I shoot landscapes with a 4x5 camera. Besides using swings and tilts, I've been using f/32 for my shooting aperture for all of my lenses from 75mm to 150mm and f/45 for my 300mm to make sure everything is sharp.
I just read an article in the current issue of View Camera where the author states he can already see the results of diffraction at openings smaller than f/22.
Have I been stopping down too much?. Should I be able to get adequate sharpness at f/16-22 with carefull use of swings and tilts?
I realize the true answer to this question depends on what I'm shooting but I'm looking for a general rule of thumb that I can work from.
Thanks in advance for your answers.