Why Focus Stack When I Can Just Use f/22?
I’ve got three good reasons why using f/22 won’t get you a sharp picture. However, even though I’ve proven these reasons in my own work, you should go try it yourself. The other day, I wrote a brief introduction to focus stacking (check it out here) and it has spurred a lot of questions and discussion on my Facebook page (including some guest pictures below). The major question posed there is “Why not simply use a small aperture to create a photo with great depth of field and get everything in focus instead of a process like focus stacking which requires post-processing to complete?” Everyone who commented about using f/22 to get focus throughout the picture has obviously never tried it .
In Focus ≠ Sharp
Lots of people with Ph.D.’s in physics have written good articles about diffraction and why you shouldn’t shoot at the lens’s smallest aperture (I’m using f/22 to represent your lens’s smallest aperture, which may be smaller or larger than f/22). You should go read those. I believe them, and I’ve experienced the fact that f/22 often doesn’t produce the sharpest possible photo.You can also read about hyperfocal distances which allow you to get everything in a scene in focus by focussing at a specific distance and a specific aperture/focal length combination. I made this photo using a hyperfocal calculator in the Field Tools app. This works well, and I’ve used it quite a bit. But being in focus doesn’t mean the picture will be sharp.