# 7DMKII Focus keeper rate ideas?



## Bigjezza (Nov 24, 2014)

Hi,
I have a 7D MKII. Let me just start with the fact that I understand that no AF is perfect. I also understand that f1.4. 2.8etc have a very small DOF

I've found that shooting one shot mode at a piece of typewritten paper in direct sunlight 50mm f1.4 I can expect maybe 7 or 8 out of 10 in focus at 100% (admittedly the 50mm 1.4 isn't razor sharp at that aperture) Is this to be expected? When viewed on a 28" 4K display other shots look fine until I get to about a 5CM of the display, and notice the focus is a bit off. Even with my 24-70 (Mark I) at 2.8 its maybe 70-90% spot on. Of course I didn't record my findings, just a casual chimp at the images and review on the screen.

Is it normal to think that at casual print sizes, maybe even upto 13X19, the oneshot AF is OK, but if I want to pixel peep or print bigger I'm better off MF with live view?

I went to the trouble of doing the test after I found it extremely difficult to get the iris/pupil in focus consistently. In fact with my kids I seem to get better results with AI Servo. Any tips there?

Howabout sports/action with a 70-200mm f2.8 IS USM II. Any idea on the keeper rate there? A number for me to strive to? I took it out the other day to the kids sports day and in AI Servo atleast 80% were great. Is that something to be proud/worried about??


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## Marsu42 (Nov 24, 2014)

Bigjezza said:


> I've found that shooting one shot mode at a piece of typewritten paper in direct sunlight 50mm f1.4 I can expect maybe 7 or 8 out of 10 in focus at 100% (admittedly the 50mm 1.4 isn't razor sharp at that aperture) Is this to be expected?



Af performance is a combination of camera body and lens, and choosing the old 50/1.4 which doesn't even have a real ring usm isn't your best choice there.



Bigjezza said:


> Is it normal to think that at casual print sizes, maybe even upto 13X19, the oneshot AF is OK, but if I want to pixel peep or print bigger I'm better off MF with live view?



Yes, Live view or precise/trained mf (with a viewfinder screen that allows you to see the dof) is your best bet and won't have the jitter of phase af that only has split seconds to make the decision. Note that for other cameras LV with focus peaking (Magic Lantern) is a tremendous help, but it's not available on the 7d2 (yet, if ever).



Bigjezza said:


> I went to the trouble of doing the test after I found it extremely difficult to get the iris/pupil in focus consistently. In fact with my kids I seem to get better results with AI Servo. Any tips there?



The actual focus point might be larger than what your vf shows, so getting pupils in focus that are a bit behind the eyebrows and cheeks is a challenge with thin dof.


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## jaayres20 (Nov 24, 2014)

The 50mm 1.4 is well known for focusing issues such as back focusing. It isn't a good lens to test the accuracy of a camera's AF. Get a lens that has great performing AF like the 24-70 or 70-200.


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## Bigjezza (Nov 24, 2014)

jaayres20 said:


> The 50mm 1.4 is well known for focusing issues such as back focusing. It isn't a good lens to test the accuracy of a camera's AF. Get a lens that has great performing AF like the 24-70 or 70-200.


I mentioned I had both of those in addition to the 50mm 

I'm after an idea on the expected consistency of the 7D Mark II with a 24-70 f2.8 (Mk I) and 70-200 IS f2.8 MkII in one shot outside on a target... Anyone tested theirs?


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## Sabaki (Nov 24, 2014)

I've just returned my 7Dii and will get a replacement in the next day or two. 

I spent some time analyzing my out of focus images and then the (almost) in focus images. The issue it seems is not a lens-to-body calibration scenario but rather the AF system that isn't doing its job right. 

I spoke at length to a senior Canon rep who advised that it sounds like an AF sensor malfunction. 

I'm crossing everything I can cross, hoping the next body is perfect.


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## Bundu (Nov 24, 2014)

Bigjezza said:


> Howabout sports/action with a 70-200mm f2.8 IS USM II. Any idea on the keeper rate there? A number for me to strive to? I took it out the other day to the kids sports day and in AI Servo atleast 80% were great. Is that something to be proud/worried about??



This is my first post on this forum. Got my 7Dm2 a week ago and read on this forum about focus problems on the mark2. Did some testing to try and determine if mine is a keeper.
Test conditions:
Completely overcast
Tv mode - 1000th shutter speed
auto iso - ranged from 1600 to 3200
Used spot + 4 focus points
10fps
AI Servo
A 7 year old child running flat out directly at me from 20 meters away (the only person that was willing to do a lot of running!)
I kept shooting till she ran past me.
Both lenses used micro adjusted
Three tests with 100-400 @ 400
Did not count shots at less than MFD
18/24 in focus
19/23 in focus
17/20 in focus
Three tests with 15-85 @ 85
all three tests all frames in focus - 27, 19, 24 frames
The 15-85 performed faultless and the 100-400 not. Is it because of the focal length or autofocus of the lens?
Is the performance of the 100-400 acceptable? I have noticed that with BIF (also overcast conditions) the keeper rate is higher. The birds did not fly strait at me but at a diagonal.
No problems whatsoever with one shot on stationary objects.
Had to AFMA the 100-400 with the 1.4III to -18

All in all I am very satisfied but do not know if the keeper rate is par for the 7Dm2. It is much better than my 70D, especially fast moving objects coming straight at me.

Thanks for a very informative forum - have been following it for more than a year now.
EDIT: She is 5 years old, not 7 - my granddaughter. Not exactly lightning fast!


