Tuesday, November 13, 2012
You're supposed to use a tripod when bracketing images for high dynamic range (HDR) processing. I have always, well usually, followed this rule. This insures that the images line up properly and when over exposing by two stops, the shutter speeds can be a little long for hand holding.
A few weeks ago I was on Peebles Island making trail scenics and decided to bracket exposures by one stop just to have options for post processing the single images. Later, I decided to try HDR processing some of these three shot series despite the fact that I had been handholding during the bracketing. While some were too out of alignment, others worked well enough for combining the images.
Yesterday, on a nice sixty degree November morning, I decided to intentionally try and bracket three handheld images for HDR processing as I hiked the island.
Knowing that alignment would be the important issue I made some decisions to minimize any problems. First, I only bracketed over and under one stop from the metered exposure. Second, I made sure that the slowest shutter speed was fast enough for sharp handholding. Third, I set the camera for continuous shooting and held the camera steady as if it were one long exposure.
I think the results were decent and I didn't notice any of the shots being blurry due to misalignment.
All images were made with a Canon EOS 5D mark II with the EF 24-70mm f/2.8L USM lens at f/6.7 and ISO 200. Shutter speeds ranged from around 1/125 sec. for the over exposed shot to around 1/500 sec. for the underexposed shot. Here are some of the results:
As far as HDR processing goes, for this series I used Photomatix Essentials and it's "Photographic" presets to process the unaltered RAW images. Then the JPG images were sharpened a bit and saturation increased a bit in Digital Photo Professional.
A better workflow might be to sharpen and deal with white balance and lens aberrations in DPP first, save the RAW files and then apply the HDR processing. I have done that when using the 17-40mm lens to correct peripheral illumination and distortion. Since I've still got the unaltered RAW images, I can always do that at some point in the future with these shots.