DotTune: Video Tutorial for AF tuning without photographs

[horshack]

Magic Lantern DotTune

FYI, the guys over at Magic Lantern have implemented an automated version of DotTune. You establish critical focus in LV the same as the usual DotTune method but then ML takes over and automatically scans the AF tune range to find the optimal value, and saves the value into the camera when done.

Here's a video demonstrating the alpha version of the feature running on my 5DM3:
DotTune coming to Magic Lantern!

 

[East Wind Photography]

Re: Magic Lantern DotTune

Will the AFMA value be retained if you remove ML and boot in native mode? ML is great but most versions still are not stable enough to use in critical shoots.

FYI, the guys over at Magic Lantern have implemented an automated version of DotTune. You establish critical focus in LV the same as the usual DotTune method but then ML takes over and automatically scans the AF tune range to find the optimal value, and saves the value into the camera when done.

Here's a video demonstrating the alpha version of the feature running on my 5DM3:
DotTune coming to Magic Lantern!

 

[horshack]

Re: Magic Lantern DotTune

Will the AFMA value be retained if you remove ML and boot in native mode? ML is great but most versions still are not stable enough to use in critical shoots.

Yep, it stores the calculated AFMA value in the same non-volatile memory position that the Canon firmware uses, so it will be persistent across power cycles and available even if you're not using ML.

 

[East Wind Photography]

Re: Magic Lantern DotTune

Congratulations! This is an excellent first step which will only improve going forward.

Will the AFMA value be retained if you remove ML and boot in native mode? ML is great but most versions still are not stable enough to use in critical shoots.

Yep, it stores the calculated AFMA value in the same non-volatile memory position that the Canon firmware uses, so it will be persistent across power cycles and available even if you're not using ML.

 

[digital paradise]

Well DotTune did confirm my suspicions. First off the using the new method where you stop at the instant AF acquisition worked good. It only made a difference for +3 to +2 for my final MFA but still much easier to work with.

It did confirm my new 70 to 200 2.8 II is way out at 200. It still beeps at +20 and stops beeping at +7 which put me around +14. That was confirmed by real world shots. Major difference at 0 and +14. Not even thinking about a work around - it is off to Canon.

 

[East Wind Photography]

OMG, before you spend $$$ shipping your stuff back to Canon + insurance, You better validate your results with a sloped ruler test. Dont rely too heavily on the DT results as the AF detect systems are not very accurate. It may get you in the ball park but unless you have a way to categorically verify your setting, it could be way off. I cant get DT to give me an accurate AFMA. When I compare with my lensalign target it's off by 8 AFMA and for that lens it's a full DOF.

More work needs to be done to make the AF detect system accurate and reliable.

Well DotTune did confirm my suspicions. First off the using the new method where you stop at the instant AF acquisition worked good. It only made a difference for +3 to +2 for my final MFA but still much easier to work with.

It did confirm my new 70 to 200 2.8 II is way out at 200. It still beeps at +20 and stops beeping at +7 which put me around +14. That was confirmed by real world shots. Major difference at 0 and +14. Not even thinking about a work around - it is off to Canon.

 

[digital paradise]

There is no doubt that lens is out. My shooting partner has one, he tried it and found it was soft. I noticed it right away after I got it. After comparing shots @0 and +14 you could see +14 was much sharper. +14 is unacceptable for what I paid. I appreciate your support but I'm sending it in just for the piece of mind alone.

OMG, before you spend $$$ shipping your stuff back to Canon + insurance, You better validate your results with a sloped ruler test. Dont rely too heavily on the DT results as the AF detect systems are not very accurate. It may get you in the ball park but unless you have a way to categorically verify your setting, it could be way off. I cant get DT to give me an accurate AFMA. When I compare with my lensalign target it's off by 8 AFMA and for that lens it's a full DOF.

More work needs to be done to make the AF detect system accurate and reliable.

Well DotTune did confirm my suspicions. First off the using the new method where you stop at the instant AF acquisition worked good. It only made a difference for +3 to +2 for my final MFA but still much easier to work with.



It did confirm my new 70 to 200 2.8 II is way out at 200. It still beeps at +20 and stops beeping at +7 which put me around +14. That was confirmed by real world shots. Major difference at 0 and +14. Not even thinking about a work around - it is off to Canon.

 

[digital paradise]

Oh yes. I tried DotTune with my 24-70 II using the new focus acquisition method. -1 @ 24 and +1 @ 70 which basically matched my real world results I'm getting.

 

[digital paradise]

I would love to see an app for this. I don't really want to download ML at this point. Something that worked like this. It could do several LV readings, establish the best one and then run through the - + routine several times. You could do this anywhere in minutes.

http://www.shutterbugremote.com

 

[tomscott]

What I dont get is that if you are using a zoom is where to AFMA. I use a 24-105mm and according to LR I use it all across the zoom range. Ive read that with zooms your better off AFMA'ing at the tele end so say a 24-105 at 105 or 70-200mm at 200.

Also if you AFMA from the distance calculated does that mean at other distances the lens wont operate as well. Im a bit confused.

Seems like a complete pain.

 

[digital paradise]

You are supposed to MFA at the longest focal length. Probably to the second question. If you have a camera like the 5D3 you are covered at both ends.

 

[tomscott]

So you can have 2 AFMA values for one lens on the 5DMKIII? For wide and tele?

 

[East Wind Photography]

Only for zooms and only for the full wide and full tele positions. No guarantee that an extrapolated AFMA will work for in between values. However because your DOF is deeper at wide angles it's "less" important as at full tele.

So depending on how far off the AFMA is through the range, you might be able to get away with using an AFMA value for the wide setting that is more in tune with one of your most used MID ranges and let DOF mask the error wide open.

Depends a lot on the lens and how far off the AFMA is through the zoom range. If the AFMA swings wildly through the zoom range it might not be possible to fudge the AFMA.

So you can have 2 AFMA values for one lens on the 5DMKIII? For wide and tele?

 

[tomscott]

Ok great thanks for the information!

 

[digital paradise]

My new 70-200 is plus 2 @ 70 and plus 18 @ 200. It is go ing to Canon