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## Sella174 (Nov 24, 2014)

Shocking. Just simply shocking. Plus unbelievable.


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## Bundu (Nov 24, 2014)

This is shot with 15 point area AF. There was a break in the clouds with some backlighting - this series do not look as sharp as the ones without backlighting and 1 + 4 expanded autofocus. Any tips on what settings to use in this case?
Apologies, new to photography and need to learn as much as I can!!
Am I even posting in the correct section?

https://www.flickr.com/photos/[email protected]/sets/72157649043156158/


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## Bigjezza (Nov 24, 2014)

Sella174 said:


> Shocking. Just simply shocking. Plus unbelievable.


Care to elaborate?

I'm not 100% satisfied, and rather than send the body in for fruitless repairs I'm just wondering if I have anything to worry about...


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## Bundu (Nov 25, 2014)

Sella174 said:


> Shocking. Just simply shocking. Plus unbelievable.



Well, as stated, I am not good at this....... yet. I will get it better with some practise and I suppose adjusting/setting up the camera properly. I think that the problem I have on the photos might be using the 15 point area focus points - the camera might not be selecting the correct one? The first tests with 1+4 was much better.

You will see that both the 15-85 and 100-400 not perfectly in focus very time on the link below.

https://www.flickr.com/photos/bundutec/

tracking sens+2
accel/decel tracking +2
AF point switching 0
First image priority - focus
Second image priority - focus

I would also like to know if I have something to worry about.


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## Marsu42 (Nov 25, 2014)

Bundu said:


> I would also like to know if I have something to worry about.



No, it isn't. Just like with your shiny new car, you keep polishing it for the first weeks, carefully removing every tiny speck on the finish. With a new dslr, you keep pixel peeping and playing around with all settings.

*af: if you check the correct afma with the usual methods (diy or expensive software), it comes down to keeper rate and max. magnification. Tracking with thin depth of field is challenging for a phase af camera - with my 6d of your 20 kid shots, probably one would be in focus. Barely. Do check and experiment with the af settings in the firmware though, there are lots of options how the camera predicts the subject's movement.

* exposure: you didn't include the exif info in your flickr shots, so I cannot tell. But one reason for a slight blur (which you interpret as lack of sharpness) is too low shutter speed. That's the problem with a crop action camera - for fast movement, you need ~1/2000+ which results in high iso esp. in lower light. To check for this, simply use Tv with 1/8000s and look again 

Last not least, if your new toy would be perfect, how do you expect Canon to sell the 7d3  ?


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## Bigjezza (Nov 25, 2014)

Haha re the car made me laugh

Is it fair that in one shot at wide apertures its ok to miss a shot here and there? That's all I'm really wondering...


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## Bundu (Nov 25, 2014)

Marsu42 said:


> Bundu said:
> 
> 
> > I would also like to know if I have something to worry about.
> ...


Thanks, your comments helped me solve the issues I had.

I upped the shutter to 1000th sec, and the light had a huge influence. I took this 37 shot series with the light coming from above and slightly in front of her. All pictures sharp except for when she ran through deep shade when they got softer (almost in focus)


https://www.flickr.com/photos/bundutec/sets/72157647127523874/

31/37 with the light as it was plus deep shade is a win in my books!

Thanks again for your help, much appreciated!


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## Bundu (Nov 25, 2014)

Bigjezza said:


> Haha re the car made me laugh
> 
> Is it fair that in one shot at wide apertures its ok to miss a shot here and there? That's all I'm really wondering...


My 50 1.4 always soft at 1.4 and correctly focus only about 70% of the time. At f2.2 and smaller sharp and hit rate 90% plus.

I wanted to get the new car but - priorities!!!!


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## Bigjezza (Nov 25, 2014)

Bundu said:


> My 50 1.4 always soft at 1.4 and correctly focus only about 70% of the time. At f2.2 and smaller sharp and hit rate 90% plus.
> 
> I wanted to get the new car but - priorities!!!!


Thanks, that does set my mind at ease!
Can anyone comment on the 24-70 f2.8?


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## Marsu42 (Nov 25, 2014)

Bigjezza said:


> Can anyone comment on the 24-70 f2.8?



The mk2 has an improved af system vs. the mk1, but it's only usable with the latest camera bodies like 1dx and 5d3. But both are photo journalist lenses designed for fast and spot-on af. There's a lensrentals article on that, but it's not recent so it doesn't say anything about the 7d2.


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## Bigjezza (Nov 25, 2014)

At 2.8/24mm on the 24-70, 10 shots in One Shot, after racking each shot to macro I'm seeing maybe 2mm difference of the focal plane at a distance of 100cm. (Camera wasn't moving) Am I being stupid? Demanding too much? Maybe I've forgotten just how bad my kit lens with my 400D was 6 years ago and its long gone. I don't have anything to compare the 7DMKII + 24-70 to, except other lucky owners out there.


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## neuroanatomist (Nov 25, 2014)

Bigjezza said:


> At 2.8/24mm on the 24-70, 10 shots in One Shot, after racking each shot to macro I'm seeing maybe 2mm difference of the focal plane at a distance of 100cm. (Camera wasn't moving) Am I being stupid? Demanding too much? Maybe I've forgotten just how bad my kit lens with my 400D was 6 years ago and its long gone. I don't have anything to compare the 7DMKII + 24-70 to, except other lucky owners out there.



What are you focusing on for the above test?


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## Bigjezza (Nov 25, 2014)

I was afraid I'd get asked that
Tonight I'm scrutinising a jar of garlic with the camera sitting on the table... 8)
Oh and the 2mm difference (at a guess) isn't every shot... 8 are fine, 2 are off... with miniscule differences between the great ones.


