Home · Register · Join Upload & Sell

Moderated by: Fred Miranda
Username  

  New fredmiranda.com Mobile Site
  New Feature: SMS Notification alert
  New Feature: Buy & Sell Watchlist
  

FM Forums | Canon Forum | Join Upload & Sell

1       2       3              35              37       38       end
  

Dot-Tune: Autofocus Fine Tuning in under 5 minutes

  
 
Dj R
Offline
• • • •
Upload & Sell: Off
p.36 #1 · p.36 #1 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


snapsy wrote:
Thanks Fred. Irrespective of the AF tuning method used, I've found that for large-aperture primes it's best to tune for far distances rather than shorter. There's an asymmetrical relationship here - if I tune for short distances then far distances are OOF with that tune value. However if I tune for far distances then short distances still work fine. I have a few theories as to why this is but I haven't spent the time to prove them out yet.


How far is far? What distance do you feel is best. For, let's say primes 28, 58, 85 ?



Jun 07, 2016 at 10:23 PM
snapsy
Online
• • • • • •
Upload & Sell: On
p.36 #2 · p.36 #2 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


Dj R wrote:
How far is far? What distance do you feel is best. For, let's say primes 28, 58, 85 ?


I mostly tune at infinity now.



Jun 07, 2016 at 10:25 PM
Dj R
Offline
• • • •
Upload & Sell: Off
p.36 #3 · p.36 #3 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


Recently found a comment suggesting running it at 50x focal length



Jun 07, 2016 at 10:38 PM
snapsy
Online
• • • • • •
Upload & Sell: On
p.36 #4 · p.36 #4 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


Dj R wrote:
Recently found a comment suggesting running it at 50x focal length

That's the prevailing wisdom. I've had much better success tuning at infinity, esp for lenses with distance-specific tuning variability.



Jun 07, 2016 at 11:01 PM
gschlact
Offline
• • • •
Upload & Sell: Off
p.36 #5 · p.36 #5 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


snapsy wrote:
That's the prevailing wisdom. I've had much better success tuning at infinity, esp for lenses with distance-specific tuning variability.


Snapsy,
Your suggestion is a great anecdotal Tip. In the past most people that observed distance specific mfa tuning chose instead their most common distance. Hearing your claim that tuning at infiniti mostly overcome distance specificity is encouraging.

Guy
gschlact



Jun 08, 2016 at 03:39 PM
armd
Offline
• • • •
Upload & Sell: On
p.36 #6 · p.36 #6 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


Does anyone still use the Dot Tune method and if so, how consistent are their results? I decided to give it a whirl yesterday as spring has come to our area and set up a series of tests with a couple of my lenses and my 5dmkIII. No problem with the primes, 50 and 85 and neither required much adjustment with that body, +1 and it seemed reproducible and reasonably accurate. Then, when I started trying my zooms, it was another story. The 16-35 f 2.8 II worked fine and was +1, +2 and seemed spot on after the adjustments. The 70-20 f2.8 (-3, +2) and 24-105 f4 (+1, +3) are disasters. The 70-200 won't focus accurately and if I take a series of photos of a test card it will FF, BF, and be spot on without any discernible pattern depending on the distance away from the card. The lens had just come back weeks ago from CPS and was given a clean bill of health. Similar story for he 24-105. Thoughts?


Feb 20, 2017 at 09:34 PM
gschlact
Offline
• • • •
Upload & Sell: Off
p.36 #7 · p.36 #7 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


Dot tune won't address inconsistency. I suggest more experimentation for those two lenses. Maybe try cleaning all the contacts and try again.

Edited on Feb 21, 2017 at 09:20 AM · View previous versions



Feb 21, 2017 at 12:43 AM
schlotz
Offline
• • • • •
Upload & Sell: On
p.36 #8 · p.36 #8 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


Are you using live view @ +10x to ensure AF during the setup? Also, does your target contain some vertical lines?


