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08-10-2016, 12:55 AM   #31
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You shouldn't be shooting at f/22 anyway. Or f/16 if you can help it...

Chris

08-11-2016, 02:32 AM   #32
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QuoteOriginally posted by ChrisPlatt Quote
You shouldn't be shooting at f/22 anyway. Or f/16 if you can help it...

Chris
Really?

Those of us shooting film don't have the freedom to just "turn down the ISO", and we very frequently operate under severe shutter speed restrictions, anywhere between three and four stops compared to our digital bodies. It's easy enough for me to turn my K-5 down to ISO 80 or the shutter speed up to 1/8000, but the vast majority of my film cameras are no faster than 1/1000 and two of them (S1a and SP500) cannot officially even make that. And for those of us who generally make a habit of shooting candidly in lower light (e.g. kids and pets), simply keeping 100-speed film in the camera all the time for sunny days isn't an option either.

Then there is the depth of field requirement for shooting really up-close macro, especially when using multiple extension tubes. Not all of us can afford the time and/or money to indulge in focus stacking, particularly when the things we are photographing are alive and kicking and need ONE shot quickly or they're gone.
08-11-2016, 03:31 AM   #33
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Plenty of cheap F22 glass out there though like the famous Pentax=m 50mm F1.7
08-11-2016, 03:02 PM   #34
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QuoteOriginally posted by pathdoc Quote
Really? etc.

The performance of most lenses is optimal in the middle aperture range.
As you probably know diffraction begins to diminish resolution at small apertures.

When you're up against the high light limit IMO a better choice is to use neutral density filters.
These can help get you back into the "sweet spot".

Chris

08-11-2016, 03:10 PM   #35
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An Bryan Peterson thinks that diffraction isn't that big of a deal. In Exposure Solutions he says just go ahead and shoot at f/22.
08-11-2016, 05:34 PM   #36
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QuoteOriginally posted by boriscleto Quote
An Bryan Peterson thinks that diffraction isn't that big of a deal. In Exposure Solutions he says just go ahead and shoot at f/22.
A lot of lenses are sharper at f22 than they are wide open. I don't see a reason to avoid it if it seems necessary to a picture.
08-12-2016, 01:23 AM   #37
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The reason to avoid them on digital is it bumps up your ISO. I seldom go beyond F8.
08-12-2016, 02:31 AM   #38
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Try shooting a series of photos of an identical composition at all apertures.
When I did this sharpness got progressively worse starting at about f/11.

Diffraction is one of several factors that determine sharpness.
There's an interesting primer on sharpness in film photography here:
http://www.rogerandfrances.com/subscription/ps%20sharpness.html

Diffraction is discussed about halfway down the page.

Chris

08-12-2016, 08:06 AM - 1 Like   #39
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Test of the vintage XR Rikenon 1:2 50 mm at coffee time today.
The Pentax K-01 was locked on a heavy Slik 700 tripod
and focussed as best on the crooked light pole about 10 metre away.

This test, I think, shows the compromise we sometimes need to make, between diffraction
( which is clearly vislble on the green street sign on the f/16)
and depth of field

at f/16 (min ap)
https://app.box.com/s/6p5mo9w4rfgy8foigob1gfb123i0ysle

at f/8
https://app.box.com/s/832pskqnr0d9zlbahrsk21jtaemvz78b

at f/2 (wide open)
https://app.box.com/s/oob7g58l159v12l9c9b2a23vyyw3o916
08-12-2016, 08:54 AM   #40
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QuoteOriginally posted by ChrisPlatt Quote
Diffraction is discussed about halfway down the page.
I guess then it all depends on how big the negative is, how big you intend your print to be, and the IQ/resolution you demand of the image, doesn't it? Sometimes light and/or depth of field are simply the dominant factors, and that's all there is to it.
08-12-2016, 10:15 AM   #41
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It depends on pixel size. Smaller pixels, faster diffraction. The K-3 is more sensitive to diffraction than the K-1
08-12-2016, 03:19 PM - 1 Like   #42
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What 35mm photographer hasn't resorted to f/16, f/22 and even f/32?
In a pinch I've done so, but on close examination quality suffers.

Further for shooting at normal magnifications I'm not real fond of the "pan focus" effect.
This reminds me too much of a photo from a small sensor digital, or some old Chinese print.
IMO selective focus is 35mm's "killer app" and no doubt contributed to the rise of the SLR and fast lenses.

For too fast film in bright light ND filters are a simple way to get back to your best performing apertures.

Chris
08-13-2016, 03:24 AM   #43
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I invite you, then, to pitch a range of lenses that does not close down past f/11 and see what sort of sales response it would get.
08-15-2016, 08:08 AM   #44
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I have witnessed my wife shoot her K1000 at 1/8th second *handheld*.
If she gets the shot she's happy. Who am I to argue?

Chris
08-16-2016, 11:16 AM   #45
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QuoteOriginally posted by ChrisPlatt Quote
I have witnessed my wife shoot her K1000 at 1/8th second *handheld*.
If she gets the shot she's happy. Who am I to argue?

Chris
When I was in high school and college, I would often dip to 1/15s or 1/8s hand held when covering events for the yearbook or paper. I had a much steadier hand back then.


Steve
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