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Archive 2012 · Canon 7D & lens micro adjustment
  
 
elyimages
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p.1 #1 · Canon 7D & lens micro adjustment


Hello all, I am new here. I often enjoy reading all of the great information on this site. So now that I have a problem I could not wait to post. Sorry about the length of the post, but any help would be greatly appreciated.

I took my Canon 7D and four of my “L” lenses to have them micro adjusted to the camera body.
I took them to a Canon Authorized Service Center. One of the only 10 Canon Authorized Service Center in the United States trained to service the IS and L series lens.

I picked up my lenses, and when I got home I checked the settings to see how much adjustment was need for each lens. When I put on my 17-40 f/4 L it was not registered to the camera and no micro adjustment was done.

So I sent them an email right away and this is the reply I got.
“Sorry, the tech had a note with it that must have not gotten on the paperwork. This lens has a focus shift problem, in other works one end of the zoom is front focusing and the other end of the zoom is back focusing. On most of the new lens model you can electronically adjust for this via computer adjustment, each end of the zoom and middle having their own adjustment, on this model there is just one over all adjustment. The only way to correct this is be taking the lens apart and doing an optical alignment, the cost of doing this on the lens is $179.00 includes clean, lube and adjust.”

My reply to them
“How can it be determined that a lens has such extreme focus shift problem if the lens was never registered to the camera to begin the process of micro adjusting?”

And there last reply to me
“Before a zoom lens can be micro adjusted we must first check the lens to see if the wide and tele focus match as the camera only has one micro setting per lens, if the tele wide to not match it can't be micro adjusted as one end would still be off. Therefore the camera would not show that is was micro adjusted. If the tele and wide match, then the lens is tested on the camera to be micro adjusted to determine the amount of adjusted needed and them input into the camera. The pre testing of your lens is not done on your body but with a master body and test equipment.”

The lens is brand new and only a month old.
Is this the way lenses are micro calibrated to a body when you take them to a Canon Authorized Service Center or am I suffering from extreme consumer paranoia?



Apr 03, 2012 at 11:46 AM
uz2work
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p.1 #2 · Canon 7D & lens micro adjustment


The micro adjust feature that Canon has built into cameras for the last 5 years or so and that is available to the camera user is completely separate from the means of calibration used by Canon service techs when you send a body and lens into Canon to be calibrated. Thus, if Canon service does calibration, there is no "registration" of the lens via the camera menu.

Also, it is not unusual, with a zoom lens, for focus accuracy to be different at one end of the zoom range compared to the other end of the zoom range. If that difference is beyond the range of factory specs and if the lens is still under warranty, I would think that Canon should be correcting any problems at no cost to you; however, if the difference is within factory spec, I would not expect them to do so.

Otherwise, I'm a bit confused by some of the exchange between you and Canon service.

Les



Apr 03, 2012 at 12:07 PM
JohnBrose
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p.1 #3 · Canon 7D & lens micro adjustment


Maybe they were not aware that the lens is still under warranty?


Apr 03, 2012 at 12:14 PM
elyimages
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p.1 #4 · Canon 7D & lens micro adjustment


Les,

I am not sure they used the method you are referring to.
My 70-200, 24-70 & 24-105 all were registered and showed micro adjustment in the camera. My 17-40 was not registered to the camera. I was not told there was a problem with any of my lenses when I was at the service center, and they just finished up the work.
Only after I sent a email asking about it I found out there was a problem.
And I understand that even new lenses will have a problem and need to be sent in.
Just not sure why the other lenes where done in camera and this one was not.

John-yes I am sure they did not know the lens was under warranty.



Apr 03, 2012 at 12:45 PM
Wahoowa
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p.1 #5 · Canon 7D & lens micro adjustment


It should be free of charge if it's still under warranty.


Apr 03, 2012 at 01:20 PM
 

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uz2work
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p.1 #6 · Canon 7D & lens micro adjustment


elyimages wrote:
Les,

I am not sure they used the method you are referring to.
My 70-200, 24-70 & 24-105 all were registered and showed micro adjustment in the camera. My 17-40 was not registered to the camera. I was not told there was a problem with any of my lenses when I was at the service center, and they just finished up the work.
Only after I sent a email asking about it I found out there was a problem.
And I understand that even new lenses will have a problem and need to be sent in.
Just not sure why the other lenes where
...Show more

I have no idea why they would have done a micro adjustment (the procedure available to the camera owner via the menu), instead of doing an actual calibration via the method only available to the service techs. An actual calibration should yield more consistent results. Micro adjustment is more likely to yield different levels of focus accuracy depending on changes in things like the shooting distance.

My suggestion would be to call Canon service and ask to speak with a supervisor. If you explain the situation (and that the lens is under warranty) and if you say that what you wanted done was calibration, not micro adjustment, my guess would be that they will ask you to send the equipment in again and that they will re-do the work.

Actually, what I would ask them to do is this. I'd ask to have them, first, check the lens by itself to make sure it is within spec tolerances. Then, I'd want them to check the body by itself to make sure that it is within spec tolerances. Finally, I'd want them to check the lens and body together to see if any adjustments are called for that would make focus performance more accurate.

