Patent: Microadjustment Automated
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Re accuracy of contrast AF detection.
Dual pixel technology is a huge leap forward for this. Live view in the 70D is very fast and the contrast AF spot on. I calibrated my new 70D with both FoCal (very satisfactory) and the sloping ruler method. Live view consistently focussed on the screen with the ruler reading at the correct position. On the other hand, both in Focal and sloping ruler testing, there was the usual spread around the correct focus using phase detect.
Dual pixel technology is much to Canon's credit for both speed and accuracy of contrast detect AF. You would expect from basic statistics that the standard deviation of each reading would improve by the square root of the number of pixels employed in detection.
Dual pixel technology is a huge leap forward for this. Live view in the 70D is very fast and the contrast AF spot on. I calibrated my new 70D with both FoCal (very satisfactory) and the sloping ruler method. Live view consistently focussed on the screen with the ruler reading at the correct position. On the other hand, both in Focal and sloping ruler testing, there was the usual spread around the correct focus using phase detect.
Dual pixel technology is much to Canon's credit for both speed and accuracy of contrast detect AF. You would expect from basic statistics that the standard deviation of each reading would improve by the square root of the number of pixels employed in detection.
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So instead of trying to fix the AF issues, they come up with a ridiculous AFMA solution? At least for me, the AF accuracy and AFMA value depend heavily on the distance to the subject and even the lighting can affect results. Having 1 value for a lens does not fix much. Besides, a slicing golfer can surely aim off fairway at the tee, but that is a lame way to deal with the slice. A better solution is to fix the slice.
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it is the logical fix. I expect that it will only be offered on future new models [presumably all with dual pixel AF sensor] and will not come as a firmware update for any existing cameras (including 1D X and 70D).
To me it sounds like one of the "marketing differentiation features" Canon might use to "justify" a very high 7D II launch price.
Reliability of contrast AF for use in automated AFMA procedure is no issue in my opinion. Not on any current Canon EOS, and even less so in dual-pixel AF systems.
Of course automated in-camera AFMA will not be performed by just pointing the camera at any kind of test scene including white wall/blue sky ... it will be a procedure were owners are given instructions regarding proper "test scene" that has enough contrast/patterns in the right places [= under all AF-fields of the camera's phase AF system]. And procedure will only be initiated and carried out, if test target offers enough contrast and structure/texture to yield proper results.
To me it sounds like one of the "marketing differentiation features" Canon might use to "justify" a very high 7D II launch price.
Reliability of contrast AF for use in automated AFMA procedure is no issue in my opinion. Not on any current Canon EOS, and even less so in dual-pixel AF systems.
Of course automated in-camera AFMA will not be performed by just pointing the camera at any kind of test scene including white wall/blue sky ... it will be a procedure were owners are given instructions regarding proper "test scene" that has enough contrast/patterns in the right places [= under all AF-fields of the camera's phase AF system]. And procedure will only be initiated and carried out, if test target offers enough contrast and structure/texture to yield proper results.
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Dick said:
I didn't read the patent so I don't know for sure but, does it say it only uses one value? Or does it say multiple values are not possible?
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jebrady03 said:
1 value would only be sufficient for "on-the fly/in real time" correction applied to every shot using Phase-AF.
Since this is not feasible [Phase-AF followed by contrast-AF, calculation and application of correction factor for each single shot] there must be a specific "AF-calibration procedure" to be started from the menu or possibly autmatically, every time a lens is mounted on a body that has not been calibrated for that body yet. And similar to current AFMA, there must be a storage matrix for each specific lens, with multiple correction factors for
- a number of different subject distances at
- a number of different f-stop settings in all lenses that are not fully parfocal [= majority of all Canon lenses].
- and in case of a zoom lens, for a number of different focal lengths
If there were a matrix of these correction factors for every single AF-sensor in the camera body, the AFMA-system could even correct for (minor) misalignments of submirror/AF-lens array/AF-sensors. It could have autmatically taken care of the "left-side AF issue" in early Nikon D800 bodies ... to the point that such poblems would not even show up at all. So defintiely a highly desirable feature also from manufacturrers point of view.