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## candc (Nov 25, 2014)

Bundu said:


> Sella174 said:
> 
> 
> > Shocking. Just simply shocking. Plus unbelievable.
> ...



i don't think you need to have your af settings that high. i use -2,0,0 for bif and it is plenty fast enough for birds flying straight at me. i experimented with some higher settings and found it to be inconsistent as if the af was overreacting.


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## neuroanatomist (Nov 25, 2014)

Bigjezza said:


> I was afraid I'd get asked that
> Tonight I'm scrutinising a jar of garlic with the camera sitting on the table... 8)
> Oh and the 2mm difference (at a guess) isn't every shot... 8 are fine, 2 are off... with miniscule differences between the great ones.



That's a lot of garlic!

Reasonable target, though. I expect the variation you're seeing is normal. But it likely wouldn't hurt to call Canon and ask.


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## Bundu (Nov 25, 2014)

i don't think you need to have your af settings that high. i use -2,0,0 for bif and it is plenty fast enough for birds flying straight at me. i experimented with some higher settings and found it to be inconsistent as if the af was overreacting.
[/quote]

@candc Thank you, will definitely try those settings. There is just so much that you can change/fine tune......
A LOT to learn yet


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## Mt Spokane Photography (Nov 26, 2014)

AF systems in cameras are variable, and some lenses are more variable than others. The 50mm f/1.8 has a lot of variability, for example.


http://www.reikan.co.uk/focalweb/index.php/online-tools/lenscamera-information/


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## Sella174 (Nov 27, 2014)

Bigjezza said:


> Sella174 said:
> 
> 
> > Shocking. Just simply shocking. Plus unbelievable.
> ...



With current technology, for the 7DII to exhibit any form of AF problems is in my opinion totally unacceptable. This is a professional-grade camera and to expect any professional (where time equals money) to first calibrate the lens and camera combination is just plain wrong. What will happen if such a professional photographer rents (or borrows) a lens at the last moment, but must now spend an hour first to calibrate the combination? That is if he actually has his calibration tools with him!

Any professional-grade equipment must work 100% perfectly straight out of the box.


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## sanj (Nov 27, 2014)

Sella174 said:


> Bigjezza said:
> 
> 
> > Sella174 said:
> ...



In my experience (just Canon) it works almost always right out of the box. But I see your point. Is this just how cameras are or there is a QC issue? Is this not same with other brands of cameras?


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## Sella174 (Nov 27, 2014)

sanj said:


> In my experience (just Canon) it works almost always right out of the box. But I see your point. Is this just how cameras are or there is a QC issue? Is this not same with other brands of cameras?



I think it is more of a lowering-production-cost-through-lowering-quality-control situation. I never had any problems when using old Canon lenses on my old Canon cameras (film and digital). Only when I started purchasing/borrowing new lenses did I encounter focusing issues - all of which could have been corrected using AFMA, which my old cameras did not possess.


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## Valvebounce (Nov 27, 2014)

Hi Sella. 
I read posts like this and realise you either have bottomless pockets stuffed with money or lack a clear understanding of manufacturing tolerances. 
To have to calibrate a lens to a body is in my opinion not only acceptable but necessary. Each body and each lens are made to a plus or minus tolerance, measured in 0.01 or 0.001mm or even smaller! If both lens and body are middle limit, or out in complementary directions, ie the tolerances cancel all will be fine, if they are out in the other direction the tolerances are additive, I suspect each lens and each body is allowed + or - 10 AFMA POINTS and given this, a worst case scenario could see you needing all 20 AFMA points. (I don't know how many bits of a mm = 1 AFMA point)
To halve the tolerance range could add a significant percentage (I don't know how much so I won't quantify it) to the cost through extra manufacturing time and component scrapage! And then what you still have a tolerance, yes smaller, and still need to calibrate! So halve the tolerance again, can you see where this is going? Except the next reduction will cost more than the first reduction! 
Personally I'd sooner be able to afford a camera and lenses and calibrate than dream about equipment that is perfect, + or - 0.0000000mm and doesn't need calibration. 
14 yrs toolmaking working to tenths of a thousandth of an inch so I know a bit about increase of time with lower limits and scrapage rates. Conversely I don't know how much they would cost Canon as I don't work there! 

Cheers, Graham. 



Sella174 said:


> With current technology, for the 7DII to exhibit any form of AF problems is in my opinion totally unacceptable. This is a professional-grade camera and to expect any professional (where time equals money) to first calibrate the lens and camera combination is just plain wrong. What will happen if such a professional photographer rents (or borrows) a lens at the last moment, but must now spend an hour first to calibrate the combination? That is if he actually has his calibration tools with him!
> 
> Any professional-grade equipment must work 100% perfectly straight out of the box.


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## DominoDude (Nov 27, 2014)

To answer the question about how much is 1 unit on the AFMA scale: It is 1/8th of the current lens DoF at its widest aperture.

_Edit:_ Adding source to the above. Rudy W @ Canon, as described in this article -> http://www.learn.usa.canon.com/resources/articles/2011/af_microadjustment_article.shtml


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## Sella174 (Nov 27, 2014)

Valvebounce said:


> Hi Sella.



Howdy.



Valvebounce said:


> I read posts like this and realise you either have bottomless pockets stuffed with money *or lack a clear understanding of manufacturing tolerances.*



The bolded statement I do not understand, giving what you explain later on in the same post (quoted below).



