p.16 #1 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
AcuteShadows wrote:
DSLR now has faster AF than mirrorless. I assume this primarily due to the fact that a mirrorless camera must limit the area dedicated to AF on the sensor in order not to degrade image quality. If you have AF away from the image sensor, you can use the entire area for AF. Or, alternatively, you can use some of the area for image analysis, and the remaining part for phase AF. As you don't need perfect image quality for image analysis, the area dedicated to AF can be larger in this case.
"DSLR now has faster AF than mirrorless." That statement in itself is very misleading and too general to be valid. AFC, AFS? Initial AF acquisition? Tracking? Wide open or stopped down? Good light or bad light?
My experience is in many cases and situation the opposite of what you claim. I used high end DSLRs too, for quite some time in parallel professionally, so know the differences quite well. In addition, the fastest AF is not helpful if AF accuracy is lacking.
p.16 #2 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
Holger wrote:
"DSLR now has faster AF than mirrorless." That statement in itself is very misleading and too general to be valid. AFC, AFS? Initial AF acquisition? Tracking? Wide open or stopped down? Good light or bad light?
My experience is in many cases and situation the opposite of what you claim. I used high end DSLRs too, for quite some time in parallel professionally, so know the differences quite well. In addition, the fastest AF is not helpful if AF accuracy is lacking.
So I'd state it this way: DSLR can work with a dedicated phase-detect sensor, potentially allowing it to have faster AF than cameras without a dedicated PDAF sensor. We know about the pitfalls with fine tuning phase-detection on a separate sensor, with fine tuning adjustments dependent on temperatur, light spectrum etc. My experience (D750 vs Z6) is that
(a) D750 is faster, and I can fine tune AF quite accurately on primes (for zooms, it depends a lot on the lens copy),
(b) with moving subject, contrast-detect AF sometimes gets confused and starts to wobble in order to adjust (or maybe just confirm) focus, thus resulting in effictive down-time of the camera during this activity,
(c) I was able to realize better accuracy of the Z6 contrast AF only with perfectly still subjects, and the difference is not noticeable in most cases (I have no zoom for the Z6 right now, it may be more helpful with zooms due to fine tune problems with DSLR zooms.)
I would limit my observations to AF-S and AF-C without camera movement, i.e. tracking. The above observations apply to wide open shots in good to moderate light.
May 05, 2019 at 06:07 AM
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p.16 #3 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
AcuteShadows wrote:
So I'd state it this way: DSLR can work with a dedicated phase-detect sensor, potentially allowing it to have faster AF than cameras without a dedicated PDAF sensor. We know about the pitfalls with fine tuning phase-detection on a separate sensor, with fine tuning adjustments dependent on temperatur, light spectrum etc. My experience (D750 vs Z6) is that
(a) D750 is faster, and I can fine tune AF quite accurately on primes (for zooms, it depends a lot on the lens copy),
(b) with moving subject, contrast-detect AF sometimes gets confused and starts to wobble in order to adjust (or maybe just confirm) focus, thus resulting in effictive down-time of the camera during this activity,
(c) I was able to realize better accuracy of the Z6 contrast AF only with perfectly still subjects, and the difference is not noticeable in most cases (I have no zoom for the Z6 right now, it may be more helpful with zooms due to fine tune problems with DSLR zooms.)
I would limit my observations to AF-S and AF-C without camera movement, i.e. tracking. The above observations apply to wide open shots in good to moderate light. ...Show more →
Well, I would say if you are basing your statements on the two cameras you have used then I don't think those statements will apply to DSLRs and mirrorless cameras in general. The Z6 in particular is a brand new mirrorless and it hasn't even had its first firmware upgrade. It is not a good indicator of focus speed of a mirrorless camera. The Sony A9 is now state of the art with focus speed of a mirrorless camera and it is way faster than any other mirrorless and most report a bit faster than any current DSLR. DSLR's dedicated AF sensors as we have discussed previously in this thread have pluses and minuses. Because they are dedicated to just AF they can be designed specifically for that task that is a big plus, but because they only get a fraction of the light entering the camera and only the central portion of the light (big minuses) they have to compensate. This means to get good low light AF, they have to use bigger sensor sites to collect more light and for tracking they have less space to work with (only that central portion of light, so they have less data with which to work. Both the smaller area covered by AF and the bigger sensor means they have less data. That can be good for speed, but if you can process the data less data is a distinct disadvantage. The A9 is showing us just what can be done with all that data if you have enough processing power. As processing power increases the district advantage of using the whole sensor for AF will become more apparent.
