One of my goals this year is to improve my photography skills so I can create better photographic references for studio paintings. I have read over and over again that cameras are not equipped to capture the true essence of a scene like our eyes are, and that painting from life is the only real answer. In principle I wholeheartedly agree, but my current life situation does not afford me the luxury of setting up my easel in the middle of Times Square at 11:30 at night to paint. Besides, camera technology was no where near where it is today when John F. Carlson wrote his treatise on landscape painting, in which he condemned the use of cameras for capturing nature. If I have to paint from photos for the time being, my primary task is to try and capture as much of a scene’s impression on the silicon sensor of my digital SLR as possible.
One way to capture high fidelity images with my DSLR is through multiple exposure HDR photographic techniques. High Dynamic Range (HDR) photography is becoming quite popular with the advent of high resolution cameras and the increasing affordability memory storage. HDR techniques allow a greater dynamic range of luminances between the lightest and darkest areas of an image than standard digital imaging techniques or photographic methods. This wider dynamic range allows HDR images to more accurately represent the wide range of intensity levels found in real scenes, ranging from direct sunlight to faint starlight.
Having read up on HDR last week, I was eager to take my camera and new found knowledge to New York City on a two and a half day business trip to capture some HDR-ready images. This was how day one went: catch an 11am flight to LaGuardia, land at 4:30pm, dinner at 6:30 at Il Postino with business colleagues, back to the room at 50th and Lexington at 10:30pm, grab camera, lenses and tripod (required) and shoot Times Square until midnight. On day two, I was able to squeeze an hour and a half of shooting in Central Park in before dinner. It was a bit chaotic but honestly, one of the perks of business travel is the opportunity to see many great things and explore creative outlets that would otherwise be unattainable.
One cool thing about New York is you can probably run around naked and no one would really care. During my shoots, I trucked around my fully extended tripod and camera and plopped it down any time I saw something that caught my eye. For every shot, I took three exposures. The first shot was spot metered on the subject, and the other two were shot two steps above and below my first. My Canon 50D can take all three exposures automatically with a simple menu setting called auto exposure bracketing. The three exposures allow me to capture the full dynamic range of the light in both the shadow and lit portions of the scene. I also shoot in RAW mode, which is the actual sensor data from the camera. Since the RAW picture format is not compressed, it allows me to have a lot of control during the post processing stage with the computer.
Each image contains about 150 megabytes of data. Once I have the image back at home, I use HDR software called Photomatix Pro to merge the three exposures into a single HDR image. I then take the HDR image into Photoshop as a base layer and bring in the original exposures into separate layers so I can use a variety of masking and editing steps to tweak the final image to my liking. Since I was at the location while shooting, I can use my memory to try to recreate the first hand visual impression of the scene. When I am happy with the result, I do a final crop and save the image in a standard picture format.
If you are interested in learning more, I found an excellent tutorial here that will help you get started. It is a bit of work but the end results can be quite satisfying.