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08-02-2013, 09:05 PM   #1
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What's the point of f/22?

I have read over and over again that overly small apertures like f/22, f/16, etc cause IQ to go down due to light diffraction. Ever DoF calculator I have seen shows the DoF going down at around f/11-ish depending on the focal length. The "ideal" is f/5.6 to f/8.

If f/22 is so bad then why is available on so many lenses? Is there a time when I would want to use f/22?


08-02-2013, 09:43 PM   #2
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For macro photography sometimes you simply have to bite the bullet and use f/32 or even f/48 - Diffraction is an issue, yes. But sometimes getting the shot is more important. TS-E lenses reduce the need of small f stops due to the scheimpflug effect - but for SLR cameras these are expensive lenses, and there isn't much variation in terms of focal length or aperture speeds with TS-E lenses.

With large format you can exploit the scheimpflug effect with practically any lens*. With a medium format digital back sensor which is typically smaller than a 4X5 negative you can get away with some pretty insane camera movements - this is why large format will always have an edge over smaller formats the inherent flexibility delivered through simplicity.

Bear in mind these are 100% crops from a Pentax K5IIs

As the actor Michael Caine once said " you eventually get to the point where you have to say f*ck it, I don't care! and just get the job done"

*though the Imaging circle projected by the lens does restrain the use of tilts/shifts.

Last edited by Digitalis; 08-04-2013 at 01:53 AM.
08-02-2013, 09:48 PM   #3

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& they can always provide the smallest aperture as it doesn't cost extra and extra brownie points for the marketing literature
08-02-2013, 10:04 PM   #4
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Or . . . you may not have an ND filter when you really need a slow shutter speed. And f 1.2 isn't all that impressive compared to the "sweet spot" either.

Both ends of the aperture scale serve to fill esthetic or "mission" tasks other than the absolute best sharpness possible from the lens.


08-02-2013, 10:22 PM   #5

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f22 is still sharp enough. It's quite common in landscape.
08-03-2013, 01:58 AM   #6
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Also keep in mind that diffraction sets in earlier on small, high-MP sensors. On some cameras, f22 is terrible, on others, its quite good.
And btw, Ive kind of stopped trusting DoF calculators for critical info. They give you a ballpark idea, but you need to test it yourself to decide what is acceptable and what isnt.
08-03-2013, 02:24 AM - 3 Likes   #7

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Here's f22

08-03-2013, 02:56 AM   #8
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Also f22 is needed when you want to produce a star from pointed high light, like sunset/sunrise star... or like this:

08-03-2013, 04:03 AM   #9
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The big reason to use smaller apertures (smaller than f8) is if you want more in focus than what you can wider -- for example if you are shooting a landscape and there is something close in the foreground you want in focus at the same time as you want everything else in focus. The other time is if you want a longer shutter speed in decent light and you don't have an ND filter with you.
08-03-2013, 04:07 AM   #10
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I try to use middle apertures as most lenses are optimized for those. However
in a pinch small apertures can help you get the shot you might otherwise miss.

f/22 or f/32 can get you some depth of field when required with a long lens.
Using film cameras f/22 or f/32 can be handy when you don't have a ND filter.

08-03-2013, 05:23 AM   #11
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Smaller apertures can also help "overpower" the sun when using speedlights to shoot outdoor portraits.
08-03-2013, 05:34 AM   #12
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QuoteOriginally posted by dtmateojr Quote
Here's f22
Awesome shots there! :-)
08-03-2013, 05:54 AM - 1 Like   #13

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Sigma 105 macro at f/22.
Sometimes for macro I never can get above f/11

Last edited by wildman; 09-15-2013 at 06:21 AM.
08-03-2013, 10:20 PM   #14
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Nice shots! I stand before the forum humbled.
08-04-2013, 01:23 AM   #15
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QuoteOriginally posted by Digitalis Quote
"you eventually get to the point where you have to say f*ck it, and just get the job done"
I never heard that said before, what a belter of a quote.

I hope that before my times up, I can come up with some pithy quote that I will be remembered by.

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