Simply put, my question was: how often do you use f/22 (and smaller) in a long tele shot? Usually, I never go beyond f/11 or f/16. More than one year ago, I run into a beautiful subject with two sanderlings sleeping in the foreground and one dunlin in the background. Indeed I was near to a flock of birds, down on the sand, with the sun in good position and a good way to stabilise my long lens. I shot hundreds of photos and most of them (simpler subjects, such as one bird at a time) were fine (sharp, etc…). With the “two sanderlings + dunlin” subject I knew that it was impossible to get everything sharp, but I wanted to have the dunlin in the background less blurred as possible. So I went for f/40 (which was the smallest aperture given by the lens + multiplier). The image didn’t get as sharp as the others, of course, I suppose because of diffraction (and also because sometimes I don’t feel confident in myself, so I kept 1/160 sec. and consequently ISO rose up to 720, giving more grain and less detail). The dunlin was deeply blurred, anyhow.

So, I’m always questioning whether it makes sense to try such a shot, that perhaps is just impossible…

Thanks.