Dust inside lens - DPChallenge Forums

Canon EF-S 18-55mm f/3.5-5.6 IS

01/14/2005 07:57:54 PM · #1

Newbie question - I have some kind of dirt inside my Sigma 105mm macro lens. I have done every kind of cleaning possible, but now need to have this problem resolved professionally if I ever want to enter a macro shot in a basic editing challenge again. :-)

I have never had a lens cleaned/refurbished before. Does anyone have a recommendation for who can clean a lens like this, and do you know approximately how much it might cost? Or should I do something else entirely, such as throw it away and buy a new Canon 100mm? Thanks for your help!

Konador

Canon EOS-500D Rebel T1i

01/14/2005 08:11:11 PM · #2

Don't throw it away, send it to me :P

01/14/2005 08:13:44 PM · #3

So if I were to send it to you, what steps would you take to clean that internal dirt? You know, theoretically? ;-)

Canon EF-S 18-55mm f/3.5-5.6 IS

01/14/2005 08:14:53 PM · #4

Normally, dust inside a lens will not have a noticeable effect on shots unless there is a terrible lot of it. Have you verified that it does affect your shots? Can you take a pic of what it looks like?

Konador

Canon EOS-500D Rebel T1i

01/14/2005 08:16:13 PM · #5

Originally posted by PhilipDyer:

So if I were to send it to you, what steps would you take to clean that internal dirt? You know, theoretically? ;-)

Step 1) Sell on ebay (forgetting to mention dirt)
Step 2) Get money
Step 3) Close email account so I don't get complaints
Step 4) Buy a new lens

scottwilson

Canon EOS-350D Rebel XT

Canon EF 28mm f/2.8

01/14/2005 08:20:06 PM · #6

Originally posted by kirbic:

I would agree that a small amount of dust will have little impact on the image. A lot depends on how much dust is in it. One big piece of dust is not as bad as a whole lot of very small pieces of dust.

nsbca7

Mattel Barbie Photo Designer Digital Camera

01/14/2005 08:38:06 PM · #7

Originally posted by scottwilson:

Originally posted by kirbic:
Normally, dust inside a lens will not have a noticeable effect on shots unless there is a terrible lot of it. Have you verified that it does affect your shots? Can you take a pic of what it looks like?

I would agree that a small amount of dust will have little impact on the image. A lot depends on how much dust is in it. One big piece of dust is not as bad as a whole lot of very small pieces of dust.

That is if it is dust at all.

01/14/2005 09:03:35 PM · #8

It's a lot of small pieces of dust (or mold, or mud, or kryptonite, etc.) and they become more noticeable the higher the f-stop. At f/4, they're basically invisible, but the DOF is extremely shallow for most macro shots. At f/45, everything is in great focus, including the numerous dark particles on the inside of the lens.

I just want to know if there is a place that cleans inside the lens glass and about how much that costs - and if it's worth it. If it's not worth it, then all of you are warned not to buy a Sigma 105mm macro lens on eBay for the next 2 weeks. ;-)

Mattel Barbie Photo Designer Digital Camera

01/14/2005 09:27:43 PM · #9

Sounds like the best course of action would be to send it to Sigma. I would think that they would have a flat charge for cleaning, and could tell you right off what it would cost you.

nsbca7

01/14/2005 09:45:09 PM · #10

Originally posted by kirbic:

Sounds like the best course of action would be to send it to Sigma. I would think that they would have a flat charge for cleaning, and could tell you right off what it would cost you.

If it is fungus then sending it to Sigma may be a waste of postage. I sent them a Nikon mount Sigma 50-500 with fugus. When I talked to them on the phone they said they would clean it for about $150. When it got there they said the coating was damaged on the elements and that it would be too expensive to fix. However they would keep it as a trade-in and give me another for just $795 more.

I only paid $800 for the thing to begin with.

I described it very honestly, put it up for sale on Ebay with hopes of getting at least $300 and sat back and waited. Final bid was $745. And the guy emailed me two weeks after he got it to tell me how happy he was. Honest.

01/14/2005 09:55:27 PM · #11

Thanks, everyone. I guess the best thing to do is call Sigma and ask them about it.

Here are some sample pics, in case anyone has more insight:

f/4 - No specs visible. See, it even blends right into the page. :-)

f/45 - Whole lotta specs going on

f/45 with extreme editing for spec clarity

Mattel Barbie Photo Designer Digital Camera

01/14/2005 09:58:35 PM · #12

Originally posted by nsbca7:

...I described it very honestly, put it up for sale on Ebay with hopes of getting at least $300 and sat back and waited. Final bid was $745. And the guy emailed me two weeks after he got it to tell me how happy he was. Honest.

LOL, just goes to show that everyone's expectations are different. I'm actually amazed that there are 50-500's out there that already have fungus. I guess in very wet climates, stored improperly... I've never actually seen a bad case of fungus myself.
Isn't it normally pretty easy to tell fungus from dust? doesn't fungus usually grow in a telltale pattern?

nsbca7

01/14/2005 10:10:50 PM · #13

Originally posted by kirbic:

It starts out looking like little specs of dust. Then they grow.

I take all my good junk into the Alabama River swamp with me. I had it less than a year before it started growing. This model Sigma lens is not sealed well at all.

I worry about my EF 600/4. If it screws up I'll buy another.

01/14/2005 10:14:07 PM · #14

Philip,
Just for completeness, you have verified that you sensor is clean, correct? I recommend if you have not cleaned it recently, do so, and take pics again.

Message edited by author 2005-01-14 22:15:23.