P4P f-stop sweet spot?

[Raptorman0909]

There is NO ideal apterure for a DSLR that translates to all lenses. Your previous post made it sound as if there WAS such an f/stop. I have been a professional architectural photographer for 35 years. Each lens needs to be tested. Most WILL end up with the greatest detail being just under where diffraction starts to appear, but not all.

Rather than encouraging someone to just use f/7.1 as their go-to best aperture on a DSLR, why not encourage them to explore their own gear with a series of simple tests that will be tailored exactly to their lenses?

I will say this one more time - I have a lens for a full frame DSLR (Canon 5Ds is what I use it on) and it is far superior at f/11 than it is at f/8 and f/16. I have owned 4 of these lenses in fact. They have ALL found their best performance at f/11. I know someone who is perhaps one of the best architectural shooters in the world who I told about this lens. He bought one, tested it and... surprise surprise, he reports the sweet spot at a very obvious f/11 too.

Test your gear people. It is not as simple as you think it is. But it's not hard to find out the truth with just a few minutes of your time.

Yes, there is variations in lenses and that can skew the preferred setting up or down a bit, but diffraction limiting is NOT a function of the lens and is entirely down to Physics and no matter how brilliant the lens maker is and how beautifully the lens is made the diffraction issue is always there. For landscape and other non-drone photography you sometimes want to limit the DOF so it's advised to use a lower f/# and at other times you can't help but include nearby and distant features that you want decently sharp so for that situation you can easily go well above f/16. You will lose some sharpness when stopped down like that, but as others have said you do not always want the image to be super sharp.

But, drones change the picture in a couple ways: first, the sensors are smaller so the f/# you need to use to get comparable sharpness tends to be lower and as I mentioned with the GoPro type cameras with fixed aperture at about f/2.8 they still get decently sharp images and DOF owing to the small sensor size. Additionally, we tend to have less near-ground objects as we tend to fly a 100 or so feet above the ground thereby limiting the presence of close objects and we can therefore run with a lower f/# and still have things sharp.

I have not demanded everyone follow my guidelines as my posts were just that -- guidelines, a place to start. With smaller sensors it's not so easy to get background blurring due to the two facts of being, generally, further away from the close objects; and secondly, the sensors being smaller tend to produce a greater DOF at the same f/#.

Lastly, if you have a full frame DSLR lens that is sharper at f/11 than f/8 then I can say with absolute certainty that you are either mistaken or the lens isn't all that great! Most lenses are sharpest a stop or two down from wide open so an f/1.4 lens would typically be sharpest around f/4ish. Of course, that's before you take into account the diffraction issue which is not related to lens quality or construction. My best lens for sharpness, the Zeiss Distagon 21mm that I use on my Nikon D800E's, is sharp center to edge and I get the greatest detail right at f/7.1. The lens is sharpest around f/5 but stopping down a bit increases DOF. Beyond f/7.1 the efffects of diffraction, which are present even at f/4, begins to overwhelm the DOF improvements with smaller aperture so the detail tens to diminish.

For the P4P with the much smaller sensor than my D800E's the aperture where max image detail occurs tends to be more like f/5 or f/5.6 but can be as low as f/4. For my D800E's I get max detail around f/5.6 to f/8 with some small variation in lenses but more as a result of different scenes.


Brian

 

[Jim Roof]

Yes, there is variations in lenses and that can skew the preferred setting up or down a bit, but diffraction limiting is NOT a function of the lens and is entirely down to Physics and no matter how brilliant the lens maker is and how beautifully the lens is made the diffraction issue is always there. For landscape and other non-drone photography you sometimes want to limit the DOF so it's advised to use a lower f/# and at other times you can't help but include nearby and distant features that you want decently sharp so for that situation you can easily go well above f/16. You will lose some sharpness when stopped down like that, but as others have said you do not always want the image to be super sharp.

