This week's theme for my personal photography project, the Pet Photography 52 Weeks Challenge is "High Dynamic Range". Today's cameras are amazing, but they can never match the human eye. A camera can’t adjust for shadows and highlights in the same scene. In a high contrast scene, one with both bright light and shadows, it's impossible to expose correctly for both. You either must leave some shadows in the the dark, or risk "blowing out" your highlights into white areas of your image that contain no detail whatsoever.
Luckily there's a way around that and it's called HDR photography, or high dynamic range. HDR photography solves the dilemma of what to expose for, the shadows or the highlights, by merging several exposures together to expose for them both. With HDR photography you can have your cake and eat it too! HDR reveals details lost in the shadows or highlights of a single shot by merging several images, all taken at different exposures, together into a single image.
Below is a typical example of an HDR image; part of the scene is shaded, part is lit by the sun, so there's high contrast yet the image is perfectly exposed throughout.
Piazza Navona - Photo Credit: Wikimedia Commons
You may have already figured out by now that merging multiple images together means that it's pretty important that all our frames are taken from the exact same point of view, so a tripod is a must. Tripods and dog photography don't usually go together! I've played around with HDR images in the past, but with still landscapes or buildings. Not with a dog. That moves. Sometimes a lot! But this is a pet photography blog project and thus there needs to be a pet in my frame!
Ginger's got a pretty good stay, but I wasn't convinced that she could hold perfectly still for multiple exposures (if she moves, the merged images will have a "ghost" effect on them where her body doesn't match up from frame to frame).
So I had the bright idea to take several exposures of the scene and insert her into one where she would be correctly exposed. After merging all the images without her, I would then put her in the scene via a little Photoshop magic.
You can see in the image with Ginger that she's perfectly exposed, however the shadows under the overpass contain little to no detail. Additionally, I've got some blown out highlights where the sun is peeking through.
It was a good idea, and it worked, but Ginger "not HDR" looked fairly incongruous with the rest of the scene in HDR; I wasn't happy with the results. I then tried something else; I took the 6 frames and merged them see if Ginger would appear in the final merge (it's a bit like making sausage - you put the images into the HDR software and wait to see what comes out on the other side). Nope, that didn't work either. I had a great HDR image, but no Ginger.
I did a bit more research and I tried a workaround that I read about. I took the single image of Ginger where she is correctly exposed and created two virtual copies of it in my editing software. I then changed the exposure to one by +2 stops and decreased the exposure of the other by -1 stop and merged those 3 images.
Success! Better results with that and no worries about "ghosting" if Ginger moved an inch. I ended up with a green, glowy scene under the overpass and Ginger is a bit glowy too, but at least now she matches the rest of the scene. I really like the bright green reflections in the water. I'll definitely look to do this again when faced with a high contrast scene now that I've got a few tricks up my sleeve!