Approve the Cookies
This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and our Privacy Policy.
OK
Index  •   • New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Guest
New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Register to forums    Log in

 
FORUMS Canon Cameras, Lenses & Accessories Canon EF and EF-S Lenses 
Thread started 19 Mar 2013 (Tuesday) 17:58
Search threadPrev/next
sponsored links
(this ad will go away when you log in as a registered member)

What is your lens micro adjust technique?

 
pulsar123
Goldmember
2,143 posts
Gallery: 67 photos
Best ofs: 1
Likes: 481
Joined Apr 2010
Location: Canada
     
Jun 15, 2013 19:36 |  #46

No, the correct answer is "to take median". You are confused with a totally unrelated fact: the 1/3 anf 2/3 DoF rule is about physical distance, but MA is not measured in feet or meters; it is rather measured in DoF units (8 MA units per one DoF step, according to info I saw on the web). Then median is exactly what you want - to be equidistant from the bad MA edges, in DoF units.


6D, Tamron 24-70 f2.8 VC, 135L, 70-200 f4L, Laowa 15mm 1:1 macro, 50mm f1.8 STM, Samyang 8mm fisheye, home studio

  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)
Refill
Member
Avatar
177 posts
Joined Jan 2013
Location: Euro
     
Jun 15, 2013 20:28 |  #47

pulsar123 wrote in post #16034537 (external link)
No, the correct answer is "to take median". You are confused with a totally unrelated fact: the 1/3 anf 2/3 DoF rule is about physical distance, but MA is not measured in feet or meters; it is rather measured in DoF units (8 MA units per one DoF step, according to info I saw on the web). Then median is exactly what you want - to be equidistant from the bad MA edges, in DoF units.

You are probably right, but I doubt this is totally unrelated, as for every half DOF unit the physical distance double, the relation between DOF steps and distance is quite closely related.




  
  LOG IN TO REPLY
hollis_f
Cream of the Crop
Avatar
10,649 posts
Gallery: 1 photo
Likes: 85
Joined Jul 2007
Location: Sussex, UK
     
Jun 16, 2013 07:07 |  #48

Refill wrote in post #16034396 (external link)
But with the DOF -1/3 +2/3 rule

What is the rule of which you speak?

Has it got something to do with the oft-repeated fallacy about Depth of Field being 1/3 in front of the subject and 2/3 behind the subject? If so, you do realise that this 'rule' applies at just one single focal length?


Frank Hollis - Retired mass spectroscopist
Give a man a fish and he'll eat for a day. Teach a man to fish and he'll complain about the withdrawal of his free fish entitlement.
Gear Website (external link)

  
  LOG IN TO REPLY
Refill
Member
Avatar
177 posts
Joined Jan 2013
Location: Euro
     
Jun 16, 2013 13:10 as a reply to  @ hollis_f's post |  #49

Anyway, I have been trying this Dot Tune method today with my 400mm f/5.6.

A real disaster! At f/5.6 I got -8 and +20 MFA as limits. I was curious and tried at f/11, results -6 +16. F/32? again -8 +20. There is a high variability on the limits.

I certainly won't take the median here, because

1.this lens was fine at 0 MFA
2. the MFA does NOT modify the way this lens focuses!

Yes, you read it right: no visible effect on this lens focus, whatever MFA setting I chose! What is happening here? Very strange. I had to tune one of my Sigma lens before, and I could see the difference, for sure! But here this method and the 7D MFA settings don't seem to change anything! I wonder what went wrong?

I had only the 400 and some manual focus lens, but I will try this Dot Tune method again with the Sigma, when I have some time to go out.




  
  LOG IN TO REPLY
Eddie
xpfloyd lookalike
Avatar
13,289 posts
Gallery: 620 photos
Best ofs: 7
Likes: 8521
Joined Feb 2011
Location: Glasgow, Scotland
     
Jul 20, 2013 04:20 |  #50

Interesting read, will give dot tune a try today


α7R III | Mavic 2 Pro | Osmo Pocket | GoPro Hero 7 Black

  
  LOG IN TO REPLY
eddieb1
Senior Member
Avatar
867 posts
Likes: 175
Joined Apr 2013
Location: Oregon
     
Jul 22, 2013 09:42 |  #51

mitchrapp wrote in post #15738812 (external link)
As pulsar123 stated, you have to use the nightlies.

Where to find the nightlies? I've looked all over their site, I find the nightlies for the 60D, but nothing for the 7D.




  
  LOG IN TO REPLY
msowsun
"approx 8mm"
Avatar
9,266 posts
Gallery: 18 photos
Best ofs: 1
Likes: 359
Joined Jul 2007
Location: Oakville Ont. Canada
     
Jul 22, 2013 10:54 |  #52

pulsar123 wrote in post #15734220 (external link)
And dot-tune is now part of Magic Lantern - so the whole calibration is fully automatic (it takes 30 seconds to calibrate a lens). The word of caution - with any method you use, good light and good target make all the difference.

