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Author Topic: lens calibration  (Read 6370 times)

JEAraman

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lens calibration
« on: October 11, 2012, 05:19:21 PM »
Hi everyone,

my question is ,

does anyone know what Canon "does" when they take both the body and lens for calibration?

I sent in my 24-70II since I noticed that it's not as sharp as my friend's copy (we bought them one week apart). I also mentioned that it's back focusing and that I've tried using AFMA but haven't got it right and would appreciate if that can be looked at too. To my surprise I was told that AFMA "shouldn't be used" except for "special" cases. I said, that I've been doing it all the time with all my bodies and lenses. After I sent a complaint to the person in charge of after sales/ warranty, I got a call saying that the "bad focus" is because I set AFMA and that it's stored in the ROM of the Lens.. My first words "Bull $hit" I couldn't help myself. It was obvious the person talking wasn't technical. I asked, so you mean to tell me that if I set AFMA for the 24-70II on my 1DX those settings are stored on the lens.. Reply.. YES.. .. I explained why this was complete Bull$hit.!! by asking "so that means, I can't use this lens on my other camera bodies.. SILENCE..

Long story short.. I was asked to send my my 1dx which they just "reset" ALL my AFMA settings and they re-flashed the ROM on both the 1dx and 24-70II  and asked me to "retry".

I just finished testing using lensalign, (didn't feel like using focal pro). my manual testing resulted in (-4,-4).. Same as what I got with Focal Pro on the first day I got the 24-70II.

Any thoughts.. the CPS guy I spoke to wasn't very helpful.. He kept insisting that I should use the multicontroller/joystick to "SELECT the focus point"

you can imagine my frustration explaining DOF and that the little red square that's on the object tells me where I focused, and that object isn't sharp, hence SOMETHING is wrong. I asked him, do you take photos, he replied yes, I said I'm sorry but you're no photographer.. kinda mean, but I couldn't help it!!!!

Ok Rant over!!!!!!

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lens calibration
« on: October 11, 2012, 05:19:21 PM »

bycostello

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Re: lens calibration
« Reply #1 on: November 27, 2012, 09:07:57 PM »
no, that's why i send it to them to do it!

Don Haines

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Re: lens calibration
« Reply #2 on: November 27, 2012, 09:17:48 PM »
The camera (7D) allows you to store AFMA settings for up to 20 lenses.  If the value was stored on the lens, then there would be no limit as to how many lenses.

Also, it is the camera lens COMBINATION that the AFMA is set for.... If it was set on the lens, then how would it work with a different camera.... You would have to have the lens recognizing bodies....
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nitelife2

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Re: lens calibration
« Reply #3 on: November 28, 2012, 03:36:43 AM »
Hi everyone,

my question is ,

does anyone know what Canon "does" when they take both the body and lens for calibration?

Yes, I was lucky and was invited to assist in the calibration of my gear. Canon support first calibrates your camera body. They use their reference lens to calibrate the sensor plane of your body to match their lens. The calibration value is stored in the camera (You cannot see that value in the menu or anywhere else). After that they start to calibrate your lens(es) with the help of a lensalign like setup. These calibration values are stored inside the lenses. They can calibrate for the wide end and tele end and every step in between in case of zooms. Off course all AFMA values that *you* can set in the menu are reset to zero before the calibration and have to be zero afterwards.

Quote
I sent in my 24-70II since I noticed that it's not as sharp as my friend's copy (we bought them one week apart). I also mentioned that it's back focusing and that I've tried using AFMA but haven't got it right and would appreciate if that can be looked at too. To my surprise I was told that AFMA "shouldn't be used" except for "special" cases. I said, that I've been doing it all the time with all my bodies and lenses. After I sent a complaint to the person in charge of after sales/ warranty, I got a call saying that the "bad focus" is because I set AFMA and that it's stored in the ROM of the Lens..
I dont know if this was a communication/understanding error on his part as Canon really stores these calibration values in the lens. That is something the end user cant do. AFMA via the menu is different as it is a user configuration thing. Perhaps he mixed that up.

