Can we Collectively "know it" when only We Ourselves "see it" ? Locked

Started 8 months ago | Discussions thread
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Steen Bay
Veteran MemberPosts: 6,188
Re: There is no such thing...
In reply to Great Bustard, 8 months ago

Great Bustard wrote:

LTZ470 wrote:

Great Bustard wrote:

...let me get in a few words. First of all:

http://www.josephjamesphotography.com/equivalence/#diffraction

Diffraction softening is unavoidable at any aperture, and worsens as the lens is stopped down. However, other factors mask the effects of the increasing diffraction softening: the increasing DOF and the lessening lens aberrations.

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In terms of cross-format comparisons, all systems suffer the same from diffraction softening at the same DOF. This does not mean that all systems resolve the same detail at the same DOF, as diffraction softening is but one of many sources of blur (lens aberrations, motion blur, large pixels, etc.). However, the more we stop down (the deeper the DOF), diffraction increasingly becomes the dominant source of blur. By the time we reach the equivalent of f/32 on FF (f/22 on APS-C, f/16 on mFT and 4/3), the differences in resolution between systems is trivial.

In short, it is entirely possible for the FZ200 to be sharper at f/4 than it is at f/2.8, even though at f/2.8 it is already well within the realm of strong diffraction softening, and the lesser lens aberrations at f/4 may outweigh the increased diffraction softening.

Regardless, the effects of diffraction softening at f/2.8 on an FZ200 are identical to the effects of diffraction softening at f/8 on mFT and f/16 on FF, it's just that diffraction softening is one of many forms of blur.

Will have to disagree with you...diffraction limit...FZ200...not at f/2.8...

...as a "diffraction limit", except inasmuch as diffraction softening so strong that the resolution drops off to zero.

There is, however, a point where the effects of diffraction softening outweigh the effects of lessening lens aberrations, which depends on the lens, and which you might have understood had you read the above.

Also depends on where you look. The lens aberrations are usually stronger in the corners than in the center, so the point at which the resolution starts to decrease will most often be at a smaller aperture if looking at the border/corner resolution.

@LTZ470 - Is the FZ200 also sharpest at f/4 in the center, or are you just saying that the overall sharpness is best at f/4?

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