Focus Beyond Infinity
p.5 #1Focus Beyond Infinity
AmbientMike wrote:
I've read the 50/1.2 Nikkor AIS is sharpest at f/2. Does that mean diffraction sets in by 2.8 and you shouldn't shoot other lenses at 2.8, even, due to diffraction?
Of course, that doesn't make much sense. But its probably about the same thing people are doing acting like there's some law of nature saying a lens can't be best at f/11
You should do more diligent research. The 1.2 Nikkor is a special case, designed for a particular purpose, portraiture at large apertures. This is a good explanation of it's characteristics especially related to digital sensors rather than film for which it was designed.
https://photographylife.com/reviews/nikon-noct-nikkor-58mm-f1-2/2
Diffraction is a physical issue caused by the size of the aperture at small diameters, I assume you know that and are choosing to ignore it
I have another lens where sharpnessdrops off before the point where diffraction affects it, Nikkor 35,, f/1.8 for aps-c, cheap optical design being the likely reason for that.
Gerry
I've read the 50/1.2 Nikkor AIS is sharpest at f/2. Does that mean diffraction sets in by 2.8 and you shouldn't shoot other lenses at 2.8, even, due to diffraction?
Of course, that doesn't make much sense. But its probably about the same thing people are doing acting like there's some law of nature saying a lens can't be best at f/11
You should do more diligent research. The 1.2 Nikkor is a special case, designed for a particular purpose, portraiture at large apertures. This is a good explanation of it's characteristics especially related to digital sensors rather than film for which it was designed.
https://photographylife.com/reviews/nikon-noct-nikkor-58mm-f1-2/2
Diffraction is a physical issue caused by the size of the aperture at small diameters, I assume you know that and are choosing to ignore it
I have another lens where sharpnessdrops off before the point where diffraction affects it, Nikkor 35,, f/1.8 for aps-c, cheap optical design being the likely reason for that.
Gerry
Jan 11, 2026 at 03:45 AM
p.5 #2Focus Beyond Infinity
FTR, the 50/1.2 Nikkor and 58/1.2 Noct are two completely different animals. FWIW.
Jan 11, 2026 at 09:16 AM
p.5 #3Focus Beyond Infinity
ruthenium wrote:
Regarding diffraction, this is part of the photographic equivalence considerations. Basically, the onset of diffraction is detectable in equivalent images at equivalent apertures. In my experience, and I believe in the experience of others, the onset of diffraction is seen at f8 with FF cameras. Thus the onset of diffraction should be expected at f4 with micro-four-thirds cameras, or f10 with my GFX100S II.
The concept is fairly simple, but the application to actual photography is more complex and layered.
There’s a simple definition of where it “begins” — beyond the so-called “diffraction-limited aperture.” At that point, the sensor would theoretically be capable of registering details beyond what the lens can provide. (In the opposite direction from that point, towards even larger apertures, the potential image detail would be limited by sensor resolution rather than the lens.)
Some misinterpret this to assume that the “sharpest aperture” is at this diffraction-limited point. But it isn’t quite that simple. For example, it is entirely possible that the lens you are using might get a bit sharper in the corners as you stop down, so if you are looking at overall image sharpness, basing everything on the diffraction limited aperture might lead you in the wrong direction. Even more important, there are creative/aesthetic choices that will inevitably lead you away from this supposedly sharpest aperture… and your photograph will look “better” and even potentially impress viewers as being subjectively sharper at other apertures.
The absolute “size” of the diffraction blur (if you were to measure it with an imaginary ruler) is the same at a given aperture regardless of the format. So why would you worry about it at f/11 on one format and not on another? The size of the blur relative to the overall image witdth is “larger” as a percentage of a smaller frame.
Finally, it is possible to obsess over the “perfect” aperture, and we see plenty of that in photography forums. Better to become personally acquainted with the actual visual effect of different apertures on real world images using your own gear. Yes, f/8 on some high resolution FF camera does decrease images sharpness slightly… but when you make a print of that f/8 image, even at a vary large size, it can look extremely sharp — in other words, the diffraction blur wasn’t actually visible or relevant.
That’s why I’ll use f/16 or sometimes f/22 on a full frame system, depending on the subject and the way I’m phoographing it. Or why I might use f/1.4. Technically, the sharpest points in the frame will be less sharp than they might have been at the diffraction-limited aperture, but the photographs is better when we sacrifice a bit of theoretical maximum sharpness for more or less DOF and so on.
Regarding diffraction, this is part of the photographic equivalence considerations. Basically, the onset of diffraction is detectable in equivalent images at equivalent apertures. In my experience, and I believe in the experience of others, the onset of diffraction is seen at f8 with FF cameras. Thus the onset of diffraction should be expected at f4 with micro-four-thirds cameras, or f10 with my GFX100S II.
The concept is fairly simple, but the application to actual photography is more complex and layered.
There’s a simple definition of where it “begins” — beyond the so-called “diffraction-limited aperture.” At that point, the sensor would theoretically be capable of registering details beyond what the lens can provide. (In the opposite direction from that point, towards even larger apertures, the potential image detail would be limited by sensor resolution rather than the lens.)
Some misinterpret this to assume that the “sharpest aperture” is at this diffraction-limited point. But it isn’t quite that simple. For example, it is entirely possible that the lens you are using might get a bit sharper in the corners as you stop down, so if you are looking at overall image sharpness, basing everything on the diffraction limited aperture might lead you in the wrong direction. Even more important, there are creative/aesthetic choices that will inevitably lead you away from this supposedly sharpest aperture… and your photograph will look “better” and even potentially impress viewers as being subjectively sharper at other apertures.
