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EFS 17-55 USM corner blurriness: experts' opinion needed !

Started Nov 2, 2014 | Questions
MayaTlab0 Senior Member • Posts: 2,985
Re: EFS 17-55 USM corner blurriness: experts' opinion needed !

70d IF wrote:

A few customers will complain and they will repair their equipment.

The problem is that I've personally never had a decentered lens that a repair centre was able to properly repair. In fact some lenses seem to have zero adjustment capabilities other than to replace the molded parts the elements sit on. So far only exchanging the defective lens has been effective, but the hassle is so annoying (especially when they tell you that it's "within manufacturing tolerances") that I've started to do what I didn't want to do : I buy online several copies and only keep one, if there is at least one that isn't badly made.

I've heard some positive stories regarding a service centre ability to repair decentered lenses, mainly from Canon, but having to send a lens for repairing a decentered element remains one of the things I dread most (with sensor / AF module / mount hardware and software calibration).

Interestingly decentering seem to come in batch from my experience. I've had massive issues with Olympus recently, and out of seven 25mm I tested, only three weren't decentered to a significant degree, the other four had a tilted focal plane (or sphere, if you want to take into account field curvature), much closer on the left side, with some variation, sometimes rather the lower left side, sometimes the upper left side, but always closer on the left (note : the bodies were fine). All the defective ones had earlier serial numbers, all the good ones later numbers. BTW, Olympus service has been utter rubbish, in fact they managed to go straight to my personal top 1 of the worst customer service I've ever had in my (short) life.

Just another Canon shooter
Just another Canon shooter Veteran Member • Posts: 4,691
Re: By "within spec", he may mean

Rick Knepper wrote:

Just another Canon shooter wrote:

Rick Knepper wrote:

that in comparison to the 24-105, this lens has three sharp edges vs. none.

It does not.

You saw this - - didn't you?

Yeah, a great tool - how didn't I see it sooner?

BTW, I owned the 17-55 for years and now I am using the 24-105 on FF.

 Just another Canon shooter's gear list:Just another Canon shooter's gear list
Canon EOS 5D Mark II Canon EF 15mm f/2.8 Fisheye Canon EF 35mm F1.4L USM Canon EF 50mm f/1.2L USM Canon EF 135mm F2L USM +4 more
plantdoc Veteran Member • Posts: 4,339
Re: EFS 17-55 USM corner blurriness: experts' opinion needed !

I tried factory service for just 1 lens and problem was switched from top to bottom. Others have been returned for exchanges. However, I do resent being the QC center for a $500+ lens. With the high precision computer controlled manufacturing and testing equipment available today, this shouldn't be an issue.

Greg

OP 70d IF Regular Member • Posts: 155
Re: EFS 17-55 USM corner blurriness: experts' opinion needed !

MayaTlab0 wrote:


As previous posters have suggested, the "brick wall" + 180° upside down test is a good start to analyse a lens for a number of decentering issues, especially if it's at least moderately rigorous (example : same exposure).

So, I am back, 6 months later !

I finally managed to get the Canon technician to repair my lens, after long discussions on the phone. He sent the lens back saying that he had reduced but not totally resolved the problem, which looks true. At 55 mm the problem is gone, at 17 still visible, but to a lesser extend.

Since I have no brick wall at hand, and the upside down test is a bit acrobatic for me, I did this.

What do you think ?

 70d IF's gear list:70d IF's gear list
Pentax K100D Canon EOS 80D Canon EF 85mm F1.8 USM Canon EF-S 17-55mm f/2.8 IS USM Tamron SP AF 17-50mm F/2.8 XR Di II LD Aspherical (IF) +4 more
irm Veteran Member • Posts: 3,105
Re: EFS 17-55 USM corner blurriness: experts' opinion needed !

Try to find an independent lens/camera repairer that will do a complete investigation for you.

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 irm's gear list:irm's gear list
Canon EOS 10D Canon EOS 5D Mark IV Canon EF 50mm F1.4 USM Canon EF 50mm F1.8 II Canon EF 135mm F2L USM +9 more
plantdoc Veteran Member • Posts: 4,339
Re: EFS 17-55 USM corner blurriness: experts' opinion needed !

I wonder if a decentered lens can be fixed. I have experienced too many and now I test and reject any lens with the problem.

Greg

OP 70d IF Regular Member • Posts: 155
Re: EFS 17-55 USM corner blurriness: experts' opinion needed !

plantdoc wrote:

I wonder if a decentered lens can be fixed. I have experienced too many and now I test and reject any lens with the problem.

Greg

I did it once, my current lens is already my second copy. The first one was worst...

 70d IF's gear list:70d IF's gear list
Pentax K100D Canon EOS 80D Canon EF 85mm F1.8 USM Canon EF-S 17-55mm f/2.8 IS USM Tamron SP AF 17-50mm F/2.8 XR Di II LD Aspherical (IF) +4 more
OP 70d IF Regular Member • Posts: 155
Re: EFS 17-55 USM corner blurriness: experts' opinion needed !

irm wrote:

Try to find an independent lens/camera repairer that will do a complete investigation for you.

I actually find it usable now. I just would have liked to know if my lens is worst than a typical one. Did you have a look at my new test ?

 70d IF's gear list:70d IF's gear list
Pentax K100D Canon EOS 80D Canon EF 85mm F1.8 USM Canon EF-S 17-55mm f/2.8 IS USM Tamron SP AF 17-50mm F/2.8 XR Di II LD Aspherical (IF) +4 more
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