What kind of comments do you want? How much do you understand about exposure and how ISO/shutter speed/f-stop relate to each other?
Very briefly, given the same lighting conditions, 1/500 is a longer time to expose the sensor (or "film"), so the camera had to stop the aperture down to f/8. 1/1500, the camera selected a wider aperture to let more light in during the much more brief exposure time. If you wanted to go to 1/2000s, you would have had to bump up the ISO, unless you had a faster lens.
This is Photography 101 stuff, so either look into the Peterson book, or google around for a good tutorial on the web.
Good luck!
Originally posted by krs Generally the pictures look pretty good (to me at least)!
The following picture was shot in Tv mode, with a shutter speed of 1/500, and a resulting aperture of F8.0
This picture was shot in Tv mode with a shutter speed of 1/1500, and a resulting aperture of F4.5.
Both pictures were shot with a Sigma 300mm lens at ISO 200.
Comments would be appreciated!