Thinking about diffraction limits on APS-C type sensors

[oryzain]

Guys out there using dSLR, I happened to check out this site http://www.bobatkins.com/photography/technical/diffraction.html.
Nice outlay with examples about how diffraction correlates with aperture size. Also happens to clear some hazy perceptions about the dSLR vs film SLR useage about the higher f values!

 

[westwest1]

er...does it mean we must use FF camera only to get good image...not really understand...

 

[ExplorerZ]

er...does it mean we must use FF camera only to get good image...not really understand...

nope. i think it simply means with a 35mm ff cam, one can use higher f-stop without the problem of diffraction.

 

[oryzain]

Basically tells that diffraction effects are dependent of sensor size not the pixel density.
Compares lens performance as a based at different f-values, and shows that sharpness of lenses increases a one goes on stopping down the aperture then loses sharpness if we further decrease aperture. Kind for a APS-C sensor it should be between f7.5-11 for maximum sharpness.

 

[denmad]

ExplorerZ is correct. More specifically, for APS-C sensors, the maximum aperture that can be used before you suffer a loss in sharpness is f16, while for FF, this is f22. However, as shown in Bob's tests, stopping down to f8 or even f5.6 should remove most of the abberations in most of the lenses, so f8-f16 is more than enough range for getting minimum aberation and enough sharpness, for 8x10 prints.