Quote
My first words "Bull $hit" I couldn't help myself. It was obvious the person talking wasn't technical. I asked, so you mean to tell me that if I set AFMA for the 24-70II on my 1DX those settings are stored on the lens.. Reply.. YES.. .. I explained why this was complete Bull$hit.!! by asking "so that means, I can't use this lens on my other camera bodies.. SILENCE..

Long story short.. I was asked to send my my 1dx which they just "reset" ALL my AFMA settings and they re-flashed the ROM on both the 1dx and 24-70II  and asked me to "retry".

I just finished testing using lensalign, (didn't feel like using focal pro). my manual testing resulted in (-4,-4).. Same as what I got with Focal Pro on the first day I got the 24-70II.
Well, Canon support is sometimes lazy and they just do nothing with your gear. They just send it back and pretend to have done something.

Quote
Any thoughts.. the CPS guy I spoke to wasn't very helpful.. He kept insisting that I should use the multicontroller/joystick to "SELECT the focus point"
Very helpful indeed...

Quote
you can imagine my frustration explaining DOF and that the little red square that's on the object tells me where I focused, and that object isn't sharp, hence SOMETHING is wrong. I asked him, do you take photos, he replied yes, I said I'm sorry but you're no photographer.. kinda mean, but I couldn't help it!!!!

Ok Rant over!!!!!!

I feel your pain. If you need help and they treat you like an idiot.

JEAraman

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Re: lens calibration
« Reply #4 on: December 13, 2012, 02:38:14 AM »
Hi Nitelife2,


I only just read your reply today.. Thanks for the descriptive reply. Your lucky to have been able to actually attend the calibration process. Canon Dubai don't actually have a "Canon service Center", it's outsourced to a 3rd party contractor.

After all my nagging, they finally sent my lens to Germany to have it calibrated. It was returned a week later with a report stating that the lens seems to be "normal/standard" with a tendency to back-focus for which they adjusted.

I still didn't have the chance to do proper testing. I wish they sent my 1dx too, however, Canon Dubai said that Canon Germany said NOT to send the body, only the lens.

I wonder if I can just contact Canon UK or some country with a proper Canon Service center and ship my equipment for proper calibration...

Hi everyone,

my question is ,

does anyone know what Canon "does" when they take both the body and lens for calibration?

Yes, I was lucky and was invited to assist in the calibration of my gear. Canon support first calibrates your camera body. They use their reference lens to calibrate the sensor plane of your body to match their lens. The calibration value is stored in the camera (You cannot see that value in the menu or anywhere else). After that they start to calibrate your lens(es) with the help of a lensalign like setup. These calibration values are stored inside the lenses. They can calibrate for the wide end and tele end and every step in between in case of zooms. Off course all AFMA values that *you* can set in the menu are reset to zero before the calibration and have to be zero afterwards.

Quote
I sent in my 24-70II since I noticed that it's not as sharp as my friend's copy (we bought them one week apart). I also mentioned that it's back focusing and that I've tried using AFMA but haven't got it right and would appreciate if that can be looked at too. To my surprise I was told that AFMA "shouldn't be used" except for "special" cases. I said, that I've been doing it all the time with all my bodies and lenses. After I sent a complaint to the person in charge of after sales/ warranty, I got a call saying that the "bad focus" is because I set AFMA and that it's stored in the ROM of the Lens..
I dont know if this was a communication/understanding error on his part as Canon really stores these calibration values in the lens. That is something the end user cant do. AFMA via the menu is different as it is a user configuration thing. Perhaps he mixed that up.

Quote
My first words "Bull $hit" I couldn't help myself. It was obvious the person talking wasn't technical. I asked, so you mean to tell me that if I set AFMA for the 24-70II on my 1DX those settings are stored on the lens.. Reply.. YES.. .. I explained why this was complete Bull$hit.!! by asking "so that means, I can't use this lens on my other camera bodies.. SILENCE..

