DotTune AFMA (dot_tune.mo)

[msadat]

thx alex that worked, now i see if i can get consistent set of number for sigma 50mm 1.4 and canon 85mm 1.2

[msowsun]

I have a 5D Mk II running v2.3.NEXT.2013Mar19 

While running Dot Tune AFMA with my 70-200mm 2.8 IS II, I would sometimes get a bug: Each and every MA box would light up  during the test on all 4 passes. (even with -100..+100 selected). This would result in a new AFMA of "0" and an Error message "Double-check the focus target".  This would happen a few times in a row. Changing Focus Targets, distance, and lighting, had no effect. I would then exit the program, reboot the camera, and try various other things until it went away.  This only happened a few times and I am not even sure how I was able to correct it.

Any thoughts on what was going on?

SOLVED...  Before running Dot Tune AFMA, go into the Canon AFMA menu and set a random MA value for the lens before you run ML Dot Tune AFMA. If you don't you may get the type of error I reported.....   

[Francis]

Are you using the widest aperture?

[msowsun]

Yes, the camera was set wide open. But even if it wasn't, the lens is always wide open when focusing, so it shouldn't make any difference.   

[horshack]

I have a 5D Mk II running v2.3.NEXT.2013Mar19 

While running Dot Tune AFMA with 200mm or longer lenses I would sometimes get a bug: Each and every MA box would light up green during the test on all 4 passes. (even with -100..+100 selected). This would result in a new AFMA of "0" and an Error message "Double-check the focus target".  This would happen a few times in a row. Changing Focus Targets, distance, and lighting, had no effect. I would then exit the program, reboot the camera, and try various other things until it went away.  This only happened a few times and I am not even sure how I was able to correct it.

Any thoughts on what was going on?

Your symptom sounds like the AF tune value being scaled by the ML logic wasn't being applied/utilized by the camera's AF logic for some reason. Please report back if you're able to reproduce this.

[achangsta]

I have a 5D Mk II running v2.3.NEXT.2013Mar19 

While running Dot Tune AFMA with 200mm or longer lenses I would sometimes get a bug: Each and every MA box would light up green during the test on all 4 passes. (even with -100..+100 selected). This would result in a new AFMA of "0" and an Error message "Double-check the focus target".  This would happen a few times in a row. Changing Focus Targets, distance, and lighting, had no effect. I would then exit the program, reboot the camera, and try various other things until it went away.  This only happened a few times and I am not even sure how I was able to correct it.

Any thoughts on what was going on?

I tested DOTtune yesterday and I had the same problem with all three of my zoom lenses. Every single box had a focus confirmation for all 4 passes, even with -100..+100. I kept getting an AFMA of 0. I tried multiple times with each lens, both on the wide and tele. I'm using the 5d3 with an unreleased ML version that has DOTtune.

Any ideas??

Here's a rundown of the procedure I used:
1. Put chart on a wall and positioned the camera at 50x the focal length (e.g., 24mm at 1200mm or 47.24in)
2. Manual focus and widest aperture on lens; single shot and single point AF on camera
3. Manual focus using LiveView with AFMA value "0"
4. Run DOTtune in ML
5. Every box gives focus confirmation, new AFMA of "0"
6. Repeated for -40 to +40 and -100 to +100, same results
7. Repeated for wide and tele on every lens, same results...

[msowsun]

I had the problem with my 70-200mm 2.8 IS II with, and without, the 1.4x II. I only tried it at 200mm or 280mm. My other lenses never had a problem and I haven't been able to replicate the "Bug" since that first day. 

Which lenses did you have problems with?

[achangsta]

Sorry, double post. How do you delete a post?

The lenses I used are:
Canon 16-35mm f/2.8
Canon 24-70mm f/2.8
Canon 70-200mm f/2.8

[msowsun]

I did reload ML and also went from the March 19 to March 24 Nightly Build, and haven't had it happen again.

[msowsun]

I bought a new 17-40mm 4.0 today and it will not run AFMA.  Each time I run it all the squares light up and the AFMA result is of course "0".

My other lenses are all fine: 40mm 2.8, 50mm 1.8, 50mm 1.4, 24-105mm, including the 70-200mm 2.8 IS II which originally gave me problems.

Just the new 17-40mm is doing it, and it's done it about 10 times in a row. I tried it at different distances and with different targets. I also formatted the card and reloaded ML 2.3 with March 24 Nightly Build. Nothing helps.

[msowsun]

Well I got the 17-40 to work now..... and here is what  I did....


I took my CF card and formatted it my computer. I then inserted into my 5D Mk II to get the Canon software on it.
Then I put it back into my computer and installed ML 2.3 and then back in the 5D Mk II and installed ML 2.3 to the camera.
Back in the computer and added 2.3.Next.2013.Mar29 and then ran that in the camera, and now it works!

FALSE ALARM! It ran once and now it is doing the same thing again.....     I probably didn't have a proper focus.

[msowsun]

Update....

