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All images © Bob Atkins
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Topic: Infinity adjustment? (Read 18081 times)
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Bob Atkins
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Doesn't sound like there should be any camera movement under those conditions unless you have the lens mounted on a bowl of jello!
What's your alternative? Switch to Nikon? That's going to be expensive and I've heard complaints about Nikon lenses and service too.
I'd give Canon what they want (camera and 1.4x) and ask them to send you their test images before they return the lens if they say that everything is as it should be.
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Frank Kolwicz
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I did exactly what you said, the camera and 1.4x were shipped the same day I talked to Canon.
The representative's reply to my request for their test images was flat refusal - "we don't do that". She also claimed that the tech detected "slight motion blurring". No mention was made of the comparison shots made hand-held with a 100-400, at 400mm, that I included, which show what a minimally acceptable level of sharpness should be.
The tripod setup was at the back of my concrete garage floor: not only maximally stable, but sheltered from any possible wind. If that lens can't produce a critically sharp image under those conditions, when could it?
It occurs to me that maybe this lens was damaged (I bought it used), as Bob suggested, and that they aren't repairable, if the damage is bad enough, or at least not repairable at a price Canon is willing to charge (out of warranty) and have it known just how fragile they really are. Corporate sandbagging of equipment faults, does that sound familiar?
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Bob Atkins
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If it was me I'd bug them on the test images. Why won't they provide them? Don't they take any? They can't be proprietary. If I had a lens I was really unhappy with I'd demand to see some image that they shot that they considered acceptable. If the tech rep said "we don't do that", my reply would be "then can you connect me with your supervisor". Not sure what I'd do if they said "we can't do that". I'd try to get the name of their supervisor at least. Last resort would be to ask for an address or email address where you could send complaints/questions.
I can't see any reason why they can't supply test shots. It may not be their policy or standard practice to do that, but that doesn't mean they can't. They must be taking test shots if they wanted the camera. You can certainly test a lens on its own without a camera using and optical bench and the right targets and optics, but I don't see how you can check it's working with the camera without actually taking shots with the camera.
I don't know what you sent them in the way of test shots. To detect camera motion you'd really want something like an image of a Siemens star in the center of the field and look for decreased resolution in the direction perpendicular to the motion. You're basically looking for different levels of sharpness in different directions in the center of the field (where astigmatism is zero). It would be pretty damn hard to get camera motion with the lens on a decent tripod, mirror locked up, remote release, 1/2000s shutter speed etc.
I'm not saying that they are wrong, maybe something is going on I don't know about, but if they came to conclusions about the image that differed from mine, I'd at least want a technical explanation of what they were basing their conclusions on.
I can see their side too. I'm sure they get complaints about cameras/lenses from users who don't know how to use them or what to expect from them, so they may tend to be a little wary of such complaints, even when they are justified. I very much doubt that there's any corporate conspiracy to hide defects and problems.
Lenses like the 600/4L are made to take hard professional use. I doubt there's anything that would make such a lens "beyond repair to original quality" unless a tank drove over it.
It's a pity there's no independent 3rd party professional testing lab you could send a lens to and get back an optical quality report. Of course such a lab would likely be pretty expensive, plus you'd still have to get Canon/Nikon or whoever to accept their test results and there's always a question of what does and doesn't fall within the normal lens to lens variation and what the lens should be. If you tested 100 lenses of the same type, one of them would be best and they can't all be that good, but the variation should be small. One of them will also be worst of course...
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Frank Kolwicz
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The images I sent them were the .cr2 versions of the one I posted here - a B&W checkered card on a neighbor's driveway about 150 feet away, across from my garage, and the same setup done with the 100-400L on the same camera hand-held at about the same magnification, so at about 1/2 the distance. 3 of each with the focus shifted and re-focused between shots. Those images clearly show a lens that cannot achieve a decent level of sharpness and I agree that seeing "slight softness due to camera movement" in those images would be impossible, swamped as they are by bad focus.
As far as I have ever heard, and I've been a Canon user for more than 25 years, Canon never gives out any information about problems until they can't dodge them anymore and this silent repair policy is in line with that total secrecy about what they are doing or have done with OUR equipment. Canon authorized repair shops are also forbidden to give out much information under non-disclosure agreements in order to become authorized. That's full-fledged corporate, cover your ass, secrecy, whether you believe in it or not.
Nikon does the same thing, so wipe that smug look off your faces, fanboys!
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Bob Atkins
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I think Canon don't acknowledge problems until they are pretty sure it's a design or manufacturing problem when it comes to a defect in a lens that warrants a recall and free fix, but they do do that. There was the rear aperture stop in the 24-105 that was replaced due to flare issues I think. There was also a fix for the 75-300 IS to do with differences when the camera was held horizontally and vertically. I'm sure I remember other examples, but those were the two on lenses I owned.
I don't think there is a general design issue with the 600/4L IS. There are thousands of them out there and very, very few complaints.
I've found Canon to be quite good at acknowledging that a particular lens has problems. That actually sent a 300/2.8L I owned back to Japan for repair and testing and replaced a bunch of the optics. Then again though, I was able to actually talk with the tech staff at Jamesburg by visiting them.