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I am excited about this!
While Reikan Focal is a very nice piece software, it is really a pain to do good measurements for the 5D3 / 1DX because you have to change the AFMA values manually. This new functionality could be patched into these firmwares --> huge time saver (although I do not believe that they will provide a new firmware for these cameras)
Even if they implement the new functionality, I still see value in Focal (for example aperture sharpness test)
Sometimes when I calibrate a lens it is fine for let's say a target which is 2 meters away, but it does not really match for a target being 100m away. This method could store many many AFMA values for multiple focus distances on multiple zoom settings.
OK - not a real argument because you could do this manually as well if they implemented it. Would take even more time though. But if this was possible in an automated way I'd love it!
Nobody mentioned it - I'm quite sure they will block 3rd party lenses (eg a lens needs to identify itself correctly).
Even the Sigma USB dock does not really help. I have the 35 Art lens and you can set only 3 focus distances (~0.30 m, ~0.60m, infinity). While the focus is perfect @ f/1.4 for these distances, it is quite off between 0.60m (+14 in the USB Dock tool) and infinity (+3 in the tool). No way to correct that at the moment. Sigma still has issues here.
While Reikan Focal is a very nice piece software, it is really a pain to do good measurements for the 5D3 / 1DX because you have to change the AFMA values manually. This new functionality could be patched into these firmwares --> huge time saver (although I do not believe that they will provide a new firmware for these cameras)
Even if they implement the new functionality, I still see value in Focal (for example aperture sharpness test)
Sometimes when I calibrate a lens it is fine for let's say a target which is 2 meters away, but it does not really match for a target being 100m away. This method could store many many AFMA values for multiple focus distances on multiple zoom settings.
OK - not a real argument because you could do this manually as well if they implemented it. Would take even more time though. But if this was possible in an automated way I'd love it!
Nobody mentioned it - I'm quite sure they will block 3rd party lenses (eg a lens needs to identify itself correctly).
Even the Sigma USB dock does not really help. I have the 35 Art lens and you can set only 3 focus distances (~0.30 m, ~0.60m, infinity). While the focus is perfect @ f/1.4 for these distances, it is quite off between 0.60m (+14 in the USB Dock tool) and infinity (+3 in the tool). No way to correct that at the moment. Sigma still has issues here.
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HEY!
Where is the person who started the thread complaining about Canon's lack of innovation? They should have some interesting insight here
Where is the person who started the thread complaining about Canon's lack of innovation? They should have some interesting insight here
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Don Haines said:HEY!
Where is the person who started the thread complaining about Canon's lack of innovation? They should have some interesting insight here
Is it really innovation or just stealing someone else's idea and be the first to file a patent?
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dilbert said:Don Haines said:HEY!
Where is the person who started the thread complaining about Canon's lack of innovation? They should have some interesting insight here
Something like "I'm not buying another Canon DSLR unless it has this feature!"?
It would certainly be a welcome feature....
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polarhannes said:
+1. I wouldn't be surprised if a change like this would lead to compatibility issues with 3rd party lenses. It would be one thing if 3rd party lenses would function as they had before and the canon lenses gained increased accuracy, etc, but it would be another if the 3rd party lenses are bricked. As much as people complain about Canon bodies not accepting 3rd party batteries after a firmware update, not being able to use 3rd party lenses would be much worse. Not so much an issue for MF lenses only (i.e. Samyang), but it would be a large threat to Sigma/Tamron. Even if Sigma were able to provide updated firmware after a few months, the damage will be done. People may blame Canon for breaking compatibility with 3rd party lenses, but a lot fewer people would be willing to take the risk of buying 3rd party lenses again...
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Albi86 said:
The USB dock is useless. For the 35mm lens you, for example, can only give 1 value for everything that is further than 70 cm away? Correct? At least that is what I was told the other day when I was about to buy a dock. So sensible settings are only available, if you shoot nearby subjects. And for that, I'm fine with my +3. The focus gets messed up when people stand 5 m away from me, whereas for 2 m the +3 still works nicely.
