DotTune: Video Tutorial for AF tuning without photographs

[Northstar]

Nice video, I look forward to trying out dot tune.

[PhotoCat]

Very informative video and it took a lot of work to make it.
Thanks horshack for sharing this idea freely.
Highly appreciated. I will definitely give that a try.

[Northstar]

Very informative video and it took a lot of work to make it.
Thanks horshack for sharing this idea freely.
Highly appreciated. I will definitely give that a try.

I agree about sharing the idea freely BUT...as Horshack, once he knew the answer to the afma question he had to scream to the dslr world....OH OH OH....OH OH OH OHH OHH OHH!!

Welcome back Kotter.

[PhotoCat]

It worked on my 5D2 and 85/1.8 combo! This is the first time I have any consistent results from AFMA!
A value of -10 makes my full length portrait much sharper at f1.8 at a shooting distance of 12 to 17.5 feet.

A -10 AFMA would however make any shots less then 10 feet away slightly OOF and I am not surprised as this appears to be one limitation of Canon's AFMA implementation to date IMHO.  Canon's AFMA appears subject distance dependent.
For that kind of shorter distance (< 10 feet), I needed to turn off AFMA to get a sharp image.

It seems that Canon's factory lens calibration is much better than can be achieved by on-camera AFMA, as far
as distance dependence is concerned.

Now sigma has the USB lens dock for focus calibration, I hope Canon would catch up quickly by offering a Canon USB lens dock so we can perform factory quality lens calibration at home...

[PhotoCat]

Mmm... forget about the lens dock... Canon can do better by incorporating the lens calibration software right inside EOS Utility and calibrate the lens while it is attached to the specific camera body...  It is 100x better than a lens dock!

[horshack]

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!	Small | Large

[East Wind Photography]

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]

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]

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.