I hope you can resolve your problem. If you can get them to give you a better explanation and to send you test images, it would go a long way to resolving the issue. I really don't know why they seem reluctant to do that.
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« Last Edit: June 14, 2014, 11:17:57 AM by Bob Atkins »
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Frank Kolwicz
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UPDATE:
I heard from Canon this PM and was told that the tech and the service person were going to do some field tests with my camera/1.4x/600L (I hope they have fun) following the regular bench tests. I also hope this lets my lens get fixed this time.
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Frank Kolwicz
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High hopes here.
It's been two days since the Canon repair people said they were going to do some field tests with my 600, 70d and 1.4x and there's been no response. I presume that, if they had gotten decent images, I would have heard immediately, so hopes are rising from this battered and dejected soul who has been without a fully functional right arm since I broke the first used 600mm lens.
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Frank Kolwicz
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Update: remember the masks that adorn old-fashioned theaters - comedy and tragedy? That's where I'm at.
I got the lens back yesterday (the camera and 1.4x are in another box taking a different route) and, after a delay of two weeks when the lens went somewhere (otherwise why did it take so long?) and then back to Irvine for return to me I'm happy to say that it now actually focusses, sharply.
On the other hand, now the lens no longer has IS and AF can't be shut off! It makes one wonder, or it makes ME wonder, how the hell that got through final inspection?
I do have to thank the Canon service reps who handled the case this time and listened to me on the phone and didn't just put it through as another regular item to be processed. The woman who took my call listened, without interruption, to my entire rant on how this lens and my previous 600/4 were routinely passed though their repair service (6 times) without the least improvement in focus, but maybe I finally got somewhere only because it came back significantly worse than when it went in and couldn't focus at any distance or frequency. Maybe the lack of critical focus just wasn't enough for them to do anything or, maybe, the US repair service can't handle something that involves realigning the optical system, not even the main center in New Jersey and that might explain the more than a week of silence and delay after the Irvine center was supposed to have run extra tests with my camera and extender and my sample photos to show how bad it was.
This lens has been out of my hands since May 5th - on it's way to Canon repair and back and out again and now back again to be shipped out again next week. I can only hope that fixing the AF and IS doesn't screw-up the optics when I get my hands on it in the future.
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Johnny
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What a mess!!! Don`t give up!
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Frank Kolwicz
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Thanks, Johnny, but at some point you have to make choices.
I've got the lens back and there is some improvement, especially versus the poor optical performance I got after the last "fix", but the lens is nowhere near as good as an old, beaten-up one I rented last year - that lens produced beautifully sharp images 9 times out of 10, mine only produces barely acceptable images 1 time in 10. Analysis of the image files shows that focus is bouncing all around the subject, even a high-contrast black and white grid target in full sun, which should be the easiest thing for AF to grab onto.
Using LiveView, things are better, but that's no help with moving subjects as the focus is too slow and sometimes hunts the full range of focus before settling down and that takes a couple of seconds while the subject walks out of the frame and has to be found again and focus hunts again, etc.
It's a total waste of time to send it back again, Canon is uninterested in or unable to bring this lens back to how it performed when new and I think this may be the general case for the supertelephotos: break them and good luck to you in restoring optical performance. Mechanically, yes that works, but optically. . .
The way things stand now, I can't rely on getting any kind of critical focus with one or two frames; if I can't shoot at least a couple of dozen, there is little likelihood of finding a usably sharp image. Now I have to try to find uses for unsharp images, as that is what I have, mostly with this lens or hope to use my 100-400 instead, which can be relied on to get good focus almost every time without LiveView.
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Frank Kolwicz
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Much ado since the last message.
While dicking around on the web looking for info on telephoto technique (I am a pessimist and always think this problem is my fault, first) I accidentally found a scientist who knows a thing or two about optical performance (I'm withholding his name, as he may not want to be deluged with other such problems) and he had me do some specific kinds of test images. On review of the image files he said that the lens has specific kinds of aberrations due to either a misaligned optical element or "wedging".
I joined Canon Professional Service and then sent those files, some field test shots and a new batch of images of my cross-hatch test target along with target files from a rental 500/4LIS(II) for comparison with the lens, 1.4x and camera body back to Irvine. The difference in performance between my 600 and the rental 500 was very obvious! Needless to say, but I'm saying it anyway, the comparisons were done under identical conditions.
It finally has come back fixed. It is not quite as sharp as the 500/4, but produces much more usable images than before and handling it is giving me that pain in my shoulder again - I have come to enjoy that pain instead of the stomach cramps the repair service has given me.
To all apologists for Canon service I have to ask: why did it take all of this effort to get what should have been routine in dealing with a lens repair - optical performance? Do ordinary users who don't qualify for CPS (or think to join it) always get short-shrifted on service - doesn't our money entitle us to the same quality service a CPS member gets for the same financial outlay?
Of course I'm pissed! It has cost me 2 years of lost productivity and photo opportunities, thousands of dollars in shipping costs and thousands of dollars in lost equipment costs since I broke that first 600/4LIS(I), gave up on getting it repaired and had to do it all over again with another used 600/4 with the same kind of problem.
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