Valvebounce said:


> To have to calibrate a lens to a body is in my opinion not only acceptable but necessary. Each body and each lens are made to a plus or minus tolerance, measured in 0.01 or 0.001mm or even smaller! If both lens and body are middle limit, or out in complementary directions, ie the tolerances cancel all will be fine, if they are out in the other direction the tolerances are additive, I suspect each lens and each body is allowed + or - 10 AFMA POINTS and given this, a worst case scenario could see you needing all 20 AFMA points. (I don't know how many bits of a mm = 1 AFMA point)
> To halve the tolerance range could add a significant percentage (I don't know how much so I won't quantify it) to the cost through extra manufacturing time and component scrapage! And then what you still have a tolerance, yes smaller, and still need to calibrate! So halve the tolerance again, can you see where this is going? Except the next reduction will cost more than the first reduction!
> [..]14 yrs toolmaking working to tenths of a thousandth of an inch so I know a bit about increase of time with lower limits and scrapage rates.[..]



True. Now apply it in reverse: Double the tolerance and you reduce the production cost by a significant percentage (unknown, as you stated) due to a lower scrapping rate.



Valvebounce said:


> Personally I'd sooner be able to afford a camera and lenses and calibrate than dream about equipment that is perfect, + or - 0.0000000mm and doesn't need calibration.



I partly agree. Canon, as an example, could use a larger tolerance criterion for the "Rebel" to reduce cost, but *must* then offer AFMA in those models. In "professional"-grade gear (both cameras and lenses), although also offering AFMA, it should not be necessary because of the more accurate machining of the mechanical/physical parts.

But that's just my opinion. I like good stuff that work 100% out of the box and don't mind paying extra for that convenience.


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## DominoDude (Nov 27, 2014)

I just showed this thread to a psychologist who's used to working with obstinate and "damaged" children; she almost wet herself and asked to borrow the bathroom. I don't know if it was from laughter, or if she got a glimpse of future revenues...


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## Marsu42 (Nov 27, 2014)

DominoDude said:


> I just showed this thread to a psychologist who's used to working with obstinate and "damaged" children; she almost wet herself and asked to borrow the bathroom. I don't know if it was from laughter, or if she got a glimpse of future revenues...


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## neuroanatomist (Nov 27, 2014)

Valvebounce said:


> I read posts like this and realise you either have bottomless pockets stuffed with money or lack a clear understanding of manufacturing tolerances.



+1 on the latter. The former wouldn't impact Canon's choices for manufacturing tolerances in general. 




Sella174 said:


> Any professional-grade equipment must work 100% perfectly straight out of the box.



That's a nice pipe dream. Cinematographers spend substantial time calibrating new lenses costing tens of thousands of dollars. 




Sella174 said:


> I think it is more of a lowering-production-cost-through-lowering-quality-control situation. I never had any problems when using old Canon lenses on my old Canon cameras (film and digital). Only when I started purchasing/borrowing new lenses did I encounter focusing issues - all of which could have been corrected using AFMA, which my old cameras did not possess.



It's more of a your-old-gear-lacked-sufficient-resolution-to-make-the-problems-evident situation.


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## Sella174 (Nov 27, 2014)

DominoDude said:


> I just showed this thread to a psychologist who's used to working with obstinate and "damaged" children; she almost wet herself and asked to borrow the bathroom. I don't know if it was from laughter, or if she got a glimpse of future revenues...



The trouble with "rules" on forums are that they only prohibit the ridicule of an individual, and not that of several (unnamed) individuals as a group.

That said, if your psychologist had that reaction from this thread, then she's obviously not ready for the real world.


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## Sella174 (Nov 27, 2014)

neuroanatomist said:


> Sella174 said:
> 
> 
> > Any professional-grade equipment must work 100% perfectly straight out of the box.
> ...



Are you a cinematographer that spends valuable time calibrating new lenses because the manufacturer didn't do it (properly)? Are you even a cinematographer? Unless you can answer yes to both questions, then what you wrote is hearsay and of absolutely no value whatsoever.



neuroanatomist said:


> Sella174 said:
> 
> 
> > I think it is more of a lowering-production-cost-through-lowering-quality-control situation. I never had any problems when using old Canon lenses on my old Canon cameras (film and digital). Only when I started purchasing/borrowing new lenses did I encounter focusing issues - all of which could have been corrected using AFMA, which my old cameras did not possess.
> ...



A yes, the old standard put-down. Give it rest, it's getting really old ... and totally redundant, because I do own new photographic gear ... just not Canon.


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## Valvebounce (Nov 27, 2014)

Hi Sella. 
I give a plus one on that! But then I don't think I need help from someone with ologist in their title, I could be wrong? 

Cheers, Graham. 



Sella174 said:


> That said, if your psychologist had that reaction from this thread, then she's obviously not ready for the real world.


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## Valvebounce (Nov 27, 2014)

Hi Domino Dude. 
I was aware of that, what I was referring to was how many 0.001mm manufacturing errors cause 1 AFMA unit of correction to be needed. 

Cheers, Graham. 




DominoDude said:


> To answer the question about how much is 1 unit on the AFMA scale: It is 1/8th of the current lens DoF at its widest aperture.
> 
> _Edit:_ Adding source to the above. Rudy W @ Canon, as described in this article -> http://www.learn.usa.canon.com/resources/articles/2011/af_microadjustment_article.shtml


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## neuroanatomist (Nov 27, 2014)

Sella174 said:


> neuroanatomist said:
> 
> 
> > Sella174 said:
> ...