p.16 #4 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
Steve Spencer wrote:
Well, I would say if you are basing your statements on the two cameras you have used then I don't think those statements will apply to DSLRs and mirrorless cameras in general. The Z6 in particular is a brand new mirrorless and it hasn't even had its first firmware upgrade. It is not a good indicator of focus speed of a mirrorless camera. The Sony A9 is now state of the art with focus speed of a mirrorless camera and it is way faster than any other mirrorless and most report a bit faster than any current DSLR. DSLR's dedicated AF sensors as we have discussed previously in this thread have pluses and minuses. Because they are dedicated to just AF they can be designed specifically for that task that is a big plus, but because they only get a fraction of the light entering the camera and only the central portion of the light (big minuses) they have to compensate. This means to get good low light AF, they have to use bigger sensor sites to collect more light and for tracking they have less space to work with (only that central portion of light, so they have less data with which to work. Both the smaller area covered by AF and the bigger sensor means they have less data. That can be good for speed, but if you can process the data less data is a distinct disadvantage. The A9 is showing us just what can be done with all that data if you have enough processing power. As processing power increases the district advantage of using the whole sensor for AF will become more apparent....Show more →
Sony AF is indeed said to be superior to Nikon Z. Yet it might be even better if it were able to use more of the sensor area for AF purposes. So my alternative suggestion is to use the second sensor, and dedicate 25% of its area to image analysis. (I would think that eye recoginition and deep learning does not need every pixel and can work almost as well with 25% instead of 100% or 90% of the image area.) That would leave 75% for AF purposes, and if Sony uses this better than Nikon, then we have an even better camera. (I have bought the Z6 due to legacy glass, using Leica M and Voigtländer glass and for video and low-light capability. If I would actually need AF on the mirrorless, I may well have chosen the Sony.)
May 05, 2019 at 07:54 AM
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p.16 #5 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
AcuteShadows wrote:
Sony AF is indeed said to be superior to Nikon Z. Yet it might be even better if it were able to use more of the sensor area for AF purposes. So my alternative suggestion is to use the second sensor, and dedicate 25% of its area to image analysis. (I would think that eye recoginition and deep learning does not need every pixel and can work almost as well with 25% instead of 100% or 90% of the image area.) That would leave 75% for AF purposes, and if Sony uses this better than Nikon, then we have an even better camera. (I have bought the Z6 due to legacy glass, using Leica M and Voigtländer glass and for video and low-light capability. If I would actually need AF on the mirrorless, I may well have chosen the Sony.) ...Show more →
The huge problem with your suggestion is that if you put deep learning into a DSLR AF sensor you are starting with a system that is hugely handicapped. It has less light than a mirrorless. It covers a much smaller part of the image and now you are going to restrict that to just a quarter of that already much smaller part of the image. To me that is just a fools errand and will never be able to compete with the deep learning with better light, less restrictions of the sensor, and a lot more data in a mirrorless. It would seem it you are going down that road you are doomed to have your DSLR AF system trounced by mirrorless systems for all the deep learning stuff. For that more data is clearly better and of course more light is always better and you are going to try to build a system that you know ahead of time has less light and less data.
p.16 #6 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
AcuteShadows wrote:
So I'd state it this way: DSLR can work with a dedicated phase-detect sensor, potentially allowing it to have faster AF than cameras without a dedicated PDAF sensor. We know about the pitfalls with fine tuning phase-detection on a separate sensor, with fine tuning adjustments dependent on temperatur, light spectrum etc. My experience (D750 vs Z6) is that
(a) D750 is faster, and I can fine tune AF quite accurately on primes (for zooms, it depends a lot on the lens copy),
(b) with moving subject, contrast-detect AF sometimes gets confused and starts to wobble in order to adjust (or maybe just confirm) focus, thus resulting in effictive down-time of the camera during this activity,
(c) I was able to realize better accuracy of the Z6 contrast AF only with perfectly still subjects, and the difference is not noticeable in most cases (I have no zoom for the Z6 right now, it may be more helpful with zooms due to fine tune problems with DSLR zooms.)