Feb 21, 2017 at 08:21 AM
armd
Offline
• • • •
Upload & Sell: On
p.36 #9 · p.36 #9 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


Yes, I've tried a variety of methods including commercial as well as printed B&W targets. All of them are in focus with live view at +10x. I'm wondering if it has something to do with my moving of the targets for the zooms based on the suggested focal length although this wouldn't explain why the 16-35 tuned accurately whereas the 24-105 and 70-200 did not? Perhaps, I should use larger targets as Canon's focus points are in fact larger than what the sensors in the viewfinder indicate. Again, these were all calibrated in good, sunny, afternoon light so that's not the problem. If the lenses were consistently inaccurate in any one direction at least I could address it, but the focus variability after tuning is astounding. I check the lenses against the DSLRkit target afterwards and if I take a series of say 5 photos (turning the image oof each time before AF again) I'll get results like this: slight ff, on, ff, bf, on. Again no discernible pattern.


Feb 23, 2017 at 09:56 PM
EGrav
Offline
• • •
Upload & Sell: Off
p.36 #10 · p.36 #10 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


armd wrote:
Does anyone still use the Dot Tune method and if so, how consistent are their results? I decided to give it a whirl yesterday as spring has come to our area and set up a series of tests with a couple of my lenses and my 5dmkIII. No problem with the primes, 50 and 85 and neither required much adjustment with that body, +1 and it seemed reproducible and reasonably accurate. Then, when I started trying my zooms, it was another story. The 16-35 f 2.8 II worked fine and was +1, +2 and seemed spot on after the adjustments.
...Show more

Dot Tune is not very consistent and reliable for Canon cameras. Too subjective dealing with confirming focus. Supposedly works great with Nikon because different way of confirming focus.



Feb 23, 2017 at 10:30 PM
 


Search in Used Dept. 

skasol
Offline
• • • •
Upload & Sell: Off
p.36 #11 · p.36 #11 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes




EGrav wrote:
Dot Tune is not very consistent and reliable for Canon cameras. Too subjective dealing with confirming focus. Supposedly works great with Nikon because different way of confirming focus.


I bought focalpro to help me with my canon



Feb 23, 2017 at 10:38 PM
schlotz
Offline
• • • • •
Upload & Sell: On
p.36 #12 · p.36 #12 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


On the other hand, I've had great success using Dot-Tune with all my Canon gear. I found the key was to pay very close attention to ANY hesitation in the AF acknowledgement (beep, or the view finder green dot). I always make a minimum of 5 attempts at AF and if any of them aren't immediate the afma setting needs to be backed off to the last known solid confirmation. JMTC


Feb 24, 2017 at 09:42 AM
gschlact
Offline
• • • •
Upload & Sell: Off
p.36 #13 · p.36 #13 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


schlotz wrote:
On the other hand, I've had great success using Dot-Tune with all my Canon gear. I found the key was to pay very close attention to ANY hesitation in the AF acknowledgement (beep, or the view finder green dot). I always make a minimum of 5 attempts at AF and if any of them aren't immediate the afma setting needs to be backed off to the last known solid confirmation. JMTC


+1
BINGO. Any AF hesitance disqualifies the MFA value.



Feb 24, 2017 at 10:45 AM
hokiejokey
Offline
• •
Upload & Sell: Off
p.36 #14 · p.36 #14 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


gschlact wrote:
+1
BINGO. Any AF hesitance disqualifies the MFA value.


It also might help to use a remote shutter release.



Feb 24, 2017 at 10:46 AM
maestrofilms
Offline
• • •
Upload & Sell: On
p.36 #15 · p.36 #15 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


I tried for 2 days to adjust my lenses with the Dot Tune technique, both manually and with Magic Lantern. I kept getting different results and couldn't make it work.

I ended up using a moiré pattern and it went quickly and accurately. I used this method with all my lenses and they are all right on the money now. I tested each one at 50X focal length, but wasn't specific about it. I just got it close. This method works really well, better than the Dot Tune method IMHO. There are just too many variables with Dot Tune. Here are a couple links showing the method, and there are quite a few other sites that describe it.


http://www.northlight-images.co.uk/camera-af-microadjustment/

If Dot Tune has been giving you trouble, try this and see if it works better for you.



