JohnSwanda Loc: San Francisco

I shoot flower closeups with a Micro Nikkor 105mm f2.8. It goes to f40. I often use up to f32. I have done tests at f8 to compare, and there just isn't enough DOF. Not just how much is actually in focus at f32, but the out of focus areas are closer to being in focus and more recognizable. I have no interest in focus stacking. At f32 I do notice a little softness in the in focus areas, but a little sharpening fixes that.

burkphoto Loc: High Point, NC

HJ sold our Division to Lifetouch in 2011. The rest of HJ merged with another company a few years later. Lifetouch sold to Shutterfly after that.

MJPerini

First, Diffraction is a real physical phenomenon
Its effect is greater on smaller sensors than larger ones
If you look at the graphs above, focus on the left column the difference between f/4 and f/16 is only 100 points 2720 to 2620. most people could not see that difference.
The second graph the difference is 3150 -2850 or 300, a larger but still small difference for normal pictures.
So for all commonly used apertures it is not a big deal with that lens on FF
In my experience that generally holds true.
The quality difference in dynamic range between base ISO and iso 3200 probably has a larger effect on quality.
But sometimes we need iso 3200 and sometimes we need f/16.
Now diffraction is real but I cannot remember the last time I shot something at f/ 22.
I shoot FF, my wife shoots aps-c and we can see diffraction's effects easily at f/22 and a bit at f/16
So I suspect that is why the advice is given not to worry about it too much.
If I were shooting resolution charts I'd probably be at f5.6-8 at base iso
But mostly I don't do that, and I get lots of critically sharp pictures.
That's probably why Mr. Peterson doesn't worry about it too much.
I'd say whatever format you shoot, do some tests with your own lenses on real subjects.
Also remember that diffraction degrades sharpness relative to the overall sharpness available. The better the lens the less noticeable it will be.
With all the emphasis on fast sharp lenses, and the further improvements in lens design that mirrorless cameras have allowed, the only time anyone is using f/11 f/16 or beyond is because they have a specific reason.
So the advice 'understand it but don't worry about it too much seems prudent to me.

flyboy61 Loc: The Great American Desert

Exactly! On pp. 48-49 of Peterson's UNDERSTANDING EXPOSURE, 3rd Edition, he does comparisons that show diffraction is not a real-world problem. Unless we make it so...sort of like the endless discussions of Bokeh and "noise". Using f/11, 16, or 22 is not harmful to your health or photos!
Fuzzy photeaux are often blamed on "diffraction", when in reality, it is more likely poor technique, like mashing the shutter release like you were smooshing a particularly ugly bug!

camerapapi Loc: Miami, Fl.

This is an interesting post because photographers have been talking about diffraction for ages. What I am going to say is based on my own experience of many years photographing, I am sure others have similar experiences.

When I have used a macro lens I have often being at f22. When shooting landscapes I most often have been at f16. I have been satisfied with the sharpness, I am not a pixel peeper. I use Olympus M43 mirrorless system and in many occasions I have shot at f16 with excellent results. There was some softness in the original file? According to the laws of diffraction most probably there was softness, which I did not see but nothing that could not be improved adding some sharpness in post. Derek Forss, the British photographer, usually shoots landscapes at f16 with his Olympus camera. I have seen his images and I have seen no issues with them.

With my dSLR Nikons I am at f16 very often when shooting landscapes and no issues with those files either. If there is diffraction my eyes have not seen it. It has never been a concern for me to shoot at f16, with mirrorless or with dSLR cameras and I did it often when using film. I agree with Peterson when he has said that "if you need to use f16 or f22 go ahead and forget about diffraction."

tcthome Loc: NJ

As I'm reading this & Dirtfarmer's reply above, I'm thinking, most of the time you would need to be PIXEL PEEPING in order to see it. Maybe really large prints & macro photos.

rehess Loc: South Bend, Indiana, USA

When I photograph with my film camera {I guess that should count as ‘full frame}, I tend to use F/16 and don’t notice ‘a problem’

imagemeister Loc: mid east Florida

Yes, less noticeable with films over 100 ASA.....

I believe it is worth noting that the DIRECT cause of diffraction is the absolute size of the aperture. When we start speaking of f-stops, then it becomes a factor of lens focal length and when we talk lens focal length that brings , by extension, sensor size for a given FOV into consideration.

petrochemist Loc: UK

That would depend on the film camera. Normal 35mm SLRs/rangefinders would be FF, but some would be half frame (getting twice as many shots on a roll)
My auto 110 camera (a 110 film SLR) has a similar sensor size to MFT (2x crop)
my 5x4 monorails have a crop of about x0.43

I have other film cameras with something like 7 other crop factors within this range & I know of others taking the range further out.

larryepage Loc: North Texas area

There are photographers on this forum taking all kinds of photographs destined for all kinds of final uses. There is no question that there are probably some types of photographs being used in some ways where diffraction effects can be a problem. There is no doubt that there are some sorts of photographs used in some other ways in which any of a number of other shortcomings can become some sort of problem.