Long story short.. I was asked to send my my 1dx which they just "reset" ALL my AFMA settings and they re-flashed the ROM on both the 1dx and 24-70II  and asked me to "retry".

I just finished testing using lensalign, (didn't feel like using focal pro). my manual testing resulted in (-4,-4).. Same as what I got with Focal Pro on the first day I got the 24-70II.
Well, Canon support is sometimes lazy and they just do nothing with your gear. They just send it back and pretend to have done something.

Quote
Any thoughts.. the CPS guy I spoke to wasn't very helpful.. He kept insisting that I should use the multicontroller/joystick to "SELECT the focus point"
Very helpful indeed...

Quote
you can imagine my frustration explaining DOF and that the little red square that's on the object tells me where I focused, and that object isn't sharp, hence SOMETHING is wrong. I asked him, do you take photos, he replied yes, I said I'm sorry but you're no photographer.. kinda mean, but I couldn't help it!!!!

Ok Rant over!!!!!!

I feel your pain. If you need help and they treat you like an idiot.

nitelife2

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Re: lens calibration
« Reply #5 on: December 17, 2012, 05:53:52 PM »
If you have a 1Dx I wouldnt let Canon do the calibration. Your body allows AFMA for the wide and tele end. All values in between these ends are interpolated.

To find the best AFMA values get a license of focal pro. It is an excellent piece of software from reikan/UK. That way you can be sure that you really have the best calibration possible.

JEAraman

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Re: lens calibration
« Reply #6 on: December 18, 2012, 03:10:10 AM »
Thanks for the info nitelife2,

in fact, I do have focal pro but I wasn't getting a consisten result. That's what prompted me to open the case with Canon in the first place. I need to reprint the targets and do the tests soon.

Cheers

If you have a 1Dx I wouldnt let Canon do the calibration. Your body allows AFMA for the wide and tele end. All values in between these ends are interpolated.

To find the best AFMA values get a license of focal pro. It is an excellent piece of software from reikan/UK. That way you can be sure that you really have the best calibration possible.

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Re: lens calibration
« Reply #6 on: December 18, 2012, 03:10:10 AM »

neuroanatomist

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Re: lens calibration
« Reply #7 on: December 18, 2012, 09:40:11 AM »
in fact, I do have focal pro but I wasn't getting a consisten result.

Usually, there are two reasons for inconsistent results with FoCal - an unstable setup and/or not enough light.  I started running tests on the main floor of my house, hardwood flooring, and even with a stable tripod me or my kids walking by perturbed the results.  I moved the setup to the basement, concrete slab floor, no more problems.  I use LOTS of light - 3 150 W-equivalent tungsten lights at a distance of 12-14" from the target.  FoCal reports the EV reading for the test, mine are in the 11-12 range.  If you're below 10 EV, that can cause problems.
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Dylan777

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Re: lens calibration
« Reply #8 on: December 18, 2012, 10:19:50 AM »
in fact, I do have focal pro but I wasn't getting a consisten result.

Usually, there are two reasons for inconsistent results with FoCal - an unstable setup and/or not enough light.  I started running tests on the main floor of my house, hardwood flooring, and even with a stable tripod me or my kids walking by perturbed the results.  I moved the setup to the basement, concrete slab floor, no more problems.  I use LOTS of light - 3 150 W-equivalent tungsten lights at a distance of 12-14" from the target.  FoCal reports the EV reading for the test, mine are in the 11-12 range.  If you're below 10 EV, that can cause problems.

Since I don't have any special lighting as Neuro does. I setup my target outdoor, mid afternoon for better lighting.

1. Put some weights on that tripod to prevent from shifting
2. Make sure the ball head on your tripod is completely tight
2. Be extra carefull when you change the AFMA values during test. In my case, 5D III is not fully auto yet

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neuroanatomist

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Re: lens calibration
« Reply #9 on: December 18, 2012, 10:35:24 AM »
Since I don't have any special lighting as Neuro does. I setup my target outdoor, mid afternoon for better lighting.