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Loswr
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AlanF said:
My understanding is that DPAF is a phase detect AF system. If the DPAF is used to 'get close' then contrast detect is used for final focus, DPAF is speeding the process up but not making it more accurate. As Mt. Spokane pointed out above, Canon substantially increased the precision of contrast detect AF in recent bodies, and that likely accounts for the increased accuracy of CDAF on the 70D.
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neuroanatomist said:
yes. In the 70D there is a total of 3 AF-systems at work:
A) "regular" DSLR Phase-detect AF [via mirror/submirror/AF-sensor at bottom of mirrorbox)
B) contrast-detect AF - working from sensor feed
C) on-sensor dual-pixel phase-detect AF
combination of B+C = AF-system used in LiveView (and video) only
AFMA correction factors are needed for and work on regular Phase-Detect-AF (A) only.
Automatic calibration of A) could be done using values of B (CD-AF) only or combination of B+C (CD-AF plus on-sensor PD-AF).
The whole AFMA issue will be mute, as soon as all decent cameras will be mirrorless.
MILCs only need one or at most 2 AF-systems ... contrast-detect [speed is solely dependent on porocessing power and algorithms available] and/or on-sensor phase-detect. ;-)
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Dick said:
Yes, correct. Only 1 value for objects being further away than 0.60m (the infinity value).
It focuses perfectly for 0.30m, 0.60m and for infinity (just as configured with the USB dock), but the focus is really off in between of 0.60m and infinity. Don't know what they were thinking when they invented the USB dock, but 0.30m , 0.60m and infinity do not sound like reasonable distances for calibrating a 35mm lens.
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Is this why they crippled Reiken on the 5diii? Canon was not supporting full auto mode last year? If so, could this be available on the 5d3 as a firmware upgrade?
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They brought back support (via the software developer's kit [SDK]) for the 6D (and 70D, I believe), but not the 5DIII and 1DX. No one really seems to know why they have done this, but it seems to be a differentiator between pro/sumer & consumer lines. Perhaps this patent is the reason, because it makes no sense otherwise. The very people who want to do AFMA are most likely 1DX & 5DIII users...K-amps said:
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ashmadux
Art Director, Visual Artist, Freelance Photography
this would be the most greatest thing ever.
Ill do whatever it takes to get the job done, but I truly despise just setting up fOcal- distances of 13 feet away from target, have to purchase long usb cords, need great amounts of light, etc. Its a pain in the ass (sometimes). I went full frame in November, and i have yet to be able to enjoy its benefits because of the ludicrous amount of time and particular setup needed to adjust lenses. So for my Ive been so disappointing by the lack of sharpness, overall image quality vs my crop cam, etc.
however canon can make this easier, would get my money. The current situation is truly horrible for pros and consumes alike spending thousands on gear that may or may not work well together.
Ill do whatever it takes to get the job done, but I truly despise just setting up fOcal- distances of 13 feet away from target, have to purchase long usb cords, need great amounts of light, etc. Its a pain in the ass (sometimes). I went full frame in November, and i have yet to be able to enjoy its benefits because of the ludicrous amount of time and particular setup needed to adjust lenses. So for my Ive been so disappointing by the lack of sharpness, overall image quality vs my crop cam, etc.
however canon can make this easier, would get my money. The current situation is truly horrible for pros and consumes alike spending thousands on gear that may or may not work well together.
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Loswr
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AvTvM said:
Not quite. One big difference between phase detect AF (PDAF) and contrast detect AF (CDAF) is that the phase difference provides data on both the magnitude of the change needed to achieve focus and the direction of the change, whereas CDAF does not provide directional information. So, for CDAF to work, it has to pick a direction and start to move the focusing elements, then determine whether the image becomes more or less focused - there's a 50/50 chance of getting it right (perhaps higher if the system guesses based on where the focusing group starts, e.g. if near the MFD, guess that focus needs to move away not toward, but it's still a guess). A big boost in speed when supplementing CDAF with on-sensor PDAF is that the focus starts moving in the right direction first, every time.
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