But, drones change the picture in a couple ways: first, the sensors are smaller so the f/# you need to use to get comparable sharpness tends to be lower and as I mentioned with the GoPro type cameras with fixed aperture at about f/2.8 they still get decently sharp images and DOF owing to the small sensor size. Additionally, we tend to have less near-ground objects as we tend to fly a 100 or so feet above the ground thereby limiting the presence of close objects and we can therefore run with a lower f/# and still have things sharp.

I have not demanded everyone follow my guidelines as my posts were just that -- guidelines, a place to start. With smaller sensors it's not so easy to get background blurring due to the two facts of being, generally, further away from the close objects; and secondly, the sensors being smaller tend to produce a greater DOF at the same f/#.

Lastly, if you have a full frame DSLR lens that is sharper at f/11 than f/8 then I can say with absolute certainty that you are either mistaken or the lens isn't all that great! Most lenses are sharpest a stop or two down from wide open so an f/1.4 lens would typically be sharpest around f/4ish. Of course, that's before you take into account the diffraction issue which is not related to lens quality or construction. My best lens for sharpness, the Zeiss Distagon 21mm that I use on my Nikon D800E's, is sharp center to edge and I get the greatest detail right at f/7.1. The lens is sharpest around f/5 but stopping down a bit increases DOF. Beyond f/7.1 the efffects of diffraction, which are present even at f/4, begins to overwhelm the DOF improvements with smaller aperture so the detail tens to diminish.

For the P4P with the much smaller sensor than my D800E's the aperture where max image detail occurs tends to be more like f/5 or f/5.6 but can be as low as f/4. For my D800E's I get max detail around f/5.6 to f/8 with some small variation in lenses but more as a result of different scenes.


Brian

'Lastly, if you have a full frame DSLR lens that is sharper at f/11 than f/8 then I can say with absolute certainty that you are either mistaken or the lens isn't all that great!'

Brian,

I am not mistaken and the Olympus Zuiko 35mm f/2.8 PC lens is a freaking dream. I have owned FOUR of them. Why? Because so FEW people know about this lens and how well it performs on even a 50 megapixel full frame DSLR - you can pick one up on eBay for around 350.00. The reason I went through FOUR of these is due to the mechanics of how the lens shifts. I also bought two of them for under 300.00 that I turned for a quick profit after picking the one that was the best of the lot and keeping it.

At f/11, this lens is every bit as sharp as both my Canon 17mm TS/E (this is the sharpest ultra wide prime Canon has ever made - a beast of a lens) and the Canon 24mm TS/E Mark II, also a monster of a performer.

I do not appreciate your insinuation that I am wrong about what I am talking about when I have, in fact, tested this particular lens extensively.

You, on the other hand, have likely never even laid EYES on this particular lens.

 

[Raptorman0909]

'Lastly, if you have a full frame DSLR lens that is sharper at f/11 than f/8 then I can say with absolute certainty that you are either mistaken or the lens isn't all that great!'

Brian,

I am not mistaken and the Olympus Zuiko 35mm f/2.8 PC lens is a freaking dream. I have owned FOUR of them. Why? Because so FEW people know about this lens and how well it performs on even a 50 megapixel full frame DSLR - you can pick one up on eBay for around 350.00. The reason I went through FOUR of these is due to the mechanics of how the lens shifts. I also bought two of them for under 300.00 that I turned for a quick profit after picking the one that was the best of the lot and keeping it.

At f/11, this lens is every bit as sharp as both my Canon 17mm TS/E (this is the sharpest ultra wide prime Canon has ever made - a beast of a lens) and the Canon 24mm TS/E Mark II, also a monster of a performer.

I do not appreciate your insinuation that I am wrong about what I am talking about when I have, in fact, tested this particular lens extensively.

You, on the other hand, have likely never even laid EYES on this particular lens.

