Tuesday, July 6, 2010
These three images are taken from a sequence I took with the new Canon 7D. There are 7 totals images, all taken within 1 second showing the redtail hawk launching off of the lamp post.
One of the problems I had with my old camera (a Canon Digital Rebel XT) was getting exposure right. You could tell the camera to be in all-manual mode, shutter preferred mode, or aperture preferred mode. The ISO was only set by hand.
On occasion I wanted an additional auto-adjustment. The Canon 7D also has an auto ISO adjustment which is very close. I set the shutter speed and aperture, and the camera figures out the ISO needed to get the shot. Given the wide range of ISO (100- 6400) that allows for a very broad range of exposure. This particular series was ISO 640, which would be very noisy on the Rebel XT but quite reasonable here.
Especially if you use a technique I read about (sorry, I can't remember where) where you stack multiple layers of images and average across the layers. I haven't had a chance to play with this yet, but it looks really intriguing.