Quote Originally Posted by ic-racer View Post
Like I posted previously, with the larger format your depth of field will be less and if you try to correct with a smaller f-stop your results will be limited by diffraction.
The link I gave, to a 5x7 1:1 shot of a moonflower, was done at f/45. I contact print it so that the subject in the print is almost exactly the same size as the real flower... no enlargement. Diffraction plays no role whatsoever. I could've shot it at f/64 or f/128 and it still wouldn't play a role. I could enlarge it 2x or 3x and it still wouldn't play a role at f/45. Really, try it!

Now... would the absolute sharpest possible result be at f/8 or f/11 or so? Yes, sure. True of all formats. But for LF and some MF, that matters not one iota unless you are shooting res charts. The smoothness of the tonality and the focus transitions in medium and large formats matter a lot more (to me) than whether you can see some minor difference under a loupe.

Not to slam 35mm, which is wonderful for a great many things including some macro work, and which I also use happily, but... the transitions between in focus and OOF objects can be rather harsh in 35mm. You can see focus/defocus lines. With the larger formats, the transition from in- to out-of-focus portions is generally much smoother and more gradual.

Also, as I mentioned, a tiltable bellows gear can eke a lot more effective DOF from a wider aperture than a 35mm system with extension tubes. When I do macro with a view camera, I focus first of all with the lens wide open, then use tilts to bring as much into focus as I can, and then start stopping down, etc., if the DOF is insufficient.