Interesting that you interpret it as a put down, when it's a simple fact. With 35mm film and lower resolution dSLRs, subtle focus errors aren't as obvious. When the 7D came out, upgraders from the 40D claimed it was soft. In fact, the nearly double resolution of the sensor meant focus errors were much more evident (camera shake, too). The same is true with slower lenses. An 18 MP xxxD user may not notice slight backfocus with their f/3.5-5.6 zoom, but could with a 50/1.8.


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## neuroanatomist (Nov 27, 2014)

DominoDude said:


> To answer the question about how much is 1 unit on the AFMA scale: It is 1/8th of the current lens DoF at its widest aperture.
> 
> _Edit:_ Adding source to the above. Rudy W @ Canon, as described in this article -> http://www.learn.usa.canon.com/resources/articles/2011/af_microadjustment_article.shtml



Actually, Rudy Winston is incorrect. It's not 1/8th the depth of field, but 1/8th the depth of _focus_. The latter is the sensor-side equivalent of DoF, measured in microns. DoF changes with subject distance, depth of focus is relatively unaffected by subject distance. That distinction means the magnitude of the DoF shift for a given AFMA value changes with subject distance, which is the basis for the recommendation to calibrate at 25-50x the focal length unless you're consistently using the lens at a closer distance.


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## Marsu42 (Nov 27, 2014)

neuroanatomist said:


> Actually, Rudy Winston is incorrect. It's not 1/8th the depth of field, but 1/8th the depth of _focus_. The latter is the sensor-side equivalent of DoF, measured in microns. DoF changes with subject distance, depth of focus is relatively unaffected by subject distance.



Thanks for pointing this out, I was wondering about this very thing when I read the article.

Personally, I find the text to be a bit too much on the marketing talk side for my taste - and it's funny that the 2011 text points out that afma is totally fantastic and then they removed it from the 60d right after :->


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## Khnnielsen (Nov 27, 2014)

Sella174 said:


> neuroanatomist said:
> 
> 
> > Sella174 said:
> ...



I am not a cinematographer, but I can confirm that statement. When we buy gear at at the news station I used to work for, we also spend some time to calibrate the gear.

For example: We bought a $30,000 lens to go with our new $30,000 camera. Afterwards we had to spend some time adjusting backfocus in order to make sure, that the focus is constant throughout the zoom range.

And that is perfectly fine.


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## DominoDude (Nov 27, 2014)

Valvebounce said:


> Hi Domino Dude.
> I was aware of that, what I was referring to was how many 0.001mm manufacturing errors cause 1 AFMA unit of correction to be needed.
> 
> Cheers, Graham.
> ...



Yupp, I didn't doubt that, Graham. In order to keep it together I quoted you so the information came in a proper context.


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## DominoDude (Nov 27, 2014)

neuroanatomist said:


> DominoDude said:
> 
> 
> > To answer the question about how much is 1 unit on the AFMA scale: It is 1/8th of the current lens DoF at its widest aperture.
> ...



Ok, good clarification!
I'm not the one to go against Rudy, or you for that matter, on this subject.


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## dgatwood (Nov 27, 2014)

Valvebounce said:


> I read posts like this and realise you either have bottomless pockets stuffed with money or lack a clear understanding of manufacturing tolerances.



Either you have way more patience than I do or you're unfamiliar with the concept of testing and binning. Most modern electronics go through an extensive, fully automated testing and binning process, during which the manufacturer burns out fuses, programs PROMs, or whatever to compensate for manufacturing variation. For example, for many years, Intel would burn out defective cores and/or cache on their CPUs and change the product IDs so that they could sell CPUs that were partially defective. One core of that four-core CPU doesn't work? Burn out two cores and sell it as a two-core CPU. Cache on a Pentium chip doesn't work? Burn out the cache and sell it as a Celeron. And so on.

Similarly, when it comes to cameras, the tolerance isn't the main problem. The fact that *the user* has to calibrate it straight from the factory is the problem. In a sane world, Canon would connect the camera to a test rig using a fixed-focus lens and a target at a fixed distance. The camera would then compute its own base AFMA for each individual focus point in the camera, and would store that data permanently in an EPROM or flash part.

Similarly, for a lens, in an ideal world, Canon would attach it to a test rig consisting of a permanently mounted camera and target, and that modified camera would compute AFMA values for the lens at various zoom settings, and would then program the lens with a series of focus offsets, so that the lens would always focus correctly with zero AFMA (assuming the body was calibrated properly).

When you're talking about a lens that costs thousands of dollars, there is simply no excuse for having to manually calibrate the lens to compensate for significant copy variation. When a lens or camera arrives from the factory, it should have an AFMA adjustment of zero. It should "just work", and no lens/body combination should ever require more than about ±1 AFMA. Anything less than that level of consistency is just plain sloppy, IMO, and reflects a lack of adequate burn-in testing and factory calibration.


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## Marsu42 (Nov 28, 2014)

dgatwood said:


> For example, for many years, Intel would burn out defective cores and/or cache on their CPUs and change the product IDs so that they could sell CPUs that were partially defective. One core of that four-core CPU doesn't work? Burn out two cores and sell it as a two-core CPU. Cache on a Pentium chip doesn't work? Burn out the cache and sell it as a Celeron. And so on.



Afaik Intel & AMD also deactivate perfectly working cores/caches if the demand for cheaper cpus is higher than their production  ... that's why there are always rumors of "soft-unlocking" schemes with number key you can purchase from the manufacturer. Maybe a business model for Canon - unlock your 18mp camera to 24mp or 11ev to 13ev dynamic range?


