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 05 Aug 2014 (Tuesday) 11:14
Search threadPrev/next
sponsored links
(this ad will go away when you log in as a registered member)

Looking for help calibrating Sigma 18-35 with dock.

 
Aressem
Goldmember
Avatar
4,364 posts
Gallery: 39 photos
Best ofs: 1
Likes: 511
Joined Dec 2009
Location: Vancouver, BC
     
Aug 05, 2014 11:14 |  #1

I purchased my neighbor's 6 month old, barely used 18-35mm f/1.8 for $600 CDN. Seemed like too good of a deal to pass on. It's front focusing terribly on my 7D so I need to calibrate it. I've used the "Dot Tune" method in the past and am wondering if this will yield me the best results. Who has calibrated their 18-35 using the dock? Just hoping for advice. Be as detailed as possible. Thanks!


Ryan Mackay WEBSITE (external link) | FACEBOOK (external link) | GEAR LIST | Buy & Sell Feedback: 1, 2, 3, 4, 5

  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)
FEChariot
Goldmember
Avatar
4,423 posts
Gallery: 13 photos
Likes: 345
Joined Sep 2011
     
Aug 05, 2014 14:48 |  #2

I'm no help with the dock, but I would calibrate it using the AFMA on the 7D first. If you use the dock, you have to keep mounting it on the camera and then the dock and so on until its right. If you see a situation where you are getting front focusing up close and back focusing on distant objects (or vice versa), then start using the dock to more or less program in a slope of the focus line based on subject distance to correct for that. Canon AFMA can only adjust the zero point and not the slope of the line so that is where the Sigma dock will help.


Canon 7D/350D, Σ17-50/2.8 OS, 18-55IS, 24-105/4 L IS, Σ30/1.4 EX, 50/1.8, C50/1.4, 55-250IS, 60/2.8, 70-200/4 L IS, 85/1.8, 100/2.8 IS L, 135/2 L 580EX II, 430EX II * 2, 270EX II.

  
  LOG IN TO REPLY
Aressem
THREAD ­ STARTER
Goldmember
Avatar
4,364 posts
Gallery: 39 photos
Best ofs: 1
Likes: 511
Joined Dec 2009
Location: Vancouver, BC
     
Aug 05, 2014 18:13 |  #3

FEChariot wrote in post #17078073 (external link)
I'm no help with the dock, but I would calibrate it using the AFMA on the 7D first. If you use the dock, you have to keep mounting it on the camera and then the dock and so on until its right. If you see a situation where you are getting front focusing up close and back focusing on distant objects (or vice versa), then start using the dock to more or less program in a slope of the focus line based on subject distance to correct for that. Canon AFMA can only adjust the zero point and not the slope of the line so that is where the Sigma dock will help.

Unfortunately this doesn't help me much :p the dock allows 16 MA variables.


Ryan Mackay WEBSITE (external link) | FACEBOOK (external link) | GEAR LIST | Buy & Sell Feedback: 1, 2, 3, 4, 5

  
  LOG IN TO REPLY
DreDaze
happy with myself for not saying anything stupid
Avatar
18,192 posts
Gallery: 45 photos
Likes: 2614
Joined Mar 2006
Location: S.F. Bay Area
     
Aug 05, 2014 18:57 |  #4

i didn't have to calibrate my 120-300OS, but i could see it being a bit of a pain if you had to...i think fechariot's suggestion of seeing if it works with just the Micro focus adjust of your 7D could be a good one...and if the lens is consistently focusing incorrectly it may be all you need...if however the focusing is different for varying subject locations, you'll have no choice but to take the time to do it on the dock


Andre or Dre
gear list
Instagram (external link)
flickr (external link)

  
  LOG IN TO REPLY
gremlin75
Goldmember
Avatar
2,727 posts
Gallery: 4 photos
Likes: 216
Joined Feb 2011
Location: Detroit, MI
     
Aug 05, 2014 19:43 |  #5

I calibrated my 18-35 with the dock manually.