Jim, I wish no insult, but Physics doesn't agree with your argument that f/11 is sharpest. I think what you maybe confusing is sharpness and detail. For architectural photography I'd guess you have objects of interest that are very close as well as objects that are farther away and in that condition a smaller aperture, say f/11, would give more DETAIL than at f/8 owing to the greater DOF. DOF and detail are not the same thing as sharpness and there's no way that lens or any such DSLR lens is sharpest at f/11. As I said, the only logical thing is that the lens is best at there but only because it's not so good elsewhere. Again, your particular use case may well demand the use of a smaller aperture because DOF rules but f/11 will never in a million years be optimum for sharpness due to diffraction -- you do not get a vote on this -- it's Physics pure and simple!

But, getting back to the OP topic (P4P f-stop sweet-spot) ... for most drone shooters there will not generally be much detail that's real close to the camera and the ratio of near to far is far smaller than when shooting from the ground so one does not need the same DOF settings with the aperture. You can comfortably shoot in the f/4-f/5.6 range and get great detail and stopping down to smaller than f/5.6 will only tend to reduce detail given the fact that an increase in DOF will be pretty small whereas the decrease in sharpness due to diffraction will become more significant.

Of course there can be situations where a drone pilot may be real close to object they wish to be in decent focus while keeping the rest of the FOV in decent focus so for that situation you may trade a bit of sharpness for greater detail by stopping down a bit more than f/5.6. Similarly, if you really want to blur the background then getting real close and using a wide open aperture would do the trick though that tends to worsen the chromatic aberrations and vignetting.

Again, I do not wish to insult you or anyone else, trolling aint my bag, but for a small sensor camera such as the P4P going to f/11 would have a negligible increase in DOF but the decrease in sharpness due to diffraction is a killer. For a drone camera a hundred feet away from the closest object the need to stop down to achieve DOF just doesn't exist and using a larger aperture keeps you at the sharper end and away from diffraction limiting.

Brian

 

[Jim Roof]

Jim, I wish no insult, but Physics doesn't agree with your argument that f/11 is sharpest. I think what you maybe confusing is sharpness and detail. For architectural photography I'd guess you have objects of interest that are very close as well as objects that are farther away and in that condition a smaller aperture, say f/11, would give more DETAIL than at f/8 owing to the greater DOF. DOF and detail are not the same thing as sharpness and there's no way that lens or any such DSLR lens is sharpest at f/11. As I said, the only logical thing is that the lens is best at there but only because it's not so good elsewhere. Again, your particular use case may well demand the use of a smaller aperture because DOF rules but f/11 will never in a million years be optimum for sharpness due to diffraction -- you do not get a vote on this -- it's Physics pure and simple!

But, getting back to the OP topic (P4P f-stop sweet-spot) ... for most drone shooters there will not generally be much detail that's real close to the camera and the ratio of near to far is far smaller than when shooting from the ground so one does not need the same DOF settings with the aperture. You can comfortably shoot in the f/4-f/5.6 range and get great detail and stopping down to smaller than f/5.6 will only tend to reduce detail given the fact that an increase in DOF will be pretty small whereas the decrease in sharpness due to diffraction will become more significant.

Of course there can be situations where a drone pilot may be real close to object they wish to be in decent focus while keeping the rest of the FOV in decent focus so for that situation you may trade a bit of sharpness for greater detail by stopping down a bit more than f/5.6. Similarly, if you really want to blur the background then getting real close and using a wide open aperture would do the trick though that tends to worsen the chromatic aberrations and vignetting.

Again, I do not wish to insult you or anyone else, trolling aint my bag, but for a small sensor camera such as the P4P going to f/11 would have a negligible increase in DOF but the decrease in sharpness due to diffraction is a killer. For a drone camera a hundred feet away from the closest object the need to stop down to achieve DOF just doesn't exist and using a larger aperture keeps you at the sharper end and away from diffraction limiting.

Brian

I am not even talking about the lens on the P4P. I was talking about a lens for a full frame DSLR. And I am talking about SHARPNESS.

Maybe you thought I was somehow claiming that f/11 was the sweet spot for a P4P. I think it is more like f/4. The f/11 was for the Olympus Zuiko f/2.8 35mm PC lens, multicoated version on a 5Ds. I have independent corroboration on this from someone who was doing their own tests.