The absolute “size” of the diffraction blur (if you were to measure it with an imaginary ruler) is the same at a given aperture regardless of the format. So why would you worry about it at f/11 on one format and not on another? The size of the blur relative to the overall image witdth is “larger” as a percentage of a smaller frame.
Finally, it is possible to obsess over the “perfect” aperture, and we see plenty of that in photography forums. Better to become personally acquainted with the actual visual effect of different apertures on real world images using your own gear. Yes, f/8 on some high resolution FF camera does decrease images sharpness slightly… but when you make a print of that f/8 image, even at a vary large size, it can look extremely sharp — in other words, the diffraction blur wasn’t actually visible or relevant.
That’s why I’ll use f/16 or sometimes f/22 on a full frame system, depending on the subject and the way I’m phoographing it. Or why I might use f/1.4. Technically, the sharpest points in the frame will be less sharp than they might have been at the diffraction-limited aperture, but the photographs is better when we sacrifice a bit of theoretical maximum sharpness for more or less DOF and so on.
Jan 11, 2026 at 09:20 AM
AmbientMike
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p.5 #4Focus Beyond Infinity
gyoung143 wrote:
AmbientMike wrote
I've read the 50/1.2 Nikkor AIS is sharpest at f/2. Does that mean diffraction sets in by 2.8 and you shouldn't shoot other lenses at 2.8, even, due to diffraction?Of course, that doesn't make much sense. But its probably about the same thing people are doing acting like there's some law of nature saying a lens can't be best at f/11
https://photographylife.com/reviews/nikon-noct-nikkor-58mm-f1-2/2
Diffraction is a physical issue caused by the size of the aperture at small diameters, I assume you know that and are choosing to ignore it
I have another lens where sharpnessdrops off before the point where diffraction affects it, Nikkor 35,, f/1.8 for aps-c, cheap optical design being the likely reason for that.
Gerry
Why dont you tell me to do more diligent research then start talking about the wrong lens. Good job.
Jan 11, 2026 at 09:58 AM
AmbientMike
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p.5 #5Focus Beyond Infinity
Diffraction is the Double Slit experiment. Good luck relating that to lens sharpness. The wikipedia page on diffraction didn't use to have anything easily relatable to lens sharpness, I pointed this out and whether a lens company has a wikipedia account and changed this after seeing my post, idk, it does now
Adaptall-2.com has MP numbers on the 80-200/2.8, it gets its best contrast readings at f/11 at all 3 settings. At 80mm its still getting 62lp/mn at f/16, its still only down to 56lp/mm from a high of 63lp/mm at 135mm (an excellent result) at f/22!! People today think they can't get excellent results past 5.6 because the lenses often top out there, and that theres a law of nature saying so, it's pretty ridiculous imo
Adaptall-2.com has MP numbers on the 80-200/2.8, it gets its best contrast readings at f/11 at all 3 settings. At 80mm its still getting 62lp/mn at f/16, its still only down to 56lp/mm from a high of 63lp/mm at 135mm (an excellent result) at f/22!! People today think they can't get excellent results past 5.6 because the lenses often top out there, and that theres a law of nature saying so, it's pretty ridiculous imo
Jan 11, 2026 at 10:10 AM
p.5 #6Focus Beyond Infinity
gdanmitchell wrote:
The concept is fairly simple, but the application to actual photography is more complex and layered.
There’s a simple definition of where it “begins” — beyond the so-called “diffraction-limited aperture.” At that point, the sensor would theoretically be capable of registering details beyond what the lens can provide. (In the opposite direction from that point, towards even larger apertures, the potential image detail would be limited by sensor resolution rather than the lens.)
Some misinterpret this to assume that the “sharpest aperture” is at this diffraction-limited point. But it isn’t quite that simple. For example, it is entirely possible that the lens...Show more →
Dan, diffraction is one of many considerations in photography - far from being the top consideration. I expect very few photographers are obsessed about diffraction.
Changing the aperture is a 100% practical decision, as you correctly noted. The problem is that an average photographer is guided by experience and intuition, but they are very rarely guided by exact knowledge. Jack Hogan actually studied the effects of changing the aperture in three different scenarios. The reason he came to the conclusion that "for me, it seems that I will no longer be stopping down past f/11" was that he found no benefit to this. I am inclined to believe him.
When you say "I'll use f/16 or sometimes f/22 on a full frame system" - my immediate question and concern is whether you BELIEVE that this should improve the image (vs. f/11 or f/8, for example), or you have carefully tested the outcomes and can prove this with the images to show me that your strategy actually works better? This is not a personal comment in any way. The modern world is drowning in misinformation and misunderstandings, and my belief is that 99.999% of photographers may believe in something about photography that is verifiably not correct. Like you already mentioned this about what some believe about diffraction on micro-four-thirds systems. Similarly, I confidently expect that too many photographers genuinely believe that an f/2.8 lens is as "fast" on FF as in front of a sensor of a different size - just to give an example.
Some photographers tend to be more interested in an in-depth understanding of the technology. Others dismiss this interest entirely as useless, and take pride in the wealth of their practical knowledge and experience. It makes sense to respect both groups and listen to both groups, however, ultimately we need to be aware of the fact that the field of photography is full of misconcepts, myths. and ideas not rooted in science.
My main concern about closing the aperture is the about the loss of light, more than about the effect of diffraction. Unlike the "proper" landscape photographers who shoot from a tripod, I almost always shoot hand-held. Thus, retaining a reasonable shutter speed at the base ISO, or as close to the base ISO as the circumstances permit, is one of my usual top technical considerations (outside of the composition).
ruthenium wrote
Regarding diffraction, this is part of the photographic equivalence considerations. Basically, the onset of diffraction is detectable in equivalent images at equivalent apertures. In my experience, and I believe in the experience of others, the onset of diffraction is seen at f8 with FF cameras. Thus the onset of diffraction should be expected at f4 with micro-four-thirds cameras, or f10 with my GFX100S II.There’s a simple definition of where it “begins” — beyond the so-called “diffraction-limited aperture.” At that point, the sensor would theoretically be capable of registering details beyond what the lens can provide. (In the opposite direction from that point, towards even larger apertures, the potential image detail would be limited by sensor resolution rather than the lens.)
