the scale to the right (the Black Point setting is even more subtle; you have to move that scale quite a bit to the right to get any kind of noticeable change in the image). The Gamma scale covers 200-35, from left to right. Setting it right down the middle is a good starting point. Moving the slider to the right will make the image lighten and ‘flatten’, and it will also bring up the noise factor as your scale moves closer to the right edge. Moving the scale to the left adds a little darkness, richness and some contrast.
Under COLOR SETTINGS, Temperature, Saturation Highlights, and Saturation Shadows all seem to be just fine with a setting of 0 or close to zero. Moving the Temperature slider to the right will add warmth to the image, and moving it to the left will give your image a cooler look.
The Saturation Highlights and Shadows scales are very subtle, and really only work on certain parts of the image. Most of the time, all three will work well set at or near the middle.
The SMOOTHING SETTINGS I find are best to keep all but one of the four options settings at or near ‘0’ (all the way to the left). The exception is Highlights Smoothing, which I prefer to set in the middle, at or near 50-75.
At the very bottom of the tone mapping settings you will see a default tab with an UNDO and REDO button along side. By hitting default, you can start over with your custom settings.
You can also save and name your custom settings by clicking the drop down arrows to the right of CUSTOM. I have eight custom settings that I normally run through my images to see if any one of the presets works better than the others.
After you’ve decided on your settings, and processed your image, you can either leave the settings the way they are until you bring in another set of images for HDR, or you can click on your DEFAULT button to bring all of your scales back to where they were when you started.
In spite of my recommendations, you should experiment, and remember the same settings will not always work on different types of images. Once you are satisfied with the results, drop down to “Save Settings” and name your custom settings for future use as a preset. I have several (blueskypuffycs, citystreets, Koslowski, etc.) in addition to the Photomatix default, and I select my preset depending on the lighting, subject, colors, and other considerations for each image I process. Here are examples of my custom settings and how they reflect on the image:
Once you are satisfied with the results of your tone mapping settings, click on the “PROCESS” button. Photomatix Pro will then merge everything together. Name the image and choose your format (I usually save mine as a .TIFF file), then save it in the folder of your choice. At this point, basically, you are done.
HDR Post Prcessing -- My Secret Weapon
Yes, once you have tone mapped your image you are pretty much done with HDR creation. However, I have a little trick of my own I use to further enhance my HDR imaging.
I especially use this one last step when I am working on creating HDR from a single image. This last step requires a Photoshop plug-in I purchased a while back from a company called Topaz Labs. They offer a Photoshop creative exposure plug-in called “Topaz Adjust.” This plug-in includes several preset filters, representing a range of photo effects from subtle to psychedelic -- some are as simple as smoothing your image or giving it more detail, or a color boost, and there are many that give your image a more extreme HDR effect. You can use the presets ‘as-is’, or tweak them using any of several Exposure, Details, Color, and Noise slide adjusters and save those adjustments to create your own unique presets. The current Topaz Adjust plug-in sells for about fifty dollars, and they offer a free 30-day trial.
Here is an overview of how I use Topaz to add the final flourish to my HDR images: To begin, launch Photoshop, then bring in your HDR image. Click on the FILTER tab at the top and scroll down to TOPAZ LABS, then TOPAZ ADJUST.
As I mentioned on previous page, there are 21 presets to Topaz Adjust and each one gives you a thumbnail of what your image will look like with that filter (my all time favorite is “SPICIFY”) After choosing the preset I want, click OK and wait for the final result.
Hopefully, this article will act as a springboard to any photographers interested in taking your images to the next level using High Dynamic Range. Remember, you can take it as little or as far as you want – whether you want to capture images more ‘naturally’ (the way your eyes see it), or create something much more surreal and unique. Don’t get discouraged if your first experiments are frustrating or don’t produce the results you want. Like anything else, it will take a little practice to find the combination of equipment, shooting method, processing and post processing software, etc, that work best for you.
Also, consider your subject choices. Many associate HDR with landscape photography; I found that photojournalistic street photography was an ideal HDR subject, and have concentrated on perfecting those types of images (as you can see from this tip). But there are so many other subjects that HDR plays well with. For example: Long exposures, where different degrees of light enter the picture. Or, working at dusk or dawn. How about bringing flash photography to the table? Architectural and panoramic photography can also be enhanced greatly with HDR.
High Dynamic Range Imaging is arguably one of the more exciting trends in digital photography. Like any trend, it has its loyal fans and disapproving critiques (and everyone in between). Personally, I look at it as an enhancing tool. Interestingly, my use of HDR techniques is starting to change the path of my career. I used to produce straightforward editorial photography. Now I have quite a number of HDR images mixed in with my other work, and find myself having to redefine my field -- am I still a photojournalist or have I morphed into a more creative commercial photographer (there is no doubt that HDR has made quite an impression in the advertising world)? It’s an interesting, though not unexciting, dilemma that (as of the time of writing this article) I still don’t have a firm answer to…
Ultimately, I think the creative potential of HDR lies with the software and how far designers/programmers are willing to push the envelope. Meanwhile, photographers and their devoted viewers will dictate how long it remains popular and relevant. However long the HDR trend lasts, have fun experimenting, and making the most of this dynamic technique.
The CDLC contributors are compensated spokespersons and actual users of the Canon products that they promote.
All images are copyright Ron Berard