I wouldn't call gooseneck desk lamps from Staples with projector bulbs in them particularly 'special'...   :P

With an outdoor setup, make sure there are no clouds.  Also, no or minimal wind.
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Dylan777

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Re: lens calibration
« Reply #10 on: December 18, 2012, 10:59:01 AM »
Since I don't have any special lighting as Neuro does. I setup my target outdoor, mid afternoon for better lighting.

I wouldn't call gooseneck desk lamps from Staples with projector bulbs in them particularly 'special'...   :P

With an outdoor setup, make sure there are no clouds.  Also, no or minimal wind.

I spent all $$$ on 5D III + 24-70 II, and 50L.....nothing left for gooseneck desk lamps :P

I'll keep that tip in mind next time...thanks Neuro
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Re: lens calibration
« Reply #11 on: December 18, 2012, 12:05:39 PM »
This is the AF adjustment from 2009 and 5dmk2.
Today, they have a bit more modern setups but the principle is the same

First  Canon will adjust the cameras AF  with a fixed  f-2,8 reference lens, the lens can not been focus  and are  an custom made lens for measurement of  the AF points in the camera. When the house is adjust and set at 0 (zero) ​​ they start to adjust the lenses.
A zoom lens can be adjustusted up to 8 different calibrations points through the zoom range and this calibration takes a long time and is the most accurate for a zoom, the data is transferred to the lens CPU,   usually  Canon makes AF adjustments  in the end positions such as 24mm and 105mm in a 24-105/4  ,  70 and 200mm etc.
The adjustment is always done in the distance of 50 x focal length, 50mm = 2,5 m ,  100mm lens = 5m distance to the test board.
Longer lenses 400mm / 2.8  are adjusted with help of mirrors, since the distance is 20m and  will be follow up with test shoots outside.

http://translate.googleusercontent.com/translate_c?act=url&depth=1&hl=sv&ie=UTF8&prev=_t&rurl=translate.google.com&sl=sv&tl=en&twu=1&u=http://www.fotosidan.se/forum/showthread.php%3Ft%3D104797&usg=ALkJrhjlkjz6Ei9NoH700it_mLrtR94R7g

Mikael, thanks for the detailed info.  I was generally aware of how they did it, but more details are good to have.   :)

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Re: lens calibration
« Reply #12 on: December 18, 2012, 01:56:38 PM »
Wow.  Interesting read folks.  I'm getting pretty close to pulling the trigger on FoCal.

Can't wait to get those gooseneck lamps.  Now I know neuro's secret!!  I didn't know Staples was an authorized Canon dealer.  What is the Canon SKU for those fancy lamps neuro?   ;D

Also, what's the deal about 5DIII not being fully auto?  Are we waiting for FoCal to update something or what?  Please explain.  Thanks.
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Re: lens calibration
« Reply #12 on: December 18, 2012, 01:56:38 PM »

neuroanatomist

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Re: lens calibration
« Reply #13 on: December 18, 2012, 01:59:43 PM »
Also, what's the deal about 5DIII not being fully auto?  Are we waiting for FoCal to update something or what?  Please explain.  Thanks.

Seems the ability to set AFMA remotely was removed (by Canon) from the SDK.  So until Canon updates the SDK to have that ability (if ever, maybe they looked at the modest additional code needed to support setting separate W and T values, and decided it wasn't worth the effort?), it's semi-auto for FoCal with the 5DIII and 1D X (not sure about 6D, but probably it's the same since it has the same AFMA features).
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Re: lens calibration
« Reply #14 on: December 18, 2012, 02:10:16 PM »
Thanks for the info neuro.  That's sort of what I suspected/feared.  I wish Canon would step up and provide a full featured software management solution for all DSLRs and other cameras.  Like the ability to do auto AFMA, backup of all camera settings (like profiles) to a PC, etc.  I realize they have some of this in a limited or manual fashion but there is so much potential if they would just expand on it.  Coming from a computer and IT background, I guess I just see a lot of things "missing" that shouldn't be with regard to the technology involved.
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Re: lens calibration
« Reply #14 on: December 18, 2012, 02:10:16 PM »