Best Aperture

[pico]

Advertisement (gone after registration)

Hmmm.... I think the diameter causing diffraction related softness is a "limit" and not optimal. Wider diameter is always theoretically better. Isn't it?

 

I agree that from a practical point of view, one may choose around f/5.6 for FF since wider aperture will have softer corners. But this is lens design issue and not a theoretical optimum.

 

Apertures large enough to have no significant diffraction are desirable if they have the aesthetics we want. Others have said the same thing in other words like "who cares" and "I trade-off depth-of-field..." and they are all right.

 

It remains that there exists a theoretical, in fact a real practical, concrete diffraction issue. Most of us don't care but I remind large format photographers that stopping way down is not a bad thing in most cases because the diffraction is not evident due to the low degree of enlargement required. If the resolution ideal for a lens is F/16 and they lose aesthetically desirable DOF, then it's silly not to stop down.

 

If one prints large from FF (24x36mm), then using lenses like 75mm up to 135mm with physically small apertures will degrade resolution when stopped down too far and it will be evident.

 

But like I've said all my life, resolution is highly over-rated, but still desirable at the aperture we prefer for aesthetic reasons.

[michaelwj]

But like I've said all my life, resolution is highly over-rated, but still desirable at the aperture we prefer for aesthetic reasons.

 

A photo without any resolution is just a grey card  .

 

If nothing else, your initial observations were interesting and have provoked some good discussions.

 

Michael