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04/03/2005 06:32:56 PM · #1 |
I wondering if anyone has ever taken a lens apart before. I've got a Canon Ultrasonic 75-300mm lens that's sluggish, and sometimes needs a boost for the autofocus to work. There are times when a press the shutter half way and I can hear and see the lens trying to focus, but it's like it is stuck. It almost feels like it just needs a good cleaning. Has anyone ever tried to clean the inside of a lens?
It's not the greatest lens but it's the only long lens I have right now. Camera shops want an arm and a leg just to look at it. I'm mechanically inclined and wouldn't be opposed to tearing into it myself, if someone could tell me it's not that difficult. I would hate to take out the screws and have pieces falling out all over the place (hate it when that kind of thing happens).
Any suggestions?
-RCB |
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04/03/2005 07:04:56 PM · #2 |
| Did you happen to be focusing on a solid color, perhaps a blank wall or paper or something? Your camera detects contrast to help it focus, so if theres no contrast in the picture, your camera will have trouble focusing. Having your camera set on spot AF makes this more likely too |
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04/03/2005 07:10:45 PM · #3 |
When I was a kid I did, and with an axe too.
I wanted to burn holes in my flip-flops using the glass. The experiment was a success. Someone wasn't too happy though.
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04/03/2005 07:14:12 PM · #4 |
perhaps you should buy a really really cheap lens (garage sale, fleamarket etc) and pull IT apart first.
Might learn something from it! |
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04/03/2005 07:16:39 PM · #5 |
My advice is, don't tear into it unless you're prepared to write it off and replace it if you fail. Given the orignal cost of the lens, and it's current value considering the AF issue, giving a self-repair a try might not be a bad idea. You may find that you don't need to disassemble much to fix whatever is stiffening the AF mechanism, or then again you might be faced with major surgery.
There's a guy over on DPReview that disassembled his 70-200/2.8 IS to replace parts in the IS mechanism (yikes!). Don't know if he ever successfully reassembled it, but some of the disassembly involved desoldering electronic connections, and was definitely not for the faint of heart.
If you do disassemble, make sure that if you need to remove any of the optical elements, make registration marks so that you can reassemble them in precisely the orientation they were in, it makes a difference!
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04/03/2005 07:24:54 PM · #6 |
I would suggest a professional camera repair person. It may just need cleaning which could be only $50 to $75 bucks.
Cam Pro, Indianapolis 317-862-2869 does ours |
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04/03/2005 08:16:21 PM · #7 |
Go for it, it's fun. I must have opened dozens for various reasons over the years. I've probably gotten a few of them back together and working too. But it's still fun. I repaired a Takumar 80-200 macro with a cheap jewler's screwdriver set that I bought from a small hardware store on a side street of Tirana, Albania. There was a screw looose inside that I had to get to to tighten. I only had two other lenses with me, both wide angle, so it saved the trip.
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04/03/2005 08:51:32 PM · #8 |
I was photographing a bike race and got hit with a flying bike, or rather my lens did. Broke the lens. Now it's serving a different purpose.
Message edited by author 2005-04-03 22:45:24. |
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04/03/2005 09:25:06 PM · #9 |
| Disassembly of a lens is like kissing it away. The list of what can go wrong is almost endless from breakage, cleanning, alignment and dust and fingerprints. I did once, and I am pretty mechanically inclined. My biggest success was with the old Swiss watches. But the lens is just different altogether. I did once and then used the impaired lens in an opaque projector. Pay the fee, it will come back like new and above all highly polished. |
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04/03/2005 10:23:32 PM · #10 |
Thanks for the comments everyone. Looks like I'll be making a trip to the camera store some time in the future.
-RCB |
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04/04/2005 05:13:15 PM · #11 |
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04/04/2005 05:19:32 PM · #12 |
A small story for you all.
I dropped a Sigma (canon fit) lens a few weeks ago. To my horror there was a rattling inside. The lens still worked (kinda). I had to manually pull the lens to zoom and there is a nastly click when manually focusing.
Anyways I opened the top to try and find out what was rattling. A small piece of plastic about 2 mm squared fell out which I think is one of the teeth from the gears or motor. I could only get so far then I didn't have a screw driver small enough.
Use my experience and DON'T DROP LENSES, hehe
Justin |
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04/04/2005 06:02:18 PM · #13 |
I took my Sony F707 apart to fix a loose focus ring. I researched it first and found good step by step instructions to do it. It was a little different in that I didn't have to mess with the actual lens elements themselves but it still made me a little nervous. In the end it worked out perfectly but I'm not sure I would have done it had I not had the instructions to follow. This is mainly because I would not have wanted to lose the use of my camera by messing up. I don't think it is such a big deal to try repairing your particular lens yourself. It will either go well or it won't and if it doesn't you still have the option of having an expert repair it. This is provided that you don't damage something worse in the process but it sounds like you know what you are doing with this kind of thing.. Sounds like you are curious about this stuff anyway and that it won't be the end of the world if something went wrong. Brand new and very expensive equipment with warranties would probably be a different story.
T |
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04/04/2005 09:07:47 PM · #14 |
Originally posted by graphicfunk:
Pay the fee, it will come back like new and above all highly polished. |
Where?
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