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## Valvebounce (Nov 28, 2014)

Hi dgatwood. 

dgatwood link
Either you have way more patience than I do or you're unfamiliar with the concept of testing and binning. Most modern electronics go through an extensive, fully automated testing and binning process. 
This! :-[ :-X
Similarly, when it comes to cameras, the tolerance isn't the main problem. The fact that *the user* has to calibrate it straight from the factory is the problem. In a sane world, Canon would connect the camera to a test rig using a fixed-focus lens and a target at a fixed distance. The camera would then compute its own base AFMA for each individual focus point in the camera, and would store that data permanently in an EPROM or flash part.

Similarly, for a lens, in an ideal world, Canon would attach it to a test rig consisting of a permanently mounted camera and target, and that modified camera would compute AFMA values for the lens at various zoom settings, and would then program the lens with a series of focus offsets, so that the lens would always focus correctly with zero AFMA (assuming the body was calibrated properly).

When you're talking about a lens that costs thousands of dollars, there is simply no excuse for having to manually calibrate the lens to compensate for significant copy variation. When a lens or camera arrives from the factory, it should have an AFMA adjustment of zero. It should "just work", and no lens/body combination should ever require more than about ±1 AFMA. Anything less than that level of consistency is just plain sloppy, IMO, and reflects a lack of adequate burn-in testing and factory calibration.

I don't know what the scope is for automating this process, would it require quite a high human interaction to mount and dismount each item, thinking lens release button? 
I would imagine that each machine would be costly, plus use a lot of floor space, thinking test an 800mm lens, plus there would be a requirement for more than one of each, routine calibration etc, I still see the price climbing, though possibly by a much smaller margin. 
Again I find I am educated by the diverse range of knowledge here. Learning a little every day helps us know we are still alive! 

Cheers, Graham.


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## Sella174 (Nov 28, 2014)

Valvebounce said:


> I don't know what the scope is for automating this process, would it require quite *a high human interaction* to mount and dismount each item, thinking lens release button?



I am a big fan of job-creation. 



Valvebounce said:


> I would imagine that each machine would be costly, plus use a lot of floor space, thinking test an 800mm lens, plus there would be *a requirement for more than one of each*, routine calibration etc, I still see the price climbing, though possibly by a much smaller margin.



Canon either already has dedicated assembly lines for each and every lens in production; or Canon produces lenses in batches, adjusting the assembly line each time. (I remember reading an article on how Henschel built locomotives in the 1930's ... )


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## neuroanatomist (Nov 28, 2014)

Sella174 said:


> Valvebounce said:
> 
> 
> > I don't know what the scope is for automating this process, would it require quite *a high human interaction* to mount and dismount each item, thinking lens release button?
> ...



Most companies are not big fans of increased labor costs. Those costs are passed on to the consumer. So, I guess you're also a big fan of higher prices.


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## Sella174 (Nov 28, 2014)

neuroanatomist said:


> Sella174 said:
> 
> 
> > I am a big fan of job-creation.
> ...



I am also a fan of lower crime rates, which would lead to lower/zero insurance premiums ... thereby reducing the total cost of ownership.


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## dgatwood (Nov 29, 2014)

Valvebounce said:


> I don't know what the scope is for automating this process, would it require quite a high human interaction to mount and dismount each item, thinking lens release button?



I'd imagine a human would have to mount and dismount each item. I'd expect that to happen as part of basic QC testing anyway, though. I mean, they do at least connect each lens to a controller and perform an electronics test, right?


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## BLFPhoto (Nov 29, 2014)

Sella is unrealistic in his expectations and lacks perspective on design and manufacturing of high precision equipment. Only part of the AFMA equation is electronic. But the whole point is to adjust for minor mechanical tolerance deltas. The magnitude of those deltas is so minuscule as to make further refinement inordinately expensive. It is an acceptable level of risk that minor adjustments have to be made. Further, mechanical systems wear over time, even the best ones. AFMA allows Canon users to account for differences in their older gear as wear, or even minor dings or knocks that shift parts. Mechanical systems change over time. AFMA gives us a simple, painless way to account for that. 

And yes, real professionals in all fields dealing with tight tolerances have to calibrate their gear from time to time. I'm sure Neuro can talk long about calibration of scopes and scanning equipment....even multi-million dollar machines. 

Calibration is not indication of inherent lack of quality. I think we're lucky to have user calibration available. In the film days, we had to send our gear back to Canon, Nikon, etc. to fix minor focus problems. It was a PITA because it often meant sending bodies with the lenses.


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## neuroanatomist (Nov 29, 2014)

BLFPhoto said:


> Sella is unrealistic in his expectations and lacks perspective...



Yeah, my favorite from this thread was the expectation that a pro renting some gear should not have to calibrate it. I guess rental houses are supposed to have the same calibration gear Canon should have, then have all rentals hand-delivered by white-glove couriers lest a careless UPS handler drop a box. Oh, and they should do all that without passing the costs along to the customer. 

Ok, that's actually my second favorite. Top honors go to lower crime rates leading to zero insurance premiums. : :


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## Sella174 (Nov 29, 2014)

BLFPhoto said:


> Sella is unrealistic in his expectations ...



Not really, given the current trend in consumer protection legislation.




BLFPhoto said:


> ... and lacks perspective on design and manufacturing of high precision equipment.



When you allow a large tolerance variation in your products, you are no longer manufacturing high precision equipment.




BLFPhoto said:


> AFMA allows Canon users to account for differences in their older gear as wear, or even minor dings or knocks that shift parts. ... AFMA gives us a simple, painless way to account for that.



There is no way that AFMA will ever allow you to adjust for a shifted lens element.