Basically I just set up the target at each distant shown in the calibration software. I'd Take a shot, switch to live view, zoom in on live view and manually focus the lens to get proper focus (to check for front or back focus). I'd do this several times to make sure it was infact front or back focusing.

After that I'd take the lens off the camera (that I had on my tripod), hook it to my computer, then just take an educated guess at how much adjustment was needed. If I had to correct focus by a lot then I made a larger adjustment then if I just had to tweak the focus a little. Disconnet the lens from the dock, Re-mount the lens, and start the process over again until the focus was right on.

Once the focus was right I'd move onto the next focal length for that distance. When I fixed each focal length at a certain distance I'd move onto the next of focus distance.

Not hard just time consuming. I tried a couple different ways first but the method above is what worked best for me. With that method it took me about an hour to go through all 16 adjustment values. A put the screen shot of my final adjustments in the 18-35 sample thread.......I would highly suggest saving a screen shot of the final adjustment screen just in case the lens reset the adjustment after a firmware update or anything.

Oh and nice deal you got on the lens too!




  
  LOG IN TO REPLY
pkim1230
Senior Member
Avatar
746 posts
Joined Apr 2011
Location: Providence, RI
     
Aug 05, 2014 20:32 |  #6

I rented this lens and it was front focusing really badly too.
Made a post about it in the lens archive.
I've never had a problem with 10-20, 30, 17-70 sigmas, except the 18-35 was so bad.
I think it was because it was a rental. And the rental shop didn't even have the dock available for adjusting. I had to just take it or leave it.



Gear | 6D, 550D, 1000D IR Modified, Samyang 24mm f/1.4, Rokinon 14mm f/2.8, Canon 40mm f/2.8, Tamron 70-300mm VC f/4-5.6, iOptron SkyTracker

  
  LOG IN TO REPLY
Aressem
THREAD ­ STARTER
Goldmember
Avatar
4,364 posts
Gallery: 39 photos
Best ofs: 1
Likes: 511
Joined Dec 2009
Location: Vancouver, BC
     
Aug 05, 2014 22:19 |  #7

Thanks everyone. I think I'm going to go with my gut and use the Dot Tune method. It astounds me how little information there is considering how many people and reviewers rave about the Dock. I will make a video to share my experience once done. If anyone else wants to chime in, it'd be appreciated. :)


Ryan Mackay WEBSITE (external link) | FACEBOOK (external link) | GEAR LIST | Buy & Sell Feedback: 1, 2, 3, 4, 5

  
  LOG IN TO REPLY
FEChariot
Goldmember
Avatar
4,423 posts
Gallery: 13 photos
Likes: 345
Joined Sep 2011
     
Aug 06, 2014 01:44 |  #8

Aressem wrote in post #17078486 (external link)
Unfortunately this doesn't help me much :p the dock allows 16 MA variables.

Yes you have 4 settings for subject distance times 4 focal lengths. Like I said, use your 7D AFMA with a close subject near MFD and test. Dot tune works but I personally like to take a shot using live view contrast detect and compare to Viewfinder phase detect results. If it is softer via phase detect, then compare the best of about 5 shots at -20,-15,-10 up to +20 and pick the sharpest MA. Then fine tune + or - 5 by ones. Then test on a subject about 50 times focal length and see if the same AFMA value is the sharpest.

If the numbers are not the same, then you have a slope issue that could not be fixed without sending the lens to be calibrated in the shop before the new dock. Now you can program the slope back in. So say at 18mm you find -10 at MFD and then moving out its -6, -2, +2. Now the slop of +4 is in. Remember this is just like alegebra calculating the slope of a line y = mx +b. The AFMA in Canon cameras can only adjust the zero point. If your slope is not off, I wouldn't bother with using the dock.

You then repeat for 24mm, 28mm and 35mm.


Canon 7D/350D, Σ17-50/2.8 OS, 18-55IS, 24-105/4 L IS, Σ30/1.4 EX, 50/1.8, C50/1.4, 55-250IS, 60/2.8, 70-200/4 L IS, 85/1.8, 100/2.8 IS L, 135/2 L 580EX II, 430EX II * 2, 270EX II.

