If you read my "Minimum Shutter Speed" thread, you probably know where I'm going with this. I'm just thinking about some dorky technical stuff, and I'd like to hear what you all think about it. Here goes:
Because of the crop factor with a DSLR, and most digital cameras, we use shorter focal length lenses to get an angle of view equal to 35mm film.
Focal length affects depth of field. Longer lens = less depth of field (at the same aperture.)
So, does that mean a small sensor digital camera gets more depth of field for an equal (to 35mm film) angle of view? Seems logical.
Along the same lines, it's a generally accepted truth that most lenses don't perform optimally at a wide open aperture. So, to get the sharpest shots, we stop down a couple of stops. When we do this, does it improve the sharpness through out the frame, or only on the edges? I'm not sure.
IF...a big IF...it's only the edge sharpness that is improved by stopping down, and you're using a lens that was designed for full-frame 35mm on a less than full-frame DSLR, you wouldn't need to stop down as much to get the same sharpness, due to the crop factor.
I'm not sure all my assumptions are correct, but if we're able to preserve the lens sharpness using larger apertures on a DSLR, and at the same time we're using shorter focal lengths that give better depth of field, this equates to another low light advantage for digital.
Am I crazy...or just wrong?
Thanks for playing.
Paul
PS. I know this isn't going to make me a better photographer. I'm just curious.