If I run AFMA mode as "All Lenses" then it runs normally with the 17-40.

[msowsun]

Does it help if you change the AFMA value from Canon menus first?

I just tried that and YES it works now! 

I guess it's still a Bug, but with an easy work around.
 

[1%]

You have to "register" the lens from the canon menu first to use W/T.. a value in the property changes to 1. If you don't do that results may vary as you've seen.

[msowsun]

Sorry, what is W/T ?  I always register the lens for Peripheral Illumination Correction but hadn't done it yet for the 17-40.

[Francis]

Wide and Telephoto. Some models allow adjusting the AFMA for both ends of the zoom range.

[msowsun]

The 7D and 5D Mk II don't have the Wide/Tele MicroAdjust option.  I think only the 6D, 5D Mk III and 1Dx have it.

[pulsar124]

I have another suggestion for dot-tune improvement. How about an optional 'cumulative' mode? Specifically, when testing zoom lenses or/and lenses at different distances from the target, one often gets different good dot-tune intervals for MA. E.g, my Sigma 17-50  has MA say -15...-2 at 17mm, and -5...+5 at 50mm. The current dot-tune implementation is not very useful for finding a single compromise value for MA which would be acceptable at any FL. All I get is either one FL or the other FL values; the important interval width information is discarded. But if ML had a cumulative mode, and let me run dot-tune a few times at different FL, and then computed a single compromise value taking into account interval widths, that would be very helpful. In my example, the common MA interval for both FL is -5...-2; the compromise value would be either -4 or -3. At the very least, you could make ML print out the intreval at the end of every calibration; the compromise value would be computed manually.

[engardeknave]

Maybe ML could dynamically set afma to predetermined values as the lens is focused.

[Francis]

Maybe ML could dynamically set afma to predetermined values as the lens is focused.

Canon firmware only reports focal distances in Liveview, which does not use the 'tuned' autofocus system.

[pulsar124]

So, no comments about my "cumulative mode" suggestion (see two posts above)? It wouldn't be too hard to implement (I think), and zoom lens owners would really appreciate it.

[Francis]

Sounds like you already know how to do it. Run the calibration at a few focal lengths and compute the average. The mean of the means should be close enough.

[pulsar124]

No, I am not talking about means, I am talking about overlapping intervals, these are different things. In the case of say [-16...0] at one FL end and [-2...+2] at the other, the cumulative approach would yield MA=-1. The mean of means would yield MA=-4 - definitely bad number, as it is outside of the good MA values for the second FL.

[horshack]

I have another suggestion for dot-tune improvement. How about an optional 'cumulative' mode? Specifically, when testing zoom lenses or/and lenses at different distances from the target, one often gets different good dot-tune intervals for MA. E.g, my Sigma 17-50  has MA say -15...-2 at 17mm, and -5...+5 at 50mm. The current dot-tune implementation is not very useful for finding a single compromise value for MA which would be acceptable at any FL. All I get is either one FL or the other FL values; the important interval width information is discarded. But if ML had a cumulative mode, and let me run dot-tune a few times at different FL, and then computed a single compromise value taking into account interval widths, that would be very helpful. In my example, the common MA interval for both FL is -5...-2; the compromise value would be either -4 or -3. At the very least, you could make ML print out the intreval at the end of every calibration; the compromise value would be computed manually.

Generally speaking the width of the confirmed tune range is a function of FL, subject distance and DOF and may not yield any additional information useful for producing a composite tune value for multiple FLs. Experiments would need to be performed to prove otherwise. I'll try to experiment with it next week.

[pulsar124]

Thanks - I am also experimenting with this right now.

Actually, one simple ML modification would accomplish most of what I'm asking for: if at the end of calibration ML would print on the screen not just the median value, but the good interval as well. Then one can do any kind of calculations with these numbers.

I know the good interval is a function of the distance - but so is the median MA value as well, for many lenses. As a result, MA calibration is normally done at the typical distances the lens is used, hence the good interval information should still be valid.

The essence of my original point is that not just the median, but the whole MA interval information is valuable, and should not be discarded. The whole interval corresponds to MA values deemed "as good as it gets" by the AF system of the camera (or at the very least as "sufficiently good"). I'd expect this interval being wider at shortest FL of zoom lens (because of deeper DoF), and more narrow at the longer end (more shallow DoF). Using my approach to find the optimal MA value would take this DoF behaviour into account, and allow you to find the MA value where AF deviation from the perfect focus is comparable (in DoF units) at any focal length.

Here is actually another possibility - even more accurate way to find the optimal MA for a zoom which has different MA and different interval widths at the opposite FL ends perhaps would be to assume the interval width (or rather half-width) as a std (standard deviation), and the compute the optimal MA as a weighted average, using the standard formula:

<MA> = [MA1/(del1**2) + MA2/(del2**2)] / [1/del1**2 + 1/del2**2].

All these different approaches can be tested, if only ML could print the good MA range at the end of calibration.