Some misinterpret this to assume that the “sharpest aperture” is at this diffraction-limited point. But it isn’t quite that simple. For example, it is entirely possible that the lens...Show more →
Dan, diffraction is one of many considerations in photography - far from being the top consideration. I expect very few photographers are obsessed about diffraction.
Changing the aperture is a 100% practical decision, as you correctly noted. The problem is that an average photographer is guided by experience and intuition, but they are very rarely guided by exact knowledge. Jack Hogan actually studied the effects of changing the aperture in three different scenarios. The reason he came to the conclusion that "for me, it seems that I will no longer be stopping down past f/11" was that he found no benefit to this. I am inclined to believe him.
When you say "I'll use f/16 or sometimes f/22 on a full frame system" - my immediate question and concern is whether you BELIEVE that this should improve the image (vs. f/11 or f/8, for example), or you have carefully tested the outcomes and can prove this with the images to show me that your strategy actually works better? This is not a personal comment in any way. The modern world is drowning in misinformation and misunderstandings, and my belief is that 99.999% of photographers may believe in something about photography that is verifiably not correct. Like you already mentioned this about what some believe about diffraction on micro-four-thirds systems. Similarly, I confidently expect that too many photographers genuinely believe that an f/2.8 lens is as "fast" on FF as in front of a sensor of a different size - just to give an example.
Some photographers tend to be more interested in an in-depth understanding of the technology. Others dismiss this interest entirely as useless, and take pride in the wealth of their practical knowledge and experience. It makes sense to respect both groups and listen to both groups, however, ultimately we need to be aware of the fact that the field of photography is full of misconcepts, myths. and ideas not rooted in science.
My main concern about closing the aperture is the about the loss of light, more than about the effect of diffraction. Unlike the "proper" landscape photographers who shoot from a tripod, I almost always shoot hand-held. Thus, retaining a reasonable shutter speed at the base ISO, or as close to the base ISO as the circumstances permit, is one of my usual top technical considerations (outside of the composition).
Jan 11, 2026 at 11:49 AM
p.5 #7Focus Beyond Infinity
Jack Flesher wrote:
FTR, the 50/1.2 Nikkor and 58/1.2 Noct are two completely different animals. FWIW.
Apologies for confusing the two
But this test of the 50mm also does not show it as 'best at 2.8' but classically improves overall (for sharpness) until much closer to where diffraction sets in
https://photographylife.com/reviews/nikon-50mm-f1-2-ai-s/2
Again, a specialist lens fir use at large apertures. No one would seriously choose to use either for distant landscapes at f/8 never mind smaller.
Gerry
Jan 11, 2026 at 12:00 PM
p.5 #8Focus Beyond Infinity
ruthenium wrote:
The concept is fairly simple, but the application to actual photography is more complex and layered.
There’s a simple definition of where it “begins” — beyond the so-called “diffraction-limited aperture.” At that point, the sensor would theoretically be capable of registering details beyond what the lens can provide. (In the opposite direction from that point, towards even larger apertures, the potential image detail would be limited by sensor resolution rather than the lens.)
Some misinterpret this to assume that the “sharpest aperture” is at this diffraction-limited point. But it isn’t quite that simple. For example, it is entirely possible that the lens you are using might get a bit sharper in the corners as you stop down, so if you are looking at overall image sharpness, basing everything on the diffraction limited aperture might lead you in the wrong direction. Even more important, there are creative/aesthetic choices that will inevitably lead you away from this supposedly sharpest aperture… and your photograph will look “better” and even potentially impress viewers as being subjectively sharper at other apertures.
The absolute “size” of the diffraction blur (if you were to measure it with an imaginary ruler) is the same at a given aperture regardless of the format. So why would you worry about it at f/11 on one format and not on another? The size of the blur relative to the overall image witdth is “larger” as a percentage of a smaller frame.
Finally, it is possible to obsess over the “perfect” aperture, and we see plenty of that in photography forums. Better to become personally acquainted with the actual visual effect of different apertures on real world images using your own gear. Yes, f/8 on some high resolution FF camera does decrease images sharpness slightly… but when you make a print of that f/8 image, even at a vary large size, it can look extremely sharp — in other words, the diffraction blur wasn’t actually visible or relevant.
That’s why I’ll use f/16 or sometimes f/22 on a full frame system, depending on the subject and the way I’m phoographing it. Or why I might use f/1.4. Technically, the sharpest points in the frame will be less sharp than they might have been at the diffraction-limited aperture, but the photographs is better when we sacrifice a bit of theoretical maximum sharpness for more or less DOF and so on.Dan, diffraction is one of many considerations in photography - far from being the top consideration. I expect very few photographers are obsessed about diffraction.
Changing the aperture is a 100% practical decision, as you correctly noted. The problem is that an average photographer is guided by experience and intuition, but they are very rarely guided by exact knowledge. Jack Hogan actually studied the effects of changing the aperture in three different scenarios. The reason he came to the conclusion that "for me, it seems that I will no longer be stopping down past f/11" was that he found no...Show more →
I’m fortunate enough to have a 44” printer, so I can test and have tested plenty of large prints against the theories. It also helps to have viewed a whole lot of great photographic prints by a whole lot of great (as in “they are in galleries and museums”) photographers over the years. The fact is that that tiny final increment of sharpness that some are looking for turns out to matter a lot less than they expect.