I used Magic Lantern "Nightly Builds" to get Dot Tune AFMA on my 5D Mk II. It works really well and is totally automatic. The Nightly Builds are not readily usable for the 7D or 5D Mk III and you have to go through a more complicated process to get them to work. I think it involves creating a "bootable" memory card and then writing some of your own code.

Before I start looking into how to get Dot Tune AFMA working on a 5D Mk III, does anyone know if it is even possible?


Mike Sowsun / SL1 / 80D / EF-S 24mm STM / EF-S 10-18mm STM / EF-S 18-55mm STM / EF-S 15-85mm USM / EF-S 55-250mm STM / 5D3 / Samyang 14mm 2.8 / EF 40mm 2.8 STM / EF 50mm 1.8 STM / EF 100mm 2.0 USM / EF 100mm 2.8 USM Macro / EF 24-105mm IS / EF 70-200mm 2.8L IS Mk II / EF 100-400 II / EF 1.4x II
Full Current and Previously Owned Gear List over 40 years Flickr Photostream (external link)

  
  LOG IN TO REPLY
pulsar123
Goldmember
2,143 posts
Gallery: 67 photos
Best ofs: 1
Likes: 481
Joined Apr 2010
Location: Canada
     
Jul 22, 2013 16:01 |  #53

Unless I am reading it wrong, dot-tune was apparently added to 5D3 Unified build in March:

https://bitbucket.org …atform/5D3.113?​at=unified (external link)

Also, ChangeLog on the Nightly pages does mention 5D3, so I'm pretty sure the dot-tune should be there for 5D3:

http://www.magiclanter​n.fm/forum/index.php?t​opic=3072.0 (external link)

7D seems to be there as well.


6D, Tamron 24-70 f2.8 VC, 135L, 70-200 f4L, Laowa 15mm 1:1 macro, 50mm f1.8 STM, Samyang 8mm fisheye, home studio

  
  LOG IN TO REPLY
lobby
Member
119 posts
Likes: 1
Joined Jun 2013
Location: Chicago
     
Jul 22, 2013 16:02 |  #54

When taking focus distance into account, do you have to compensate for crop factor? For example, they recommend 50x the focal length you're testing. So if I want to calibrate a 28mm lens, do I have to do 28 x 1.6 x 50?


6D + 28-70mm f/2.8 L + Sigma 400mm f/5.6 HSM + 550EX

  
  LOG IN TO REPLY
Andrew_WOT
Goldmember
1,418 posts
Joined Mar 2010
Location: CA
     
Jul 22, 2013 18:24 as a reply to  @ lobby's post |  #55

Lensalign recommendation is 25xFL instead of 50x
https://mtd.tenderapp.​com …tool-when-using-lensalign (external link)
Kind of makes sense as it's easier to dial AF with shallower DOF, 50x is what recommended by Canon, kind of hard to find hallway that big to test tele lens. :)

They also have Distance tool to calculate distance for different FL and crop factor
http://www.whibalhost.​com/lensalign/ldt/inde​x.html (external link)




  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)

9,533 views & 0 likes for this thread
What is your lens micro adjust technique?
FORUMS Canon Cameras, Lenses & Accessories Canon EF and EF-S Lenses 
AAA
x 1600
y 1600

Jump to forum...   •  Rules   •  Index   •  New posts   •  RTAT   •  'Best of'   •  Gallery   •  Gear   •  Reviews   •  Member list   •  Polls   •  Image rules   •  Search   •  Password reset

Not a member yet?
Register to forums
Registered members may log in to forums and access all the features: full search, image upload, follow forums, own gear list and ratings, likes, more forums, private messaging, thread follow, notifications, own gallery, all settings, view hosted photos, own reviews, see more and do more... and all is free. Don't be a stranger - register now and start posting!


COOKIES DISCLAIMER: This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and to our privacy policy.
Privacy policy and cookie usage info.


POWERED BY AMASS forum software 2.1forum software
version 2.1 /
code and design
by Pekka Saarinen ©
for photography-on-the.net

Latest registered member is All-Media-Services
967 guests, 360 members online
Simultaneous users record so far is 15144, that happened on Nov 22, 2018

Photography-on-the.net Digital Photography Forums is the website for photographers and all who love great photos, camera and post processing techniques, gear talk, discussion and sharing. Professionals, hobbyists, newbies and those who don't even own a camera -- all are welcome regardless of skill, favourite brand, gear, gender or age. Registering and usage is free.