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04-24-2016, 02:18 PM - 1 Like   #16
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Don't confuse extra depth of field for extra perceived sharpness when examining diffraction. Diffraction kicks in nearly the moment you click your lens one stop down. Your sensor may not pick it up. The increase in depth of field plus the blocking of stray light rays more than makes up the diffraction at relatively large-ish apertures like f/4 but the balance starts to sway the other way after some point. Remember, most of this only noticeable when pixel peeping. Otherwise, just enjoy the shot.

04-24-2016, 09:51 PM   #17
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Hmm, I think you want me to not worry about diffraction at smaller apertures based on lens tests. The consequences of diffraction depend on pixel pitch, and that's not parameterized on lens reviews...so while I get the point (I think), using lens reviews done against a 16MP sensor says nothing of diffraction at 24MP.

The moral of the story is - just test your lenses on your body for goodness sake. Make up your own mind what's acceptable. It might take 30 minutes, then go shoot something worthwhile.

My samyang 135/2 is practically as sharp wide open as it is stopped down to any aperture.
04-24-2016, 10:02 PM - 1 Like   #18
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What a load of hooey.

We stop down to f/22 and beyond to maximise depth of field and/or allow longer shutter speeds. As long as you understand you will lose some resolution from the best the lens can produce and can accept it, everything is right with the world.

We shoot lenses wide open to get an acceptable shutter speed to counter movement in poor light, or to minimise depth of field, or to elicit the specific properties of that lens' wide open bokeh. As long as we accept the result may not be as sharp in the focal plane as it might have been at the optimal aperture and can accept it, everything is right with the world. Mind you, some lenses are actually designed to be optimally sharp wide open or very close to it.

That might not be the whole story, because I can't be bothered thinking about it any longer. Going for popcorn....
04-24-2016, 11:13 PM   #19
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Great post OP. Fresh reminder to all of us who think cautiously. A bee's dick of difference is but a small thing to worry oneself over. :P

04-24-2016, 11:42 PM   #20
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QuoteOriginally posted by bxf Quote
if you can tolerate the IQ wide open, then you should be able to accept the IQ at smaller apertures, even given the resulting diffraction effects.
Yes.
04-24-2016, 11:59 PM   #21
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Photography is about a lot more than resolution.
04-25-2016, 12:03 AM - 1 Like   #22
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We can go further, Photography has practically nothing to do with resolution.
04-25-2016, 01:24 AM   #23
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Like Rondec, I prefer the f/2-8 range with my sharpest large aperture lenses. For the others less sharp lenses like the versatile DA18-135WR I prefer f/5,6-11. But if I want/need to push it I don’t hesitate to use f/22 or the largest aperture. The reasons for pushing it to the largest aperture is very different from the reasons to pushing it the other way. I tend to come up in situations for pushing it to the largest aperture more often then pushing it the other way. I have even tried to push it to f/45 in extreme cases but have yet to get a successful image at that aperture so I have given up to try.


Last edited by Simen1; 04-25-2016 at 01:34 AM.
04-25-2016, 01:28 AM   #24
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QuoteOriginally posted by Giklab Quote
I'm not sure how many people you've planned to offend, but that was a strong effort.
Funny comment, but it is true that the so-called "holy grail" lenses of extremely large aperture often require stopping down a bit due to softness wide-open. Going to the other extreme end while risking diffraction may be another story entirely. For me, each lens has its sweet-spot and you just have to experiment and find it. Shooting wide-open on expensive glass requires skill and technique but does indeed have desireable advantages. If in doubt, F8 and figure it out!
04-25-2016, 06:31 PM   #25
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Nice bit of humour OP seems to have gone over a few heads :-)
04-26-2016, 10:37 AM   #26
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QuoteOriginally posted by Transit Quote
Nice bit of humour OP seems to have gone over a few heads :-)
Although the OP was written with wit, sarcasm, and in a humorous way, I'm not so sure most responses took the core message as a joke. Personally I agree that individual lenses have their own idiosyncracies, but the light diffraction as it pertains to lenses and apertures has a general and very real effect that in my experience, does not behave in the way the OP described.

I am not a pixel peeper, but when I enlarge my prints to A3+ (13x19") or 16x20" or larger, my desire for great depth-of-field with the use of a small aperture will visibly suffer lens diffraction. And although different lenses are affected more of less, in general one has to pick their poison regarding less resolution+shallow DOF vs. less res+great DOF+max diffraction vs. max res+medium DOF.
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