(I encourage people to actually to to an exhibit and look at the prints of photographs that you regard as great, and to do so as closely as you possibly can. You’ll virtually always find that they don’t have the “pin sharp at any size” qualty that folks imagine they’ll have. I recall seeing this years ago in Ansel Adams prints. I really recall “getting it” at a SFMoMA exhibit of the gigantic prints of Jeff Wall — they are stunning when viewed as we normally do, but if you get nose-length close… Same with the famous Avedon “American West” portraits, which I’ve seen in person a couple of times — utterly stunning, huge prints…)
My point is not that diffraction has no effect on the sharpness of photographs at f/16, for example. Objectively speaking, it absolutely must — there’s no getting around that law of optics with the gear we use. However, two other things are also true, and it is critical (and freeing, for those obsessed with “perfect apertures”) to understand them.
1. While, for example, f/11 or f/16 is undoubtedly objectively less sharp than your diffraction-limited aperture, the difference in a real photographic print at size (or an equivalent electronic presentation) is often insignificant or invisible in any way that is meaningful to observers. In many case, if you looked at a crop from a f/8 and a f/16 shot that featured something in the plane of optimal focus, you’d be hard pressed to figure out which is which.
2. In many cases, other needs trump the “best aperture” sharpness. If you need a bit more DOF, it doesn’t mater than stuff in the plane of focus is a tiny bit less sharp — but still very sharp — since you are more concerned with things a little outside that plane. The inverse of that is that f/1.4 or f/1.2 or whatever large aperture you select gains you no sharpness and will likely lose a bit of it for other optical reason… but that the overall result may e better if the use of narrow DOF is important to your photograph.
And, yes, I have very much tested these things. I’ve gone so far as to set a camera on a tripod, prefocus, turn of AF, and do a series of aV mode images at each whole aperture and then compare side-by-side on screen and in prints.
In the end, I operate by those three rules that I listed earlier.
1. If DOF isn’t an issue (I don’t want to narrow or widen it) I’ll just shoot at an aperture that is somewhere in the range of the lens’s best performance and the diffraction-limited aperture because… why not?
2. If I need to limit DOF for creative reasons, I’ll open up as much as I need to in order to get the effect I desire.
3. If I need more DOF I’ll stop down as much as makes sense with the system I’m using and the subject I’m shooting. (If that can’t be achieved by using a small aperture, I’ll resort to focus blending techniques.)
On full frame, my typical default (which varies by lens) is around f/8. On APS-C my default is around f/5.6. On full frame I don’t worry at all about f/11, and I’ll use f/16 if needed without worrying much. On rarer occasions when I maximizing DOF is import and I ma use f/22. On APS-C I move that scale rough aperture larger — e.g. I am fine with f/8, may use f/11 without much concern if I need to, and only rarely use f/16.
One of the great things about digital photography technology is that it is so easy to actually test these things yourself — you don’t have to rely on what what you read or what others tell you. You can listen to them and then test what they say to see if it actually is true, if it makes a difference, and how large that difference is.
I’ll turn your 99.999% of photographers analogy on ts head for a moment. Here’s the danger. After reading a truth (for example, that there’s more diffraction blur at apertures larger than the diffraction-limited aperture), too many people take that one fact and base everything on it while failing to recognize that it is just one data point to consider when making photographs. We see that category of error all the time in photography forums: the person who learns that camera A has more DR than camera B and concludes that Camera A is the best. The person who learns that Camera C has faster burst more than Camera D and decides that Camera C is the best camera. The person who learns that format E can capture more detail than Format F and concludes that Format E is the best format. And on and on — repeat with the system with the “best” noise handling, the best AF, the best “whatever.” It is too easy to let this stuff become both obsessive and one-dimensional.
And, of course, those who decide that photography is all about technical specs and who lose track of what actually makes a photograph great…
gdanmitchell wrote
ruthenium wrote
Regarding diffraction, this is part of the photographic equivalence considerations. Basically, the onset of diffraction is detectable in equivalent images at equivalent apertures. In my experience, and I believe in the experience of others, the onset of diffraction is seen at f8 with FF cameras. Thus the onset of diffraction should be expected at f4 with micro-four-thirds cameras, or f10 with my GFX100S II.There’s a simple definition of where it “begins” — beyond the so-called “diffraction-limited aperture.” At that point, the sensor would theoretically be capable of registering details beyond what the lens can provide. (In the opposite direction from that point, towards even larger apertures, the potential image detail would be limited by sensor resolution rather than the lens.)
Some misinterpret this to assume that the “sharpest aperture” is at this diffraction-limited point. But it isn’t quite that simple. For example, it is entirely possible that the lens you are using might get a bit sharper in the corners as you stop down, so if you are looking at overall image sharpness, basing everything on the diffraction limited aperture might lead you in the wrong direction. Even more important, there are creative/aesthetic choices that will inevitably lead you away from this supposedly sharpest aperture… and your photograph will look “better” and even potentially impress viewers as being subjectively sharper at other apertures.
The absolute “size” of the diffraction blur (if you were to measure it with an imaginary ruler) is the same at a given aperture regardless of the format. So why would you worry about it at f/11 on one format and not on another? The size of the blur relative to the overall image witdth is “larger” as a percentage of a smaller frame.
Finally, it is possible to obsess over the “perfect” aperture, and we see plenty of that in photography forums. Better to become personally acquainted with the actual visual effect of different apertures on real world images using your own gear. Yes, f/8 on some high resolution FF camera does decrease images sharpness slightly… but when you make a print of that f/8 image, even at a vary large size, it can look extremely sharp — in other words, the diffraction blur wasn’t actually visible or relevant.