Also, your basic statement is only one-third correct. Old'ish Canon cameras and all new "Rebels" do not offer AFMA. Thus, only if you own a camera that does offer AFMA can you use it ... and this is what fraction of Canon DSLR camera owners? (At least Sigma offers users that docking pod thing for calibrating their lenses, irrespective of the Canon camera owned.)




BLFPhoto said:


> I'm sure Neuro can talk long about calibration of scopes and scanning equipment....even multi-million dollar machines.



I'm sure *neuroanatomist* can talk long about many other things as well.




BLFPhoto said:


> Calibration is not indication of inherent lack of quality.



No, calibration is not an indication of a lack quality, rather the extent to which new equipment needs to be calibrated is an indication of the lack of quality control on the part of the manufacturer.


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## Sella174 (Nov 29, 2014)

neuroanatomist said:


> Yeah, my favorite from this thread was the expectation that a pro renting some gear should not have to calibrate it.



I do believe that specifically I wrote (bold added):



Sella174 said:


> What will happen if such a professional photographer rents (or borrows) a lens *at the last moment*, but must now spend an hour first to calibrate the combination?



Obviously you've never had equipment croak on you at an event and then have some nice person loan you his "backup" gear. Or _vice versa_.




neuroanatomist said:


> I guess rental houses are supposed to have the same calibration gear Canon should have, then have all rentals hand-delivered by white-glove couriers lest a careless UPS handler drop a box.



Personally, I fully expect a reputable rental company to check each and every lens for faults upon receiving it back. Would you be amicable if that super-great lens you rented arrives the afternoon before the big event and it cannot focus properly ... no matter how much you AFMA, huh?




neuroanatomist said:


> Oh, and they should do all that without passing the costs along to the customer.



Why not. As the saying goes: you pay peanuts, you hire monkeys.




neuroanatomist said:


> Ok, that's actually my second favorite. Top honors go to lower crime rates leading to zero insurance premiums.



Understandably my original statement was rather a difficult concept to grasp, seeing as it combines legal theory and social science, plus borrowing elements from psychology. However, I am glad it at least had some entertainment value ... granted I'm no Bill Nye.


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## neuroanatomist (Nov 29, 2014)

Sella174 said:


> neuroanatomist said:
> 
> 
> > Yeah, my favorite from this thread was the expectation that a pro renting some gear should not have to calibrate it.
> ...



Failing to plan is planning to fail. If a professional rents something at the last moment, not allowing time to test out the equipment before it's needed, said professional is not very competent. As for having something fail at an event and needing to borrow a replacement on the spot, again that's failing to plan and thus planning to fail. One should always have a backup – already tested and calibrated – for critical equipment needed to carry out the job properly. 

I'm not a professional photographer, so I haven't had those issues in that context. I can say that as a scientist running time-critical experiments, I've had equipment failures over the years...but none of them have resulted in failed experiments, because I always ensure there is backup equipment available...pre-tested and calibrated so it can be immediately swapped in if needed. That's just proper planning...something done by good professionals in any field. 




Sella174 said:


> neuroanatomist said:
> 
> 
> > I guess rental houses are supposed to have the same calibration gear Canon should have, then have all rentals hand-delivered by white-glove couriers lest a careless UPS handler drop a box.
> ...



Of course they should check it for proper operation before it's sent out. What you suggested is they they should somehow ensure that the gear they send me functions perfectly with my own gear with which I plan to use the rental(s), and that's beyond their control. For example, I once dropped my 5DII and while the camera was cosmetically and functionally okay after the fall, all of my AFMA values shifted 10 units negative. How is the rental company going to account for that? 

As for it arriving the afternoon before the big event, I wouldn't be so foolish as to rent something and have it arrive the day before I needed it. Rather, I'd have it arrive with sufficient time to test it (even if it left the rental house in perfect condition, shipping damage can occur), and still have a replacement shipped out to arrive before the event, if needed. Failing to plan is planning to fail, remember?

Judging by your comments above, you are willing to accept or excuse a lack of proper planning (i.e., incompetence) by yourself or professionals you may choose to hire. It that works for you, fine...it doesn't work for me. 




Sella174 said:


> neuroanatomist said:
> 
> 
> > Ok, that's actually my second favorite. Top honors go to lower crime rates leading to zero insurance premiums.
> ...



The concept was simple to grasp, the problem is your grasp on reality. Lower crime rates already lead to lower insurance premiums – localized crime rates, along with localized claim filing rates, are the major drivers for geographical variation in insurance premiums. You did suggest lower premiums, but also zero premiums. For-profit insurance companies giving free coverage? Completely unrealistic. 

Also, coverage for photography gear (at least in the US) is rarely for theft only. Loss and unintentional damage are also covered by those policies, and low crime rates won't prevent people from dropping their gear.


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## sanj (Nov 29, 2014)

I am a cinematographer working with top end gear. Before start of every movie my 2nd AC visits the rental house with test charts and checks focus distance with tape measure vs eye focus, zoom lens calibration, flare etc to see if all is ok. OCCASIONALLY he has to ask the rental house to change a lens. This is a perfectly normal procedure in the industry.

All good rental houses have a calibration bench and a tech works on it non stop calibrating lenses. 

But are normal consumers supposed to do this with their small cameras is the question….


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## neuroanatomist (Nov 29, 2014)

sanj said:


> But are normal consumers supposed to do this with their small cameras is the question….



What's a 'normal consumer'? I'd say a typical consumer buys an entry-level dSLR with the kit lens(es). An APS-C sensor with an f/5.6 lens means DoF is deep enough to mask focus errors even if the user is pixel peeping (which many won't). 