I would limit my observations to AF-S and AF-C without camera movement, i.e. tracking. The above observations apply to wide open shots in good to moderate light. ...Show more →
That's what I thought. I used the D750 professionally and the A9 smokes it. The A73 is at least as fast, I find it faster than the D750, too. With both I never use CDAF, but PDAF, as with dslrs. Much quicker in my experience. With moving targets I don't see any reason to use CDAF at all. OSPDAF on the Sony is so accurate, that I don't need the extra CDAF step.
My keeper rate with the Sonys is much higher than that with the D750, even in controlled situations, as the side AF points in the D750 cause front/backfocus with fast lenses (f1.4) most of the time.
You cannot fine tune a prime to all situations (close up to far away targets, center and all border AF points, artificial vs. natural light etc.).
Using those cameras side by side at weddings I quickly realised that I don't want to use dslrs anymore. Others differ in their assessment, but thats my experience.
The z6/z7 is Nikon's first attempt. AF performance in my experience isn't up to the Sonys, clearly. That will improve with further generations, I am sure.
p.16 #7 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
Steve Spencer wrote:
The huge problem with your suggestion is that if you put deep learning into a DSLR AF sensor you are starting with a system that is hugely handicapped. It has less light than a mirrorless. It covers a much smaller part of the image and now you are going to restrict that to just a quarter of that already much smaller part of the image. To me that is just a fools errand and will never be able to compete with the deep learning with better light, less restrictions of the sensor, and a lot more data in a mirrorless. It would seem it you are going down that road you are doomed to have your DSLR AF system trounced by mirrorless systems for all the deep learning stuff. For that more data is clearly better and of course more light is always better and you are going to try to build a system that you know ahead of time has less light and less data. ...Show more →
Yes, somewhat my suggestion is predicated on the assumption that deep learning or other instant analysis doesn't need 100% information, i.e. that it works almost as well at ISO 3200 as at ISO 100. I do not do image analysis, so I actually do not know if that is true. As for the image are that is covered by the AF sensor: that is a function of the sensor size and the flange distance. Of course, you would want to keep the flange distance as low as possible. But you can, in principle, use a medium format flange distance and increase the mirrors accordingly, thus resulting in a much larger AF area on a full frame sensor. So I tend to think this would be feasible in theory, and actually result in better image quality, it is also doubtful whether many people would want to carry around a medium format size camera to shoot full frame.
p.16 #8 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
D850, D5 and D500 have cross type points at the edges of the AF sensor array and these work far better than the 2007 Multi-CAM 3500 or its derivatives.
It is interesting how people compare the latest 4000€ 2017 mirrorless with older 2014 DSLR of less than half price and think the comparison is fair. Compare the D750 with A7 III or II.
p.16 #9 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
Holger wrote:
That's what I thought. I used the D750 professionally and the A9 smokes it. The A73 is at least as fast, I find it faster than the D750, too. With both I never use CDAF, but PDAF, as with dslrs. Much quicker in my experience. With moving targets I don't see any reason to use CDAF at all. OSPDAF on the Sony is so accurate, that I don't need the extra CDAF step.
My keeper rate with the Sonys is much higher than that with the D750, even in controlled situations, as the side AF points in the D750 cause front/backfocus with fast lenses (f1.4) most of the time.
You cannot fine tune a prime to all situations (close up to far away targets, center and all border AF points, artificial vs. natural light etc.).
Using those cameras side by side at weddings I quickly realised that I don't want to use dslrs anymore. Others differ in their assessment, but thats my experience.