That’s why I’ll use f/16 or sometimes f/22 on a full frame system, depending on the subject and the way I’m phoographing it. Or why I might use f/1.4. Technically, the sharpest points in the frame will be less sharp than they might have been at the diffraction-limited aperture, but the photographs is better when we sacrifice a bit of theoretical maximum sharpness for more or less DOF and so on.
Changing the aperture is a 100% practical decision, as you correctly noted. The problem is that an average photographer is guided by experience and intuition, but they are very rarely guided by exact knowledge. Jack Hogan actually studied the effects of changing the aperture in three different scenarios. The reason he came to the conclusion that "for me, it seems that I will no longer be stopping down past f/11" was that he found no...Show more →
I’m fortunate enough to have a 44” printer, so I can test and have tested plenty of large prints against the theories. It also helps to have viewed a whole lot of great photographic prints by a whole lot of great (as in “they are in galleries and museums”) photographers over the years. The fact is that that tiny final increment of sharpness that some are looking for turns out to matter a lot less than they expect.
(I encourage people to actually to to an exhibit and look at the prints of photographs that you regard as great, and to do so as closely as you possibly can. You’ll virtually always find that they don’t have the “pin sharp at any size” qualty that folks imagine they’ll have. I recall seeing this years ago in Ansel Adams prints. I really recall “getting it” at a SFMoMA exhibit of the gigantic prints of Jeff Wall — they are stunning when viewed as we normally do, but if you get nose-length close… Same with the famous Avedon “American West” portraits, which I’ve seen in person a couple of times — utterly stunning, huge prints…)
My point is not that diffraction has no effect on the sharpness of photographs at f/16, for example. Objectively speaking, it absolutely must — there’s no getting around that law of optics with the gear we use. However, two other things are also true, and it is critical (and freeing, for those obsessed with “perfect apertures”) to understand them.
1. While, for example, f/11 or f/16 is undoubtedly objectively less sharp than your diffraction-limited aperture, the difference in a real photographic print at size (or an equivalent electronic presentation) is often insignificant or invisible in any way that is meaningful to observers. In many case, if you looked at a crop from a f/8 and a f/16 shot that featured something in the plane of optimal focus, you’d be hard pressed to figure out which is which.
2. In many cases, other needs trump the “best aperture” sharpness. If you need a bit more DOF, it doesn’t mater than stuff in the plane of focus is a tiny bit less sharp — but still very sharp — since you are more concerned with things a little outside that plane. The inverse of that is that f/1.4 or f/1.2 or whatever large aperture you select gains you no sharpness and will likely lose a bit of it for other optical reason… but that the overall result may e better if the use of narrow DOF is important to your photograph.
And, yes, I have very much tested these things. I’ve gone so far as to set a camera on a tripod, prefocus, turn of AF, and do a series of aV mode images at each whole aperture and then compare side-by-side on screen and in prints.
In the end, I operate by those three rules that I listed earlier.
1. If DOF isn’t an issue (I don’t want to narrow or widen it) I’ll just shoot at an aperture that is somewhere in the range of the lens’s best performance and the diffraction-limited aperture because… why not?
2. If I need to limit DOF for creative reasons, I’ll open up as much as I need to in order to get the effect I desire.
3. If I need more DOF I’ll stop down as much as makes sense with the system I’m using and the subject I’m shooting. (If that can’t be achieved by using a small aperture, I’ll resort to focus blending techniques.)
On full frame, my typical default (which varies by lens) is around f/8. On APS-C my default is around f/5.6. On full frame I don’t worry at all about f/11, and I’ll use f/16 if needed without worrying much. On rarer occasions when I maximizing DOF is import and I ma use f/22. On APS-C I move that scale rough aperture larger — e.g. I am fine with f/8, may use f/11 without much concern if I need to, and only rarely use f/16.
One of the great things about digital photography technology is that it is so easy to actually test these things yourself — you don’t have to rely on what what you read or what others tell you. You can listen to them and then test what they say to see if it actually is true, if it makes a difference, and how large that difference is.
I’ll turn your 99.999% of photographers analogy on ts head for a moment. Here’s the danger. After reading a truth (for example, that there’s more diffraction blur at apertures larger than the diffraction-limited aperture), too many people take that one fact and base everything on it while failing to recognize that it is just one data point to consider when making photographs. We see that category of error all the time in photography forums: the person who learns that camera A has more DR than camera B and concludes that Camera A is the best. The person who learns that Camera C has faster burst more than Camera D and decides that Camera C is the best camera. The person who learns that format E can capture more detail than Format F and concludes that Format E is the best format. And on and on — repeat with the system with the “best” noise handling, the best AF, the best “whatever.” It is too easy to let this stuff become both obsessive and one-dimensional.
And, of course, those who decide that photography is all about technical specs and who lose track of what actually makes a photograph great…
Jan 11, 2026 at 12:31 PM
p.5 #9Focus Beyond Infinity
AmbientMike wrote:
I've read the 50/1.2 Nikkor AIS is sharpest at f/2. Does that mean diffraction sets in by 2.8 and you shouldn't shoot other lenses at 2.8, even, due to diffraction?
Diffraction starts at the widest aperture, and increases as you close down the aperture. On the other hand, the effects of many other optical aberrations improve as the aperture is closed down. Lenses become "diffraction limited" at the point where sharpness loss due to diffraction becomes greater than the improvements of the other aberrations gained by stopping down. This is obviously a function of lens design, which is why different lenses show noticeable diffraction effects at different apertures (regardless of camera sensor size).
I've read the 50/1.2 Nikkor AIS is sharpest at f/2. Does that mean diffraction sets in by 2.8 and you shouldn't shoot other lenses at 2.8, even, due to diffraction?