Feb 24, 2017 at 12:28 PM
snapsy
Online
• • • • • •
Upload & Sell: On
p.36 #16 · p.36 #16 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


maestrofilms wrote:
I tried for 2 days to adjust my lenses with the Dot Tune technique, both manually and with Magic Lantern. I kept getting different results and couldn't make it work.

I ended up using a moiré pattern and it went quickly and accurately. I used this method with all my lenses and they are all right on the money now. I tested each one at 50X focal length, but wasn't specific about it. I just got it close. This method works really well, better than the Dot Tune method IMHO. There are just too many variables with Dot Tune. Here are
...Show more

With the automated version of DotTune in Magic Lantern, the test-to-test variability when using a locked-down focus target between invocations is +/- 1 MA unit. If however you refocus the target in between invocations then the variability will also include the user's variability of his manual focus (or CDMA if he's using LV to focus), which can be considerable when using a 2D target at 50x. This is a function of the target rather than the method, which is why I suggest using a 3D target like a lensalign, which allows the user to precisely set focus within the range of DOF that would otherwise produce a large margin of "correct" focus when using a 2D target.;

The issue with the moiré pattern method is that it can't be used at long distances. After releasing DotTune I have determined that tuning at infinity yields the best results, especially for lenses which produce distance-specific AFMA variability. Using an infinity target also reduces the margin of manual focus error during the process.



Feb 24, 2017 at 02:05 PM
maestrofilms
Offline
• • •
Upload & Sell: On
p.36 #17 · p.36 #17 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


In the same statement you said you recommend using a lensalign target, then said you recommend an object at infinity. That's confusing.

Using the moiré pattern with a laptop should cause no issues with long distances. Move the laptop into an area that you can use it. I used it on all my lenses from 16mm to 400mm.

I really appreciate what you did, and the Magic Lantern guys for implementing it. I was very excited, and read every page of this thread. I also followed instructions carefully doing it both ways....

It's just not a reliable method in my opinion.

Using the moiré pattern returned repeatable results every time with spot on accuracy. Everybody needs to find the right method for them, I guess.



Feb 24, 2017 at 02:42 PM
snapsy
Online
• • • • • •
Upload & Sell: On
p.36 #18 · p.36 #18 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


maestrofilms wrote:
In the same statement you said you recommend using a lensalign target, then said you recommend an object at infinity. That's confusing.

Using the moiré pattern with a laptop should cause no issues with long distances. Move the laptop into an area that you can use it. I used it on all my lenses from 16mm to 400mm.

I really appreciate what you did, and the Magic Lantern guys for implementing it. I was very excited, and read every page of this thread. I also followed instructions carefully doing it both ways....

It's just not a reliable method in my opinion.

Using the
...Show more

I referenced the lensalign target for those who want to use the traditional 25x - 50x focus distance for tuning and infinity for those who want best AFMA results for lenses with focus-distance specific variability. I hope that clears up the confusion.



Feb 24, 2017 at 02:54 PM
maestrofilms
Offline
• • •
Upload & Sell: On
p.36 #19 · p.36 #19 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


It does, thank you.

When I read your method of coming up with this procedure it made perfect sense. I don't know why I couldn't get good results using it. The ML automatic version made the procedure a lot easier for sure.
I'm very happy with my results now. I hope everyone can find a method that works best for them.



Feb 24, 2017 at 03:05 PM
snapsy
Online
• • • • • •
Upload & Sell: On
p.36 #20 · p.36 #20 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes


maestrofilms wrote:
It does, thank you.

When I read your method of coming up with this procedure it made perfect sense. I don't know why I couldn't get good results using it. The ML automatic version made the procedure a lot easier for sure.
I'm very happy with my results now. I hope everyone can find a method that works best for them.


In the end that's all that matters. I've always recommended people use whatever system works best for them, while also pointing out the potential limitations of each approach.



Feb 24, 2017 at 03:08 PM
1       2       3              35              37       38       end






FM Forums | Canon Forum | Join Upload & Sell

1       2       3              35              37       38       end
    
 

You are not logged in. Login or Register

Username       Or Reset password



This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.