The z6/z7 is Nikon's first attempt. AF performance in my experience isn't up to the Sonys, clearly. That will improve with further generations, I am sure....Show more →
I concur that while fine tuning zooms is much less effective than fine tuning zooms, there are remaining issues with primes, as you do mention. I have not noticed the issues with side AF points on the D750 that you are reporting, but I have not tested it specifically for it. I think that for wedding (generally non-erratic and slower movements) a mirrorless is just fine. My last test subject for AF was bird that strayed into my house yesterday, was somewhat confused and acted accordingly. The Z6 was just too slow, and with the D750, half of the misses were due to me not getting the focus point quickly enough on the birds head, and the other half were due to insufficient AF capability of the D750. With a D5, I would probably be solely responsible for the vast majority of misses.
May 05, 2019 at 09:04 AM
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p.16 #10 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
AcuteShadows wrote:
Yes, somewhat my suggestion is predicated on the assumption that deep learning or other instant analysis doesn't need 100% information, i.e. that it works almost as well at ISO 3200 as at ISO 100. I do not do image analysis, so I actually do not know if that is true. As for the image are that is covered by the AF sensor: that is a function of the sensor size and the flange distance. Of course, you would want to keep the flange distance as low as possible. But you can, in principle, use a medium format flange distance and increase the mirrors accordingly, thus resulting in a much larger AF area on a full frame sensor. So I tend to think this would be feasible in theory, and actually result in better image quality, it is also doubtful whether many people would want to carry around a medium format size camera to shoot full frame. ...Show more →
I think using a medium format mirror for a DSLR to have this sort of sensor in a DSLR would be a complete non-starter as you would need a whole new mount and a whole new set of lenses and they would be big ass lenses. That makes even less sense to me. Feasible in theory, but completely impractical and what seems to me a pretty obvious way one would not want to go. My point isn't that it is impossible to do with a DSLR, just that it isn't at all practical to do so and anyone to try it I think would be putting themselves at an obvious disadvantage to mirrorless cameras.
p.16 #11 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
Steve Spencer wrote:
I think using a medium format mirror for a DSLR to have this sort of sensor in a DSLR would be a complete non-starter as you would need a whole new mount and a whole new set of lenses and they would be big ass lenses. That makes even less sense to me. Feasible in theory, but completely impractical and what seems to me a pretty obvious way one would not want to go. My point isn't that it is impossible to do with a DSLR, just that it isn't at all practical to do so and anyone to try it I think would be putting themselves at an obvious disadvantage to mirrorless cameras. ...Show more →
A longer flange distance does not necessarily mean bigger lenses. For example, Nikon MF glass is not larger than Zeiss MF glass for M mount. For maximum image quality, you would need big lenses anyway (Leica lenses, despite being top image quality, show a lot of vignetting due to their size, and that means you are shooting at ISO 800 effectively, in the corners), and image quality is the main - if not the only - reason for such a type of camera. Lenses such as the Sigma Art 1.4/40 or the Zeiss Milvus 1.4/35 do indeed find customers, so 15mm of additional flange distance would not be that much of a deal for some. But it would probably be a niche product.
p.16 #13 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
ilkka_nissila wrote:
D850, D5 and D500 have cross type points at the edges of the AF sensor array and these work far better than the 2007 Multi-CAM 3500 or its derivatives.
It is interesting how people compare the latest 4000€ 2017 mirrorless with older 2014 DSLR of less than half price and think the comparison is fair. Compare the D750 with A7 III or II.
Nikon owners probably shouldn't compare the D750 with an A7 III... or any other modern camera.
