Will my images be okay at f22

[Paul Bartok]

In terms of refraction, can I shoot nice clean image's at 90mm f22 on 645, I know on 35mm they say don't go to f22, ideal is f16 does that change for medium format? The lens can go upto f32 and the other lens f42

[Dom Jaeger]

I think you mean diffraction, not refraction. And yes, it changes depending on the format size, which is why larger format lenses often go to far smaller apertures than 35mm lenses. The focal length is irrelevant.

 

Whether f/22 on 645 is clean enough for you is somewhat subjective, how big are you blowing up the image? Generally speaking, you'll notice some diffraction softening past f/16, but f/22 shouldn't be drastic. The only way to really know is shoot some tests.

 

But you'd probably get a more educated response on a forum dedicated to medium format photography rather than cinematography!

[Mei Lewis]

Think you mean diffraction not refraction.

 

It softens the image overall, how much that bothers you is a personal thing and depends on what you're shooting.

 

I've gone to very narrow apertures to maximise DoF for a forced perspective shot. Moving image with its much lower resolution than stills I don;t think this is so much of an issue.

[Paul Bartok]

Cheers, I'll run some test's once I receive my new roll's :)

[Stephen Williams]

In terms of refraction, can I shoot nice clean image's at 90mm f22 on 645, I know on 35mm they say don't go to f22, ideal is f16 does that change for medium format? The lens can go upto f32 and the other lens f42

 

I would not go past 8 or 8/11 on S35.