Diffraction starts at the widest aperture, and increases as you close down the aperture. On the other hand, the effects of many other optical aberrations improve as the aperture is closed down. Lenses become "diffraction limited" at the point where sharpness loss due to diffraction becomes greater than the improvements of the other aberrations gained by stopping down. This is obviously a function of lens design, which is why different lenses show noticeable diffraction effects at different apertures (regardless of camera sensor size).
Jan 11, 2026 at 12:57 PM
AmbientMike
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p.5 #10Focus Beyond Infinity
gdanmitchell wrote:
AmbientMike wrote
Mostly the stuff you read about diffraction is bogus imo. Yes, they make lenses that are sharpest by 5.6 these days, honestly thats a bit of a problem though, if you prefer f/8+. Look at adaptall-2.com, they have a bunch of old MP tests, you can find excellent lenses at f/11+.I did a lot of f/16-32 shooting on 12mp m4/3, 48mp FF pixel density. I can't imagine whatever equations they made up say that works. But it does, or it can, given the proper lens
it is an optical phenomenon that affects all lenses, one that is related to focal length and aperture, not to how well the lens is made. Diffraction isn't about the quality of the lens itself. It affects the best lens in the world just as it affects the worst.
It is pretty easy to test for yourself. Take that m2/3 camera and put it on a tripod and manually focus on a clear target. Make test...Show more →
I already tested. You want to preach and say how you just know all these facts and tell me how to test, how did your testing go? Since you know so much.
Jan 11, 2026 at 07:23 PM
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p.5 #11Focus Beyond Infinity
gyoung143 wrote:
Jack Flesher wrote
FTR, the 50/1.2 Nikkor and 58/1.2 Noct are two completely different animals. FWIW.But this test of the 50mm also does not show it as 'best at 2.8' but classically improves overall (for sharpness) until much closer to where diffraction sets in
https://photographylife.com/reviews/nikon-50mm-f1-2-ai-s/2
Again, a specialist lens fir use at large apertures. No one would seriously choose to use either for distant landscapes at f/8 never mind smaller.
Gerry
Congrats on figuring out the correct lens
Jan 11, 2026 at 07:24 PM
p.5 #12Focus Beyond Infinity
There is a whole bunch of misinformation, or perhaps hyperbole in this thread. The fact is that,
1) Diffraction is real and tangible and easily visible with today's higher resolution sensors; physics does not lie. So anybody arguing against it's existence should be taken with a grain of salt. While the effect may not bother THEM, it is visible and bothersome to many of us who have witnessed it ruining our own images.
2) Every lens assembly for imaging can extend beyond infinity focus at normal use temperatures, precisely to accommodate potential thermal expansion in the focus system being used in hot temperatures. This is true regardless of camera design and affects manual or electronic and range-finder, slr or mirrorless.
2a) What is true outside of this fact, is some lenses--and most notably Leica M manual focus lenses--can be adjusted to have a hard stop at infinity, but this will only work precisely at a given, and fairly narrow range of use temperatures. The negative effect of doing this is more prominent in faster and/or longer glass at near infinity distances. Hence users of 35mm f2 lenses may not notice much detriment, while users of 50mm f0.95 or 105mm f1.4 glass most certainly will, even if ambient temperatures are just a few degrees outside the temperature used to set this parameter. The big however is, the thermal offset is further reduced as focus distances shorten up, so is not generally a significant "negative" for lenses primarily used at closer to mid focus distances; and arguably this is how many use their Leica M cameras. Regardless, none of this negates the fact that thermal expansion affects not only infinity focus, but precise focus at all distances in any lens system.
2b) Finally, this argument is effectively rendered moot with on-sensor PDAF combined with ultrasonic or linear AF motors in lenses, since with them we get relatively "instant" accurate focus regardless of ambient temperature; and even while the lenses can technically focus beyond infinity. The big however-but is the folks using said system actually need to understand how to use it properly *for their chosen system*, and therein is where the main problem lies...
/rant
1) Diffraction is real and tangible and easily visible with today's higher resolution sensors; physics does not lie. So anybody arguing against it's existence should be taken with a grain of salt. While the effect may not bother THEM, it is visible and bothersome to many of us who have witnessed it ruining our own images.
2) Every lens assembly for imaging can extend beyond infinity focus at normal use temperatures, precisely to accommodate potential thermal expansion in the focus system being used in hot temperatures. This is true regardless of camera design and affects manual or electronic and range-finder, slr or mirrorless.
2a) What is true outside of this fact, is some lenses--and most notably Leica M manual focus lenses--can be adjusted to have a hard stop at infinity, but this will only work precisely at a given, and fairly narrow range of use temperatures. The negative effect of doing this is more prominent in faster and/or longer glass at near infinity distances. Hence users of 35mm f2 lenses may not notice much detriment, while users of 50mm f0.95 or 105mm f1.4 glass most certainly will, even if ambient temperatures are just a few degrees outside the temperature used to set this parameter. The big however is, the thermal offset is further reduced as focus distances shorten up, so is not generally a significant "negative" for lenses primarily used at closer to mid focus distances; and arguably this is how many use their Leica M cameras. Regardless, none of this negates the fact that thermal expansion affects not only infinity focus, but precise focus at all distances in any lens system.
2b) Finally, this argument is effectively rendered moot with on-sensor PDAF combined with ultrasonic or linear AF motors in lenses, since with them we get relatively "instant" accurate focus regardless of ambient temperature; and even while the lenses can technically focus beyond infinity. The big however-but is the folks using said system actually need to understand how to use it properly *for their chosen system*, and therein is where the main problem lies...
