300mm lens which is sharpest aperture

[Kirk Fry]

I did this once. Set up some USAF targets and shot a bunch of my lenses at 20 times focal length. Yikes, at f22 you couldn't tell the difference if I had not labled the target as to which lens it was. Even my cheapo angulon was great. I did the f stop thing too and examined the results with a MICROSCOPE. You could see defraction start to set in at f64. But not with the naked eye. So my conclusion is that just about any lens is way better than I am. Stop sweating it and buy a tripod. DOF will be your major problem and f64 helps here.

Kirk

[Christopher Perez]

Right on!

Your experience closely mirrors my own on the topic.

BTW, there's nothing cheap about an Angulon. Well, except sometimes the price. But maybe that's what you meant by "cheap".

I did this once. Set up some USAF targets and shot a bunch of my lenses at 20 times focal length. Yikes, at f22 you couldn't tell the difference if I had not labled the target as to which lens it was. Even my cheapo angulon was great. I did the f stop thing too and examined the results with a MICROSCOPE. You could see defraction start to set in at f64. But not with the naked eye. So my conclusion is that just about any lens is way better than I am. Stop sweating it and buy a tripod. DOF will be your major problem and f64 helps here.

Kirk

[Maris Rusis]

Putting my Fujinon-W 300 f5.6 on my optical bench and examining the aerial image with a microscope I find that flare decreases, contrast increases, diffraction increases as I stop down. The absolute best mix of minimal abberations is at the half stop between f. 11 and f. 16. In the twenty years I have had this lens I have never used this aperture for actual film exposure.

By far the worst aperture is f. 90. I use this aperture often but since the final photographs are gelatin silver contacts the actual aerial image defects come through alright but too small to see.