Tutorial: High Dynamic Range, Even With Moving Subjects
High Dynamic Range Imaging (HDR) enables you to capture stunning images that display all the vivid color and contrast that is usually only visible to the human eye. You cannot duplicate HDR by manipulating a single RAW image in Photoshop.
Contrary to popular belief, you can photograph people and moving objects using HDR. It requires more editing time in Photoshop, but not as much as you might think.
This significantly broadens the commercial applications for you in your business. You can offer your wedding clients unique images of the church and select outdoor locations. Your commercial clients will see the enormous differences between HDR and regular digital images.
Offering HDR also separates you from the competition, but more importantly, places you far ahead of the ever-growing amateur photography crowd.
How to take an HDR Photograph
HDR images are created by taking 3, 5, 7 or more photographs at 1 to 2-stop exposure increments per photo. The photographs are then merged into a single image.
I shoot sets of 5 or 7 images at 1-stop increments. I generally shoot in sets of 5 for outdoor locations during the day and sets of 7 for indoor settings, like churches or hotels. The darker the scene, the larger the set of images. Ideally, you want shadows blown out in the overexposed image and highlights made dark in the underexposed image.
Camera Set-up & Equipment
Most DSLR cameras have an auto-bracketing feature. This allows you to press the shutter release and your camera will run through your set of images automatically, at the exposure increments you designate.
You want to keep your aperture setting the same throughout the set of images and have your camera in manual shooting mode. I sometimes go as high as f/16 if it’s a static scene, like the inside of a Church. However, when there are people or moving subjects in the scene, I want to run through the set as quickly as possible. Depending on lighting, I use f/5 to f/11. This makes it easier to remove the ghosting between images in Photoshop. I setup my camera and wait to get a shot with as few people in it as possible.
To get the sharpest possible photograph, you will want to use a tripod or setup that keeps your camera completely still. It’s preferable, but not essential, to use a remote shutter release to avoid touching the camera to start the exposures. You can photograph HDR on the fly, handheld, but you should at least lean against something solid like a wall, lamppost or railing.
Always shoot in RAW
There are several reasons for always shooting in RAW when working with HDR. Two issues with HDR are a tendency for more noise and artifacts. Artifacts are areas of detail in a photo, like intricate stained glass in Cathedrals, that show black areas of missing detail or colors that are wrong. Nearly every time I have used JPGs with Photomatix, I have obtained worse results than with RAW files, sometimes far worse.
However, it’s a little different when using Dynamic Photo HDR. Sometimes I get better results using JPGs on certain photographs, so I’ll try JPGs if I get unacceptable results with RAW. But these JPGs were converted from my RAW images after being customized in Adobe Camera RAW. That's a far better method than relying on my camera to put in generic JPG settings.
HDR Workflow Overview
• Pick winning sets in Adobe Bridge, Lightroom, ACDSee etc.
• Batch process sets to basic HDR Image in Photomatix Pro (see HDR Software Workflow PDF)
• Tone map HDR in Photomatix & Dynamic Photo HDR
• Compare and keep the best shot
• If necessary, apply noise removal with software such as Neat Image, Noise Ninja, Nik Dfine
• Remove ghosting in Photoshop
• Creative enhancement in Photoshop
• Selective sharpening in Photoshop (always sharpen last)
Software to process your HDR
Although you can process HDR images in Photoshop, (using File > Automate > Merge to HDR), I prefer using HDR-specific software like HDRsoft’s Photomatix Pro or MediaChance’s Dynamic Photo HDR. I have not been able to get the same results using Photoshop. I use Photoshop to enhance the image and remove ghosting after I’ve tone-mapped in HDR software. The final step in Photoshop is selective sharpening.
Photomatix Pro has an easy-to-use interface and intuitive controls, (see HDR Software Workflow PDF for a quick overview with screenshots). Once you have created the initial 32-bit HDR image, you move on to the creative part, tone mapping.
There are two ways to tone map in Photomatix: Details Enhancer and Tone Compressor. The Details Enhancer gives you far more creative flexibility. I only use Tone Compressor for night shots. I find that night shots processed with Details Enhancer get very noisy.
At the bottom of Photomatix’s group of sliders on the left you will find presets. You can save and load presets from here. Photomatix will apply your previous tone map settings to the next image you open. Sometimes I want to start from scratch and apply Photomatix’s default settings (found in the presets drop-down).
As every photographer and photograph is unique, I do not have any Photomatix slider settings recommendations. I will say that the strength slider is the main component for producing the popular surreal HDR effect. Most of the time I keep this at a low setting, around 50-60, but for the right photo, I’ll introduce more.
My workflow consists of finding what works for a particular photo, then saving those settings as a preset and naming it something relevant for that type of photograph. Many times I will load one of my existing presets that will get me close to the type of look I want, and then make slight adjustments with the sliders.
Batch Processing In Photomatix
The batch processing feature of Photomatix is very useful and easy to use. First, drag your HDR sets of RAW images into a new folder on your computer. In Photomatix, once you click ‘batch processing,’ a dialogue box pops up. In the dialogue box you can have Photomatix apply generic tone mapping settings to each photograph, but I prefer to individually apply those settings myself.
If you have 10 or more sets of HDR images to process, having Photomatix create the basic HDR saves you a signifcant amount of time. You can now invest your time on the most important part—tone-mapping. You can also open the basic HDR image and tone-map in any program that can process HDR.
Dynamic Photo HDR
MediaChance's Dynamic Photo HDR interface is very different than Photomatix (see HDR Software Workflow PDF). Once the software opens, click Create HDR File. In the dialogue box that pops up, click Add Images and navigate to your set of HDR. After you load your images and click OK, you have an extra step of checking that your HDR set is correctly aligned. Sometimes the software aligns them fine automatically, other times you may have to align them manually by using the arrow keys on your keyboard. When finished aligning, click OK and then choose Tone map HDR file.
Dynamic Photo HDR gives you many creative options. In the tone mapping dialogue box, under Method, you have some interesting presets to click through. I usually start with eye-catching, and then alter the sliders to suit my photograph. You can experiment with different preset effects by clicking the Filter: Color button at top right.
Another unique feature of Dynamic Photo HDR is the ability to have what I call instant presets available for the image you are working on. Once you get your image looking good, you click on your HDR image in the tone mapping dialogue box. This gives you a smaller sample of your tone mapped image with those settings applied to it. You can now move the sliders around and click on the image again to get another smaller version. You can click on these smaller versions to have it reload the settings that you applied to it. This is a great way to click through previous settings without having to manually load presets. (See PDF)
Dynamic Photo HDR works better with JPGs than Photomatix, and sometimes you get better results with a particular HDR image when using JPGs instead of RAW. If you are get excessive noise using RAW files, try it again with JPGs.
Finishing Steps in Photoshop
When I open my tone-mapped image in Photoshop, I duplicate the background layer and change the layer Blending mode to Soft Light. If the effect is too strong, back off of it by reducing the opacity of the Soft Light layer to 50%.
To remove ghosting of people and objects, I find the original set of RAW images that were used to create the HDR image. I chose the image that is closest to the color of the finished HDR. I then enhance the image in Camera RAW and Photoshop. Drag and drop that image into your HDR. Put a mask onto your HDR layer and paint on the mask to remove the ghosting.
My final steps include a Curves adjustment to see if the image needs more contrast or selective lighting in certain areas. The final step is selective sharpening using Unsharp Mask or High Pass sharpening.
Gavin Phillips is based in Chicago and specializes in teaching HDR and Photoshop. You can learn via webinars or hands-on training. Please see his website for schedules. http://www.photoeffects.biz/hdrtrain.html