The trouble I have with photography (really with photographers) is the apparent push for everyone's favorite area of concern to be made everyone's area of concern. The unavoidable result of that is a paranoia that actually makes it impisdible to produce an "acceptable" photograph. As a hobbyyist, it steals at least most of the fun from what is supposed to be an enjoyable and rewarding avocation and replaces it with a never-ending pursuit of a non-attainable goal.

I decided quite a while ago to refuse to play that game. I am not a working photographer, and I am not seeking to be one. I really don't seek to look like one, either. I no longer enter contests in which uninformed judges remind me that I'm not one, and the last thing I want is for someone to think I might be one. And I have little interest in finding myself standing next to someone using the same camera or lens or whatever.

My goal is to take nice images that perhaps also capture the interest of friends and maybe sometimes relatives. Especially if they reveal something that is ordinarily difficult to see. And maybe to help a few others do the same thing.

So if I sometimes strike you as being a little bit out of tune, thank you for noticing. Go have some fun making photographs.

Rab-Eye Loc: Indiana

Interesting discussion. Thank you all for weighing in.

burkphoto Loc: High Point, NC

While I have seen f/22 absolutely RUIN scenes on Micro 4/3, and f/32 ruin scenes on APS-C Canons, my early training as a photojournalist always kicks in to say, "Get the moment, no matter what." As photographers, we have to make intelligent compromises to get what we want. If that means using small apertures to maximize Depth of Field or get star effects on specular reflections, okay. If it means using F/22 to create a fuzzy dream world portrait, so be it.

In most situations, however, I will use a depth of field calculator (DOFC on my iPhone and M1 Mac) to plug in distance, f/stop, focal length, and camera, and get out the near focus point and far focus point. This is all based on 8x10 prints viewed from 13 to 19 inches, but it turns out that an 8x10 is the print size that gives us a "full visual field" reference at that viewing distance. When larger prints are viewed from their diagonal distance, the depth of field calculation will still be accurate.

When using a DOF calculator, you learn pretty quickly, and internalize, the relationships among focal length, field of view, format size, aperture, focal point, and how they affect reasonable depth of field.

Using DOFC is a pre-meditated sort of thing. If I'm photographing large groups of people, then I'm going to do plenty of pre-planning. If I'm photographing a landscape, I'm going to take my time in most cases. If I'm doing macro work, it's deliberate. So I whip out the smartphone and plug in the numbers.

In most cases, it is not necessary to use small apertures with Micro 4/3. It is easier to get MORE depth of field than you want by stopping down. Let's say I'm making a head-and-shoulders individual portrait. I would commonly use a 42.5mm lens (85mm full frame equivalent). If I focus on the subject's eyes at seven feet, then at f/8, everything from 6.16 feet to 8.1 feet will be reasonably sharp. In other words, virtually the entire depth of the body will be sharp. For some portraits, that's TOO MUCH depth of field. For most, it's right for my taste. But if I'm going for a dreamier look with a very out-of-focus background, I can open up to f/4 and the depth of field shrinks down to 6.55 feet to 7.51 feet. The back shoulder of the subject may be a little soft, but the background will be much softer.

For a landscape scene where I want nearly everything sharp, I can use a 20mm setting on my zoom, for a near-normal (40mm full frame equivalence) perspective. If I focus at 11.5 feet, then at f/8, everything from six feet to infinity will be sharp.

Many folks fall back on, "Use f/16," for the same reason Kodak fell back on using a small aperture in their early box cameras. They used a small aperture to keep everything in focus from six feet to infinity, so they could minimize customer complaints about out of focus pictures! To a well-equipped, knowledgeable, and experienced photographer, that is just laziness. There is no need to make unnecessary compromises when you have the right information.

When you NEED the smallest aperture on your lens, use it. In the landscape scenario I mentioned above, stopping down to f/16 and focusing at six feet would only get me an extra three feet of near depth of field. I would almost never want or need that! Your results will vary — with focal length, format size, and other circumstances. I urge those of you with smartphones, tablets, and laptops: get a depth of field calculator and play around with it. Then make some tests to verify you like the results for the kind of subjects YOU photograph.

imagemeister Loc: mid east Florida

In most cases, I can recommend trying to focus at a hyper-focal distance to minimize having to stop down for DOF. If your subject is stationary, you may also try focusing slightly on either side of the hyper-focal distance to see which one you like better in post.

burkphoto Loc: High Point, NC

Using DOFC will always show the hyperfocal distance. However, setting it is difficult with some modern lenses, since they don’t include a distance scale.

TriX Loc: Raleigh, NC

Well said.