 

[With The Birds]

Jim, I wish no insult, but Physics doesn't agree with your argument that f/11 is sharpest. I think what you maybe confusing is sharpness and detail. For architectural photography I'd guess you have objects of interest that are very close as well as objects that are farther away and in that condition a smaller aperture, say f/11, would give more DETAIL than at f/8 owing to the greater DOF. DOF and detail are not the same thing as sharpness and there's no way that lens or any such DSLR lens is sharpest at f/11. As I said, the only logical thing is that the lens is best at there but only because it's not so good elsewhere. Again, your particular use case may well demand the use of a smaller aperture because DOF rules but f/11 will never in a million years be optimum for sharpness due to diffraction -- you do not get a vote on this -- it's Physics pure and simple!

But, getting back to the OP topic (P4P f-stop sweet-spot) ... for most drone shooters there will not generally be much detail that's real close to the camera and the ratio of near to far is far smaller than when shooting from the ground so one does not need the same DOF settings with the aperture. You can comfortably shoot in the f/4-f/5.6 range and get great detail and stopping down to smaller than f/5.6 will only tend to reduce detail given the fact that an increase in DOF will be pretty small whereas the decrease in sharpness due to diffraction will become more significant.

Of course there can be situations where a drone pilot may be real close to object they wish to be in decent focus while keeping the rest of the FOV in decent focus so for that situation you may trade a bit of sharpness for greater detail by stopping down a bit more than f/5.6. Similarly, if you really want to blur the background then getting real close and using a wide open aperture would do the trick though that tends to worsen the chromatic aberrations and vignetting.

Again, I do not wish to insult you or anyone else, trolling aint my bag, but for a small sensor camera such as the P4P going to f/11 would have a negligible increase in DOF but the decrease in sharpness due to diffraction is a killer. For a drone camera a hundred feet away from the closest object the need to stop down to achieve DOF just doesn't exist and using a larger aperture keeps you at the sharper end and away from diffraction limiting.

Brian

Let's be clear on the physics before contemplating subjective detail and acceptable sharpness. The P4P pro has a 1" sensor illuminated by an 8.8mm focal length lens (roughly 24mm equiv focal length on a 35mm SLR). The 1" sensor has an effective photosite (often called pixel) size of 6.57um. Any diffraction introduced subjective reduction in image detail should not be apparent below f5.6 (100% crop) and will not be evident to most at apertures of f11 or larger in an 8" by 10" print.

As to DOF (depth of acceptable sharpness either side of the set focus point) it is not smaller sensors that create greater depth of field. DOF is determined by camera to subject distance and magnification. Obviously while the 8.8mm lens on the P4P will provide the same FOV and perspective as a 24mm lens on a full frame camera (for a given subject distance) the full vframe camera requires a longer focal length (higher magnification) lens to achieve the same FOV. It's no different to fitting a longer focal length lens to your SLR where you will see reduced DOF (for a given aperture) as focal length is increased.

 

[With The Birds]

I am not even talking about the lens on the P4P. I was talking about a lens for a full frame DSLR. And I am talking about SHARPNESS.

Maybe you thought I was somehow claiming that f/11 was the sweet spot for a P4P. I think it is more like f/4. The f/11 was for the Olympus Zuiko f/2.8 35mm PC lens, multicoated version on a 5Ds. I have independent corroboration on this from someone who was doing their own tests.

The 16-36 2.8 L is sweetest at f11 on my old 1Ds3 and 1Dx bodies, no question. Interestingly f4 on the P4P is equivalent to f11 on a full frame camera so far as apparent DOF is concerned.

 

[shockwave199]

Just adding what I've seen along the way.

 

[AlanTheBeast]

Just adding what I've seen along the way.

Yep - seen that in the past. Pragmatic. He didn't try f/5.6 which is a bit better than f/4 (P4P) and f/6.3 is acceptable to be sure. Need to also think "video" settings so even with ND 16, you need some stop down in a lot of situations.