Cleaning the inside of lenses

[mttmrphy]

I'm sorry if this has been discussed before... I searched and couldnt find anything useful.

I recently cleaned all of my lenses and noticed a small spec inside my Canon 28-135mm IS USM.

http://webpages.charter.net/mttmrphy/pictures/dust.jpg

Is it safe for me to carefully disassemble this and blow out the spec?

[Scottes]

I truly would not do this. It would be off to Canon.

But more importantly - can you see it? Take a picture of a blank white wall at widest and narrowest apertures. Can you see the spot in the resulting images? That speck may not be in the path of the light.

However, you'll always know it's there, it could move, and it may cause some weird flare or something. But if you can't see it from the test above then at least you don't have to send it in right this moment.

[PhotosGuy]

Is it safe for me to carefully disassemble this and blow out the spec?
No, as in NO! Send it to Canon. You don't know what it is & it's possible that it could prompte the growth of mold. Summers almost here - why wait?

[Belmondo]

If you read back through some of the older threads, you'll see one person who actually thought about trying to hook the lens up to a vacuum cleaner. (don't look at the April 1 threads....this person was serious!). Needless to say, we all advised against such a procedure, but we never heard the end of the story either, so it might have worked. I suspect that if he really did try it, he’s probably still rooting through the dust bag to find all the various bits and pieces of that lens.

Scottes is right. If it's not showing up in your pictures, it's probably more aggravating than detrimental. If it does show up, then Canon is really the only place I'd consider sending it, as annoying as that prospect might be..

[justme_dc]

Unless it effects your picture quailty (see test above) or really drives you cazy I'd just leave it alone. If you want it out have the lens professionally serviced. I've got gobs of dust in some of my older lenses and even a lens with a chip in the front element from flying debris at a AMA event but I leave them as they are becuse there is no effect on picture quality.

[Bruce Hamilton]

Is it safe for me to carefully disassemble this and blow out the spec?
I agree with the concensus... send it off to Canon, especially if it's still under warranty. I suspect it was there when it went out the factory, and their quality control department missed it.

[mttmrphy]

If its not under warranty what does canon usually charge to clean a lense?

[Ken Fong]

If it is no longer under warranty...
I don't know how much they will charge but it might not be worth it.

My photography teacher said it is quite common to have specs inside a lens that will have no effect on your picture quality...you can even have dead bugs in there. He said the important thing is not to allow mold to grow in there.

I personally would never consider opening a lens unless I knew what I was doing and in some sort of a clean room.

[IndyJeff]

If you open that lens be prepared to consider it a paper weight from now on. That is of course unless you have been to a Canon factory training session for lens repair and have the necessary specialty tools to do the job.

[G3]

Good advice here. Listen to these guys. DO NOT OPEN THAT LENS!!! I've had lenses with chips on the front elements, scratches on the front elements, little thingamajigs rattling around in them, all sorts of stuff..and they still worked great and it had no effect on the image. Back when I got my first pro-level camera (Pentax LX) one of my lenses had a tiny little screw rattling around inside it. Every once in a while, it would get stuck in there somewhere and quit rattling around...then I would just bump the lens until I shook it loose again and go ahead and shoot. I figured as long as it wasn't stuck in the aperture mechanism, it wouldn't hurt anything. As long as they still work and the image is still good, I don't even bother getting them fixed. If you open it up and try to fix it yourself, 90% chance it's toast after that.

[Joytek]

I am the person who used a vacuum cleaner on my brand new 17-40. there was a very large bit of stuff on the inner surface of the front element when I got my lens, and I was trying to suck it out.

It worked.

but yu need to be extremely careful not to intriduce even more dust into the lens. So, unless you can see the debree, or some sort of it's manifestation in your pictures......don't waste your time and just let it be.

I am not very lucky with my equipment. my 10d has five fairly large dust bunnies BETWEEN the low-pass filter and the sensor. They only show up occasionally, when the conditions are just right. Canon A/S told me to get lost, so I had to just ignore them for the past 9 months. Such is life.

My 70-200 f4 also arrived wit ha big chunk of something on the inside, but since I store my lenses on their sides in my bag, the debree must have been loosened off by vibration from the car rides and handling. I have never seen it again, so it must have fallen somewhere into the lenses's inner gears. no harm done.

remember that all this phot gear is just as imperfect as everything else in life. that, however does not mean that it will prevent you from getting some awesome pic nonetheless. just go out, forget about all the little glitches and flaws, and lose yourself in the rush of teh actual process of 'hunting" for that unforgettable shot(s).

the world is full of dust and filth, and nomatter what kind of equipment you use, it will get f**ked up eventually. that's the reality of it. enjoy it while it lasts, don't let it bug you.

Wojtek.

[Belmondo]

I am the person who used a vacuum cleaner on my brand new 17-40. there was a very large bit of stuff on the inner surface of the front element when I got my lens, and I was trying to suck it out.

It worked.
Wojtek.

Thanks for the update, and I'm glad it solved your problem. I still don't think I could recommend the process to anyone else, but I admire your courage!

Tom

[ron chappel]

I work on lenses for a hobby but even i wouldn't take apart one of those unless it had a serious problem.There's alot of rather technical knowledge needed for fixing those types of lenses.

A spec that size can't possibly effect your pictures in any way...and here's the final argument that should convince you-actually cleaning the glass elements is the HARDEST part of repairing lenses.Even the slightest little specs left inside gets magnified!!
They don't effect the lens performance but it sure is a let down to do a perfect job of cleaning and find that a lens shows more dust afterwards :oops: :oops: :oops:
Only consider this type of thing if the lens is cheap or simple to work on and has something serious like fungus

[PhotosGuy]

Ron - I work on lenses for a hobby but even i wouldn't take apart one of those unless it had a serious problem.There's alot of rather technical knowledge needed for fixing those types of lenses.

Do you know if they introduce a neutral gas like low humidity nitrogen into the lens as they do (I seem to remember) into rifle scope optics? If so, that would be another factor. It’d be ‘instant soft focus’ if the lens steamed up when the temp changed!
And the diaphragm might freeze at low temps, too.

[EoSD30fReAk]

DON'T DO IT!!

you'll end up with more dust than you have now!! :!:

i've repaired a lot of 28-135IS lenses and even i have trouble getting them clean with the right equipment 8)

so just don't do it,

[Greystonebone]

:D I have tried the vacuum cleaner trick..... and............... OMG it works, the dust particle that was making my photo's dotty is now gone....

[cyberblue]

:D I have tried the vacuum cleaner trick..... and............... OMG it works, the dust particle that was making my photo's dotty is now gone....
Clearly vacuum cleaner trick is the winner!!! (perhaps with shopvac or something more industrial)
But seriously guys, I wouldn't recommend doing it on a lens that I couldn't afford to mess up.

[Double Negative]

Dishwasher. Pots and pans cycle. Be sure to use heat dry.