  
  LOG IN TO REPLY
sploo
premature adulation
2,414 posts
Gallery: 1 photo
Likes: 464
Joined Nov 2011
Location: West Yorkshire, UK
     
Aug 06, 2014 03:36 |  #9

FEChariot wrote in post #17079287 (external link)
If it is softer via phase detect

A note to save you a "doh!" moment; make sure you've enabled mirror lockup when taking the viewfinder/phase detect shots; the slap of the mirror (which is of course already up in Liveview) can make the viewfinder shots subtly softer, even if you've nailed focus. I spent a good few minutes scratching my head once over that, before realising my mistake.

Edit: by "you" I of course mean anyone trying this process that hasn't done it before


Camera, some lenses, too little time, too little talent

  
  LOG IN TO REPLY
mwsilver
Goldmember
3,899 posts
Gallery: 51 photos
Likes: 491
Joined Oct 2011
Location: Central New Jersey
     
Aug 07, 2014 00:16 |  #10

Aressem wrote in post #17078992 (external link)
Thanks everyone. I think I'm going to go with my gut and use the Dot Tune method. It astounds me how little information there is considering how many people and reviewers rave about the Dock. I will make a video to share my experience once done. If anyone else wants to chime in, it'd be appreciated. :)

The software has minimal functionality and does nothing to assist you in the calibration process. You are basically on your own. Luckily my copy needed a minimum of adjustment on my 60D. With 16 different setting to adjust for its a very very time consuming process. You may also find that while at say f/4 the AF is spot on almost of the time, at f/1.8 the AF is less consistent, sometimes front or back focusing just a bit.. The dock won't do much to correct that since the corrections are based on focal length and distance, not the aperture used. What aperture were you using to test the lens? If you were wide open, I would stop down to at least f/4 and see how it performs at that aperture.


Mark
Canon 7D2, 60D, T3i, T2i, Sigma 18-35 f/1.8, 30 f/1.4. Canon EF 70-200 L f/4 IS, EF 35 f/2 IS, EFs 10-18 STM, EFs 15-85, EFs 18-200, EF 50 f/1.8 STM, Tamron 18-270 PZD, B+W MRC CPL, Canon 320EX, Vanguard Alta Pro 254CT & SBH 250 head. RODE Stereo Videomic Pro, DXO PhotoLab Elite, ON1

  
  LOG IN TO REPLY
Aressem
THREAD ­ STARTER
Goldmember
Avatar
4,364 posts
Gallery: 39 photos
Best ofs: 1
Likes: 511
Joined Dec 2009
Location: Vancouver, BC
     
Aug 07, 2014 08:09 |  #11

mwsilver wrote in post #17081306 (external link)
The software has minimal functionality and does nothing to assist you in the calibration process. You are basically on your own. Luckily my copy needed a minimum of adjustment on my 60D. With 16 different setting to adjust for its a very very time consuming process. You may also find that while at say f/4 the AF is spot on almost of the time, at f/1.8 the AF is less consistent, sometimes front or back focusing just a bit.. The dock won't do much to correct that since the corrections are based on focal length and distance, not the aperture used. What aperture were you using to test the lens? If you were wide open, I would stop down to at least f/4 and see how it performs at that aperture.

Considering I plan on using it a lot wide open, I will likely calibrate it at f/1.8.


Ryan Mackay WEBSITE (external link) | FACEBOOK (external link) | GEAR LIST | Buy & Sell Feedback: 1, 2, 3, 4, 5

  
  LOG IN TO REPLY
mwsilver
Goldmember
3,899 posts
Gallery: 51 photos
Likes: 491
Joined Oct 2011
Location: Central New Jersey
     
Aug 07, 2014 09:37 |  #12

Aressem wrote in post #17081711 (external link)
Considering I plan on using it a lot wide open, I will likely calibrate it at f/1.8.

