Photography of birds from helicopter (600ft Elev.) and adjusting exposure for better pictures?

Started Dec 11, 2012 | Questions thread
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GregF1970 New Member • Posts: 18
Photography of birds from helicopter (600ft Elev.) and adjusting exposure for better pictures?

A co-worker sent this question to me in the hopes I could help her, but her question is a bit beyond me.  So I am hoping this might garner some master responses here.

She shoots from a helicopter (average elevation of 600ft) with a Canon 7D and uses one of two lenses (Canon 28-135 f3.5 - f5.6 IS USM and a Canon 100-400mm f/4.5-5.6 IS L).  She shoots over the everglades, and her job is to take photos to help obtain bird counts in any given area.  Her goal is to get as clear as picture as possible to help aid in this count.  She is not looking for first place winning photos for clarity and color.  The issue is with shake of the helicopter she has to shoot with fast shutter speeds, but this causes dark images.  She can explain the rest...

She wrote;

Good day, I have a question on adding exposure compensation in post-processing RAW images. I typically shoot in aperture (AV, for portraits, general photos) or shutter speed (TV, esp when shooting out of helicopter) priority modes. But I don't have a good handle on use of exposure compensation. Because I'm typically photographing white birds from the helicopter, I often underexpose a bit if conditions are bright (to pick up the individual birds that blur together if I don't adjust the exp comp down a bit, or to pick up detail on the birds if I'm using the zoom lens). But on my flight last Wednesday, the conditions were really dark, so I left the compensation at 0. I was already trying a variety of shutter speeds w/ gyro-mount on my 7D, intending to reduce blur while shooting in our new land areas. Just didn't want to add in more variables to the equation (I had bird counts to do too).
I was shooting w/ ISO max'd at 800 & 1600. It was pretty overcast, so my shots got dark quickly (took shutter speed from 1/800 s to 1/8000 s). I was able to crank up the exposure in post-processing w/ the Canon RAW software, but there must be a price (noise, I imagine). The shot captured is what it is, so how does the program lighten it so much? (She's referring to Canon RAW Software) I'm assuming I would be better off adjusting exp comp during the shoot, but for that matter, if my aperture is already max'd out on my lens (f/3.5), & I've imposed a max ISO (note didn't select an ISO, kept it on AUTO ISO, but gave it max of 800 & then 1600, which the camera consistently used because of the low light), & I'm already imposing a shutter speed, what is the camera itself adjusting by increasing exposure compensation? I know, for instance, this setting isn't avail in full manual mode. Any thoughts appreciated!! Thanks!

She may be getting a dpreview account to review any comments or questions, so will I.

Thank you for your educated input on this matter, it is much appreciated.

 GregF1970's gear list:GregF1970's gear list
Canon EOS 600D Canon EF 50mm F1.8 II Sigma 18-125mm F3.8-5.6 DC HSM Sigma 70-300mm F4-5.6 APO DG Macro
This question has not been answered yet.
Canon EF 100-400mm f/4.5-5.6L IS USM Canon EF 28-135mm F3.5-5.6 IS USM Canon EOS 7D Panasonic Lumix DMC-F5
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