/rant
Jan 12, 2026 at 11:20 AM
p.5 #13Focus Beyond Infinity
gdanmitchell wrote:
(I encourage people to actually to to an exhibit and look at the prints of photographs that you regard as great, and to do so as closely as you possibly can. You’ll virtually always find that they don’t have the “pin sharp at any size” qualty that folks imagine they’ll have. I recall seeing this years ago in Ansel Adams prints. I really recall “getting it” at a SFMoMA exhibit of the gigantic prints of Jeff Wall — they are stunning when viewed as we normally do, but if you get nose-length close… Same with the famous Avedon “American West” portraits,...Show more →
Sharpness was just as important for those photographers, contemporaneously, as it is for us today.
As I'm sure you know, Ansel Adam's prints were enlarged into mural size using sophisticated (and often completely novel) enlargement techniques designed specifically to optimize sharpness. These processes involved hand-washing prints 10-12 times, specially designed enlargement darkrooms, etc. Not to mention artistic instinct regarding what chemicals to use and how long to expose the mural paper to the projection of the enlarged print. Adams was also a master of using four-axis tilt shift on his cameras to achieve essentially infinite focus at f/64 (equivalent to about f/9 on a full frame camera).
So for the time period in which they were made (for Adams, the 1950s-70s, relying on prints from circa 1940), the sharpness and tone of these images was unparalleled.
Adams did expect that his prints would be appreciated at the proper viewing distance, but let's not revise history to make it seem as if sharpness did not matter very much to him and those other photographers. It's just that what could be achieved by the technology was inherently more limited than, in theory, what the best lens, camera, enlargement, and printing of today are collectively able to achieve. At the same time, to one of your other points, Adams was known to reject his own rules when the artistic vision required it.
Edited on Jan 12, 2026 at 01:30 PM · View previous versions
(I encourage people to actually to to an exhibit and look at the prints of photographs that you regard as great, and to do so as closely as you possibly can. You’ll virtually always find that they don’t have the “pin sharp at any size” qualty that folks imagine they’ll have. I recall seeing this years ago in Ansel Adams prints. I really recall “getting it” at a SFMoMA exhibit of the gigantic prints of Jeff Wall — they are stunning when viewed as we normally do, but if you get nose-length close… Same with the famous Avedon “American West” portraits,...Show more →
Sharpness was just as important for those photographers, contemporaneously, as it is for us today.
As I'm sure you know, Ansel Adam's prints were enlarged into mural size using sophisticated (and often completely novel) enlargement techniques designed specifically to optimize sharpness. These processes involved hand-washing prints 10-12 times, specially designed enlargement darkrooms, etc. Not to mention artistic instinct regarding what chemicals to use and how long to expose the mural paper to the projection of the enlarged print. Adams was also a master of using four-axis tilt shift on his cameras to achieve essentially infinite focus at f/64 (equivalent to about f/9 on a full frame camera).
So for the time period in which they were made (for Adams, the 1950s-70s, relying on prints from circa 1940), the sharpness and tone of these images was unparalleled.
Adams did expect that his prints would be appreciated at the proper viewing distance, but let's not revise history to make it seem as if sharpness did not matter very much to him and those other photographers. It's just that what could be achieved by the technology was inherently more limited than, in theory, what the best lens, camera, enlargement, and printing of today are collectively able to achieve. At the same time, to one of your other points, Adams was known to reject his own rules when the artistic vision required it.
Edited on Jan 12, 2026 at 01:30 PM · View previous versions
Jan 12, 2026 at 12:00 PM
AmbientMike
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p.5 #14Focus Beyond Infinity
Here's one I shot at f/32 on m4/3, using a lens thats more ok to good than great at that aperture. Also I have a poster sized print of a Velvia slide at f/32 that turned out really good, printed from a high resolution scan, in the other room.
https://www.fredmiranda.com/forum/topic/1517588/
So no, I'm not interested in hearing about how i'm not supposed to shoot past f/5.6-8, because of the pseudo science of diffraction as practiced on photo forums. Just because your lens got less sharp after its best aperture doesn't mean there's a law of science applying to every lens saying you must use wider apertures. I have a pretty good idea what lenses might, or might not, work at f/16+
https://www.fredmiranda.com/forum/topic/1517588/
So no, I'm not interested in hearing about how i'm not supposed to shoot past f/5.6-8, because of the pseudo science of diffraction as practiced on photo forums. Just because your lens got less sharp after its best aperture doesn't mean there's a law of science applying to every lens saying you must use wider apertures. I have a pretty good idea what lenses might, or might not, work at f/16+
Jan 12, 2026 at 12:19 PM
p.5 #15Focus Beyond Infinity
AmbientMike wrote:
Here's one I shot at f/32 on m4/3, using a lens thats more ok to good than great at that aperture. Also I have a poster sized print of a Velvia slide at f/32 that turned out really good, printed from a high resolution scan, in the other room.
https://www.fredmiranda.com/forum/topic/1517588/
So no, I'm not interested in hearing about how i'm not supposed to shoot past f/5.6-8, because of the pseudo science of diffraction as practiced on photo forums. Just because your lens got less sharp after its best aperture doesn't mean there's a law of science applying to every lens saying you...Show more →
Sorry, they look pretty bad to me even here at the tiny web resolution. Again, if YOU are happy with that look, then so be it. But I can see the loss even in the small samples you posted...
Here's one I shot at f/32 on m4/3, using a lens thats more ok to good than great at that aperture. Also I have a poster sized print of a Velvia slide at f/32 that turned out really good, printed from a high resolution scan, in the other room.
https://www.fredmiranda.com/forum/topic/1517588/
So no, I'm not interested in hearing about how i'm not supposed to shoot past f/5.6-8, because of the pseudo science of diffraction as practiced on photo forums. Just because your lens got less sharp after its best aperture doesn't mean there's a law of science applying to every lens saying you...Show more →
Sorry, they look pretty bad to me even here at the tiny web resolution. Again, if YOU are happy with that look, then so be it. But I can see the loss even in the small samples you posted...