Les



Apr 03, 2012 at 01:26 PM
elyimages
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p.1 #7 · Canon 7D & lens micro adjustment


Thanks again Les.

With the acutal calibration method would this affect how the lens works on other camera bodys Like 5d mark II and a 60D? My other question is my 5D mark II and 7D and L glass are all less than a year old. How long is warranty period in which I can have the calibration done for free? And will this method work for two camera bodys?

Dave



Apr 04, 2012 at 10:40 AM
uz2work
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p.1 #8 · Canon 7D & lens micro adjustment


elyimages wrote:
Thanks again Les.

With the acutal calibration method would this affect how the lens works on other camera bodys Like 5d mark II and a 60D? My other question is my 5D mark II and 7D and L glass are all less than a year old. How long is warranty period in which I can have the calibration done for free? And will this method work for two camera bodys?

Dave


Dave,

If any changes are made to the lens during calibration by Canon service, yes, it will definitely affect the lens on other cameras. That is why I suggested that, even though you are sending the body and lens in together, I would request that they first check each independently to make sure that they are within spec tolerances. If each one has its calibration zeroed out independently, theoretically, they should work fine together without need for further adjustment. And, if the lens is properly calibrated, it should not have problems on another body unless that body needs calibration, too. As long as a body or lens is still covered by the 1 year warranty, you should be able to have the calibration checked and adjusted, if needed, without charge.

I'll also point out that I've learned to try not to be obsessively concerned about perfect calibration (or micro adjustment). For example, while a change of few micro adjustment points may seem to make a big difference if I'm looking at 200% on the screen, any difference that will result in even moderately-sized prints will be virtually non-existent.

Les



Apr 04, 2012 at 11:53 AM
arbitrage
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p.1 #9 · Canon 7D & lens micro adjustment


I think you've gotten good answers so far. One point to make is that if you are running 2-3 camera bodies and using a certain lens on all of them then it may be impossible for Canon to properly calibrate them all together. This will really be impossible if you send 3 cameras and 3 lenses (especailly zoom lenses) and want them all to work perfectly no matter what combination of lens + body you choose when shooting. In this case they would have to involve in camera MA adjustment also because it would be like a 1% chance that they could get them all working together in all the possible scenarios. This doesn't even take into account the changes that occur at different subject distances even at the same focal length.

WIth that said though, uz2work is right in that a few points either way really doesn't show up unless shooting macro or very small DOF with supertelephotos. Any wide angle landscape lens isn't going to really matter at all and even your normal walk around zoom won't matter all that much.



Apr 04, 2012 at 12:27 PM
uz2work
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p.1 #10 · Canon 7D & lens micro adjustment


arbitrage wrote:
I think you've gotten good answers so far. One point to make is that if you are running 2-3 camera bodies and using a certain lens on all of them then it may be impossible for Canon to properly calibrate them all together. This will really be impossible if you send 3 cameras and 3 lenses (especailly zoom lenses) and want them all to work perfectly no matter what combination of lens + body you choose when shooting. In this case they would have to involve in camera MA adjustment also because it would be like a 1% chance that
...Show more

Expanding a bit on the thoughts above, whether Canon is doing calibration adjustments or you are doing micro adjustments, getting a "perfect" adjustment requires the camera's sensor plane to be precisely parallel to and at the exact same height as the adjustment target. And, even if the adjustment is made perfectly in such a manner, that adjustment is not always going to transfer to perfect focus in real world shooting. If you are shooting a subject that is not perfectly flat, perfectly parallel to the sensor plane, and precisely at the same height as the sensor, minor focus imprecision is likely to result. Again, though, that minor imprecision is unlikely to make any meaningful difference in an actual print or in looking at the image at normal viewing size on the screen.

Many of us have learned that you can drive yourself crazy trying to get 100% consistently accurate focus. After a period of time of trying for such 100% consistency and driving myself crazy, I ultimately decided to take this approach. Unless I'm noticing consistent front or back focus in actual photos, I don't even bother trying to get "perfection". If I do notice a consistent pattern of front or back focus and if a very carefully and properly done micro adjustment test shows that there is a few points of micro adjustment called for, I will make that adjustment. On the other hand, if I see that the amount of micro adjustment called for is 10 or 15 points, my choice is to let Canon do a proper calibration, which should, again, yield more consistent results at varying distances and in varying shooting situations.

And, regardless of how much AF systems are improved and regardless of whether you are using a 20D, a 7D, a 1Ds Mark III, or a 5D Mark III, those (minor) focus inconsistencies are always going to exist because the precision of the AF system is always going to be dependent on the camera's sensor plane being perfectly parallel to the subject. When we were using 6 or 8 or 10 mega pixel cameras, focus inconsistencies were less noticeable. But, with cameras with more pixels and higher pixel density, the inconsistencies become more noticeable to us because, when we look at pictures from cameras with more pixels and higher pixel density at 100% or 200% on the screen, we are looking at a smaller portion of the complete picture and enlarging that smaller portion to a greater extent. When we do that, we are also magnifying any imperfections to a greater extent.

Les



Apr 04, 2012 at 01:12 PM





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