May 05, 2019 at 12:14 PM
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p.16 #14 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
AcuteShadows wrote:
A longer flange distance does not necessarily mean bigger lenses. For example, Nikon MF glass is not larger than Zeiss MF glass for M mount. For maximum image quality, you would need big lenses anyway (Leica lenses, despite being top image quality, show a lot of vignetting due to their size, and that means you are shooting at ISO 800 effectively, in the corners), and image quality is the main - if not the only - reason for such a type of camera. Lenses such as the Sigma Art 1.4/40 or the Zeiss Milvus 1.4/35 do indeed find customers, so 15mm of additional flange distance would not be that much of a deal for some. But it would probably be a niche product. ...Show more →
This is wrong on a number of fronts. A longer registration distance means more lenses will have to be built as retro focal. Have you ever looked at 50mm lenses on MF, even f/3.5 lenses are huge. Your proposition also isn't just making the registration distance longer--to get the gains you want you would also have to make the flange bigger. All of this means bigger lenses and you are just wrong about Nikon manual focus glass not being bigger for DSLR than rangefinders. The proper comparison there is not Nikon to Zeiss (which often builds bigger lenses) but rather Nikon to Nikon. In the same era Nikon manual focus DSLR lenses are much bigger than their rangefinder lenses and that is true for every other manufacturer as well. If you put a medium format mirror in a FF 35mm DSLR there is no question the lenses will necessarily be a lot bigger. Not the longest lenses, but everything else.
p.16 #15 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
ilkka_nissila wrote:
D850, D5 and D500 have cross type points at the edges of the AF sensor array and these work far better than the 2007 Multi-CAM 3500 or its derivatives.
It is interesting how people compare the latest 4000€ 2017 mirrorless with older 2014 DSLR of less than half price and think the comparison is fair. Compare the D750 with A7 III or II.
He brought up the D750 for comparison, that's why.
The latest DSLRs are of course better, but that still doesn't help wrt focus accuracy for example, as J. Kasson has demonstrated.
I used the D5, too, before deciding for the A9. Of course it does better than a D750 but I still observed front-/backfocus esp. with outer AF points wide open.
I didn't want to lug it around for 12h continuously at weddings, too. To each his own.
May 05, 2019 at 12:33 PM
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p.16 #16 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
ilkka_nissila wrote:
D850, D5 and D500 have cross type points at the edges of the AF sensor array and these work far better than the 2007 Multi-CAM 3500 or its derivatives.
It is interesting how people compare the latest 4000€ 2017 mirrorless with older 2014 DSLR of less than half price and think the comparison is fair. Compare the D750 with A7 III or II.
Interesting choice of language. At the edge of the AF array is nowhere near at the edge of the image. The AF points are still seriously clustered in the center of the frame. That is a physical limitation that you cannot solve with a DSLR unless you want to make a crazy new mount in which you put a huge mirror (medium format size at least) and all the problems that will cause just so you can AF to the edges of the FF 35mm sensor.
p.16 #18 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
henry albert wrote:
And that, ladies and germs, is why cross posting to the Sony Fanboy Infestation, uh, Forum, is guaranteed to embarrass the photographic community.
I posted that as a former Nikon "fanboy"... who was gullible enough to buy a D750 that was already obsolete when it was introduced in 2014. Realizing my mistake and abandoning that sinking ship doesn't make me a fanboy of any other brand... but I guess that's how the really zealous Nikon fanboii see the world.
p.16 #20 · FF Mirrorless, what's it going to take Sony, Canon, Nikon
I have included my cross post comments and that threads should be appropriately placed in threads where people can contribute rather than being inundated.
The point of this article is that photographers are and still continuing to use DSLR's along with their lenses. Sure many will also have MILC's too. We have Nikon/Canon threads where many of us still love using our DSLR's with/without MILC's alongside. The discussions get off track as many cannot accept that there are many photographers that still love to use DSLR's alongside MILC's. Sure the future is MILC's but DSLR's will be around for quite some time.
The issue is more of acceptance of both DSLR and MILC technology and we as photographers choose what suits rather than brand trench warfare
As many know me, I was there when Leica first introduced in 2010 with the M9, the first small/light FF body with superb lenses. Amazing system and still is. I was also there with Sony introduced the A7r in 2013, and then continued with the A7s, A7II, RX1, RXr and several A7rII's. I now have the D850/D750 which is very counter intuitive for many people but I love the system for now. With FF photography and fast lenses there are diminishing returns in size/weight but more important the large cost in changing systems.
There should be more photography and less brand tribalism