I tried that. I hope you have better luck. At f/4 AF is dead on 95% of the time. At f/1.8. that percentage drops down to 65 to 70% depending on lighting, the size of the subject target, and the contrast of the subject. Larger, high contrast subjects do much better. When shooting wide open I try to focus on a point on the target when there is a sharp contrasting edge, if I can. The hit rate goes up significantly. When stopped down, the hit rate is similar to my slower Canon lenses. For what it worth, the AF hit rate wide open with my Canon 50mm f/1.8 isn't much better. When I have lighting issues that impact the Sigma's AF, there is always live view, which is not affected, and of course manual focus.


Mark
Canon 7D2, 60D, T3i, T2i, Sigma 18-35 f/1.8, 30 f/1.4. Canon EF 70-200 L f/4 IS, EF 35 f/2 IS, EFs 10-18 STM, EFs 15-85, EFs 18-200, EF 50 f/1.8 STM, Tamron 18-270 PZD, B+W MRC CPL, Canon 320EX, Vanguard Alta Pro 254CT & SBH 250 head. RODE Stereo Videomic Pro, DXO PhotoLab Elite, ON1

  
  LOG IN TO REPLY
Nivekolleh
Hatchling
5 posts
Joined Dec 2012
     
Aug 07, 2014 23:15 |  #13

Sorry to piggyback off your thread but I just tried calibrating mine and here are the results I got

IMAGE: http://i.imgur.com/ON7XBvd.png

it seems like too much in some spots, at 18mm, i'm still getting shaky results sometimes, so i let it go for the day and will go back to it tomorrow.

Does this look right to anyone?

Also how did people adjust theirs at near infinity, I have mine set at 80" but it's hard to tell if it's back or front focusing at all



  
  LOG IN TO REPLY
gremlin75
Goldmember
Avatar
2,727 posts
Gallery: 4 photos
Likes: 216
Joined Feb 2011
Location: Detroit, MI
     
Aug 11, 2014 20:42 |  #14

Nivekolleh wrote in post #17083308 (external link)
Also how did people adjust theirs at near infinity, I have mine set at 80" but it's hard to tell if it's back or front focusing at all

As I posted earlier:

gremlin75 wrote in post #17078670 (external link)
I calibrated my 18-35 with the dock manually.

Basically I just set up the target at each distant shown in the calibration software. I'd Take a shot, switch to live view, zoom in on live view and manually focus the lens to get proper focus (to check for front or back focus). I'd do this several times to make sure it was infact front or back focusing.

If your camera doesn't have live view then you'll have to get a target that will show if there is front of back focus. This one (external link) worked ok but I found my live view method worked better for me. I have never used "dot tune"

Your 18mm settings seem all over the place to me. I'd go back and re-test them.




  
  LOG IN TO REPLY
mwsilver
Goldmember
3,899 posts
Gallery: 51 photos
Likes: 491
Joined Oct 2011
Location: Central New Jersey
     
Aug 11, 2014 21:45 |  #15

Nivekolleh wrote in post #17083308 (external link)
Sorry to piggyback off your thread but I just tried calibrating mine and here are the results I got

QUOTED IMAGE

it seems like too much in some spots, at 18mm, i'm still getting shaky results sometimes, so i let it go for the day and will go back to it tomorrow.

Does this look right to anyone?

Also how did people adjust theirs at near infinity, I have mine set at 80" but it's hard to tell if it's back or front focusing at all

It will vary depending on the body its mounted on and even the specific copy of the lens.


Mark
Canon 7D2, 60D, T3i, T2i, Sigma 18-35 f/1.8, 30 f/1.4. Canon EF 70-200 L f/4 IS, EF 35 f/2 IS, EFs 10-18 STM, EFs 15-85, EFs 18-200, EF 50 f/1.8 STM, Tamron 18-270 PZD, B+W MRC CPL, Canon 320EX, Vanguard Alta Pro 254CT & SBH 250 head. RODE Stereo Videomic Pro, DXO PhotoLab Elite, ON1

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

9,467 views & 1 like for this thread
Looking for help calibrating Sigma 18-35 with dock.
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 Sacramento Taxi
773 guests, 293 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.