# Does CPS fix decentred lenses?



## AlanF (Jan 10, 2018)

One of my lenses appears decentred, with front focusing on one side and back focusing on the other. Does a Canon repair centre fix this type of problem? If so, would it best be done as part of a general service?


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## D. (Jan 10, 2018)

I have sent two lenses in that were decentered for Canon to repair. They did improve both lenses, but neither lens was completely fixed. After those experiences, I carefully check each lens when I buy them so I can return if necessary. Others may have different experiences.


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## Don Haines (Jan 10, 2018)

D. said:


> I have sent two lenses in that were decentered for Canon to repair. They did improve both lenses, but neither lens was completely fixed. After those experiences, I carefully check each lens when I buy them so I can return if necessary. Others may have different experiences.



I would have sent them back for round two of repair, with a detailed note and pictures to explain the problem, making sure to word things politely.... something like “ you have certainly improved it, but I still see the problem, is it possible to correct it further?” A little niceness goes a long way and sometimes inspires the tech to go that extra mile......


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## jolyonralph (Jan 11, 2018)

My old 24-70 was fixed by them, and it came back fine. Now sold on as I have the 24-70 II


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## AlanF (Jan 11, 2018)

Thanks for your replies.


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## bholliman (Jan 11, 2018)

Canon did a good job repairing a decentered 100L Macro lens for me 3 years ago. It was soft on the right side and came back perfect. I sent a.detailed explanation of the problem and prints, I think this helped.


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## privatebydesign (Jan 11, 2018)

bholliman said:


> Canon did a good job repairing a decentered 100L Macro lens for me 3 years ago. It was soft on the right side and came back perfect. I sent a.detailed explanation of the problem and prints, I think this helped.



It doesn’t. It goes on a bench lens test rig, if it meets specs it’s left alone if it doesn’t it is worked on.

I have sent very detailed explainations and test images that have been returned un-looked at, if the lens passes the bench test specs it gets returned. I had a long running issue with a 16-35 f2.8 that took several trips to get sorted out satisfactorily.


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## neuroanatomist (Jan 11, 2018)

privatebydesign said:


> It doesn’t. It goes on a bench lens test rig, if it meets specs it’s left alone if it doesn’t it is worked on.



So, if you have a subtle problem the best path forward is to make it worse before you send it in.


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## bholliman (Jan 11, 2018)

privatebydesign said:


> bholliman said:
> 
> 
> > Canon did a good job repairing a decentered 100L Macro lens for me 3 years ago. It was soft on the right side and came back perfect. I sent a.detailed explanation of the problem and prints, I think this helped.
> ...



I must have gotten lucky and it was either out of spec or the Tech was unusually conscientious


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## AlanF (Jan 11, 2018)

privatebydesign said:


> bholliman said:
> 
> 
> > Canon did a good job repairing a decentered 100L Macro lens for me 3 years ago. It was soft on the right side and came back perfect. I sent a.detailed explanation of the problem and prints, I think this helped.
> ...



The tech was probably a CR member and recognised you.


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## AlanF (Jan 21, 2018)

AlanF said:


> privatebydesign said:
> 
> 
> > bholliman said:
> ...



The tech recognised me as well: just as you wrote, the lens passed the bench test, and they charged me for a service and replaced the lens mount seal, and didn't adjust the optics. The problem, I suppose, is that the specs from Canon and all the manufacturers are lower than we finickety individuals expect.


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## YuengLinger (Jan 21, 2018)

I've only had one disappointing experience with CPS, but it worked out for the best in the end. I sent in an ef 35mm f/1.4L (I) that had, to my eyes, massive amounts of purple fringing even at f/5.6. 

"In spec," the tech said.

Fortunately it was under warranty and I only paid for shipping to them.

So I sold that 35mm and bought a Sigma 35mm Art, which I thought was better than the Canon, but still not satisfying. (Skin tones and other colors just seemed flat, harsh. Functioned fine, adequate AF, though no speed demon.)

And then the 35mm f/1.4L II came out, so out went the Sigma. The Canon version II and I have been living happily together ever since.

All my other experiences, maybe seven or eight in the past five years, have been positive. I've found their techs to be very open minded, especially by phone when they can work with the same gear I'm calling about as I describe an issue.

Best story: Had a 24-70mm 2.8L (I) that had never been impressively sharp, but seemed okay. When it got to be about seven years old, I thought the AF had fallen off a bit, so I sent it in. Came back like a different lens, incredibly sharp and accurate. Amazing the improvement. But then I let my wife use it with a tripod. Crash, smash, and cash (which went to the just released version II)!


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## Mt Spokane Photography (Jan 21, 2018)

Older article, but still correct and pertinent.

http://www.imaging-resource.com/news/2013/11/14/inspecting-an-in-spec-lens-what-does-it-mean-and-could-factory-service-be


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## jhpeterson (Feb 8, 2018)

neuroanatomist said:


> So, if you have a subtle problem the best path forward is to make it worse before you send it in.


That's much like what a friend does with his cameras. He buys the consumer level models and a multi-year protection plan, then uses them for his professional work. When they start to fail, usually just after the next model comes out, he sees that they need to be replaced. Unlike me, who tends to use the last generation pro-grade cameras, he always seems to have the latest stuff.


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