People who want the best possible performance from high-end gear should expect to put in some effort to achieve that goal.


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## Bigjezza (Nov 30, 2014)

Woah, interesting discussion going on here. I had no idea when I started this thread lol.

I like to think of these L lenses and bodies as suitable for professionals, but not perfect. I'm happy with the prices now without additional QC and cost. What I mean is the average joe with a bit of saving can afford the exact same system as the 'togs use on the sidelines at any pro sports game. Now think about movies. Independent film makers aren't exactly shooting with the same stuff as Hollywood, are they?

So anyway my issue isn't the body. Its my lens...

I discovered I can check the consistency simply by performing AF and looking at the scale on the lens. If I had thought of this a few weeks ago my shutter count would be a lot less :-[ I let it focus in live view or MF and make a mental note on the scale of where it landed.

What's happening is at 50-70mm on the 24-70 its pretty much hitting the same spot on the scale every time it AF's. I lost count of good AF after 50 goes... Cool. Between 24-50(ish)mm 5 shots here, 1 there, 6 here, 1 there, etc... If the regular AF falls on that spot, all good. Which it does above 50mm. 

For a minute I thought in horror maybe its my shiny new 7DMKII... So I got the 70-200 f2.8 IS II and performed the same test at 70 and 200. It mis focussed 1 out of about 50 goes. I can live with that, until someone comes along and convinces me that is not acceptable 

I have worried about this for about 2 weeks, doing tests ad hoc time permitting. I came to this conclusion about an hour ago after spending a day at the zoo and in the back yard learning that under 50mm was bizarre.

So I can actually trust this body at f2.8! Now to find a good repair place, and a f1.2 lens haha...


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## racebit (Dec 1, 2014)

neuroanatomist said:


> People who want the best possible performance from high-end gear should expect to put in some effort to achieve that goal.



It is unfortunate that Canon did not use DPAF to assist PDAF calibration. That would be one of the most important features of DPAF. When 70D did not include it, I though it was because it was first iteration of DPAF, but I was confident it would present on following iterations. Very sad it is not.
The disadvantage of DPAF vs PDAF is speed, that is why we still need PDAF, but we do not need speed to calibrate.

So, yes I agree we should put some effort into calibrating the lens, but Canon should put some effort too, and Canon did nothing to assist the procedure and left all effort to the user.


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## Valvebounce (Dec 1, 2014)

Hi racebit. 
Wouldn't this have already been possible on anything that has live view focus? Or is DPAF significantly more accurate, I thought DPAF benefit was speed of live view focus? 

Cheers, Graham. 



racebit said:


> neuroanatomist said:
> 
> 
> > People who want the best possible performance from high-end gear should expect to put in some effort to achieve that goal.
> ...


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## Bigjezza (Dec 2, 2014)

I had one situation the other week that DPAF failed over PDAF. It was a galvinised steel pole sticking up and the DPAF just wouldn't lock on it no matter what, even after magnifying. Oddly enough spot PDAF nailed it. Can the 7DMKII still do contrast detect AF?


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## Marsu42 (Dec 2, 2014)

Bigjezza said:


> Can the 7DMKII still do contrast detect AF?



Afaik af in live view is *always* contrast detect (supported), the phase detect pixels just give the contrast af hints where to go? This is exactly what I think...



Valvebounce said:


> I thought DPAF benefit was speed of live view focus?



.. or has this tech changed from the Rebels to the newest dual pixel af on the 7d2?


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## racebit (Dec 2, 2014)

Well Graham, yes, you are right, standard contrast detection can be used to calibrate PDAF.
But I think DPAF can achieve a more precise focus. The reason being that DPAF not only tells which direction is right focus (so faster focus), but also that right focus is achieved when you get balanced data from both pixels. So it provides a real focus confirmation. Even if the DPAF were not more accurate than CD, the sum of the two sources of data (DP and CD) should provide a more accurate focusing.
Again, you are right, automatic AFMA should have been there before DPAF. But with camera processing power increasing greatly at each generation, there is less excuse for it not being there.
I think I will buy a 7D2, but DPAF turned out to be a useless piece of crap to me. I wanted DPAF for two purposes, and it does none of them:
1. Assist manual focus lenses (and telescopes, no electronics).
2. Assist AFMA.
And again point 1 could be made with CD, although not as practical, giving only a contrast number instead of a focus direction. But I would welcome the contrast number anyway. So easy to implement, no reason to not be there.
Furthermore DPAF can only be used with Canon lenses and not all of them. Ridiculous, when the concept should be used even with manual lenses.
So, again, to me DPAF is a useless piece of crap. Sorry to say that. I will still buy the 7D2 anyway, but obviously not for the DPAF.

Pedro



Valvebounce said:


> Hi racebit.
> Wouldn't this have already been possible on anything that has live view focus? Or is DPAF significantly more accurate, I thought DPAF benefit was speed of live view focus?
> 
> Cheers, Graham.
> ...


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## Valvebounce (Dec 2, 2014)

Hi Pedro. 
Ok I now have a better idea of DPAF. So yes it would improve AFMA accuracy if it were enabled, and like you I don't understand why it is not. 
As for it not working on all Canon lenses, or any 3rd party lenses that seems ludicrous to me but I guess there may be technical reasons for this and they're not just being bloody minded. :'(

Cheers, Graham. 



racebit said:


> Well Graham, yes, you are right, standard contrast detection can be used to calibrate PDAF.
> 
> Snip snip.
> 
> ...


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