Jan 12, 2026 at 12:36 PM
p.5 #16Focus Beyond Infinity
mdude85 wrote:
As I'm sure you know, Ansel Adam's prints...
Tell me that you missed the point I was making without saying that you missed the point that I was making... ;-)
As I'm sure you know, Ansel Adam's prints...
Tell me that you missed the point I was making without saying that you missed the point that I was making... ;-)
Jan 12, 2026 at 01:40 PM
p.5 #17Focus Beyond Infinity
gdanmitchell wrote:
Tell me that you missed the point I was making without saying that you missed the point that I was making... ;-)
I didn't miss your point at all -- I'm simply responding to the statements that you wrote in your comments.
mdude85 wrote
As I'm sure you know, Ansel Adam's prints...I didn't miss your point at all -- I'm simply responding to the statements that you wrote in your comments.
Jan 12, 2026 at 02:23 PM
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p.5 #18Focus Beyond Infinity
Jack Flesher wrote:
AmbientMike wrote
Here's one I shot at f/32 on m4/3, using a lens thats more ok to good than great at that aperture. Also I have a poster sized print of a Velvia slide at f/32 that turned out really good, printed from a high resolution scan, in the other room.https://www.fredmiranda.com/forum/topic/1517588/
So no, I'm not interested in hearing about how i'm not supposed to shoot past f/5.6-8, because of the pseudo science of diffraction as practiced on photo forums. Just because your lens got less sharp after its best aperture doesn't mean there's a law of science applying to every lens saying you must use wider apertures. I have a pretty good idea what lenses might, or might not, work at f/16+
800 pixels is required for the assignments.
But if you think theres a law of nature because your lens got less sharp after 5.6 its not surprising you didn't know that. You just don't have a clue
Jan 12, 2026 at 04:30 PM
p.5 #19Focus Beyond Infinity
Here is my gratuitous contribution about diffraction - yes it is real and applies to all light traveling past a physical edge that blocks light, aperture blades of lenses included. It is not something that can be avoided with better lens design, within a given format. However, larger formats will suffer from less diffraction at any given aperture, but they will also have less depth of field.
At the same time it is wrong to have a blanket rule that says one should not shoot past the diffraction limit. As G Dan has pointed out, sometimes one will want to trade the extra depth of field for a slight softening of the image. A good example is macro work where before focus stacking was available a lot of subjects were shot on FF at f16-f22 or even f32.
To put this softening into perspective, if you look at a website like Optical Limits which tests for lens sharpness at different apertures, you will notice most Fuji APSC lenses tend to show softening beyond f8, ie f11 tends to show less resolution than f8. However, even at f11 many lenses show better performance than they do wide open, and most lenses these days show quite useable performance wide open. F16 might show further softening but again this might still be comparable to a wide-open shot in terms of sharpness.
When I shoot on Fuji, most of the time I don't go past f8 because I mostly don't need it, but on the occasions where I might have accidently dialed in f11 to f16 I haven't noticed diffraction badly softening the image.
There are also a lot of other things that affect perceived sharpness. Sharpening in post-processing, and adding contrast/clarity add sharpness, while adding saturation can reduce it. If shooting film, the choice of film stock makes huge difference.
At the same time it is wrong to have a blanket rule that says one should not shoot past the diffraction limit. As G Dan has pointed out, sometimes one will want to trade the extra depth of field for a slight softening of the image. A good example is macro work where before focus stacking was available a lot of subjects were shot on FF at f16-f22 or even f32.
To put this softening into perspective, if you look at a website like Optical Limits which tests for lens sharpness at different apertures, you will notice most Fuji APSC lenses tend to show softening beyond f8, ie f11 tends to show less resolution than f8. However, even at f11 many lenses show better performance than they do wide open, and most lenses these days show quite useable performance wide open. F16 might show further softening but again this might still be comparable to a wide-open shot in terms of sharpness.
When I shoot on Fuji, most of the time I don't go past f8 because I mostly don't need it, but on the occasions where I might have accidently dialed in f11 to f16 I haven't noticed diffraction badly softening the image.
There are also a lot of other things that affect perceived sharpness. Sharpening in post-processing, and adding contrast/clarity add sharpness, while adding saturation can reduce it. If shooting film, the choice of film stock makes huge difference.
Jan 12, 2026 at 05:18 PM
p.5 #20Focus Beyond Infinity
Geoff D F wrote:
Here is my gratuitous contribution about diffraction - yes it is real and applies to all light traveling past a physical edge that blocks light, aperture blades of lenses included. It is not something that can be avoided with better lens design, within a given format. However, larger formats will suffer from less diffraction at any given aperture, but they will also have less depth of field.
At the same time it is wrong to have a blanket rule that says one should not shoot past the diffraction limit. As G Dan has pointed out, sometimes one will want...Show more →
Thanks, Geoff. That’s very much in line with my earlier points. :-)
Here is my gratuitous contribution about diffraction - yes it is real and applies to all light traveling past a physical edge that blocks light, aperture blades of lenses included. It is not something that can be avoided with better lens design, within a given format. However, larger formats will suffer from less diffraction at any given aperture, but they will also have less depth of field.
At the same time it is wrong to have a blanket rule that says one should not shoot past the diffraction limit. As G Dan has pointed out, sometimes one will want...Show more →
Thanks, Geoff. That’s very much in line with my earlier points. :-)
Jan 12, 2026 at 10:20 PM