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Lens Back from CLA -- A Few Questions


dwrz

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I just got back my lens from CLA after it had moisture in it from a shoot out in the rain (more info here).

 

The good news is that the water marks are now gone. Looking through the lens, the glass is clear. However, with a flashlight, there is now considerably more dust than before the incident, and there is some kind of strange grain (looks like sand), in front of the aperture blades. Is this normal after CLA? Will it affect image quality? I looked through with the flashlight when I first received the lens from the seller (might have some photographs somewhere), and it was pretty much spotless then.

 

Here are some photographs:

elmar1.jpg

elmar2.jpg

elmar3.jpg

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Thanks. I just sent off an email. I figure I should probably have done that first. But yes, I made sure to use my lens pen brush on both elements to make sure it wasn't on the surface.

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Could they be silica beads for removing the moisture? A burst bag perhaps of part of the CLA process? Maybe one can dismantle the lens (as per the 35 pre asph thread) and simply drop out the beads then reassemble and your done? Perhaps someone braver than me knows how to unscrew this lens easily?

 

Regards, Lincoln

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Well, I got a response from the technician, and he is saying that what I'm seeing is not dust, but coating damage. He is offering a full refund if I am unhappy with the work, which is very nice. My question is-- how can I tell? Should I send this off for another repair, with the chance that I will pay for no significant improvement, or accept that this is a damaged lens and use this as is?

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I do not believe it is coating damage. The particles look too big. The coatings are extremely thin on the lens surfaces < 1um which is less than a 1/25th of a thou (i.e < 0.04mils in USA). It looks like it is behind the first lens. This lens is 4 lenses in 3 groups the back 2 being stuck together. It is more likely to be lubricant that has got wet then dried out and formed into beads. Not sure why they gave it back to you in this condition. Perhaps they didn't dismantle the lens but put it in an oven instead? Was it Leica that you sent it to or a private camera tech in USA? I would hope if you sent the info to Leica they can say the same and quote you for dismantle CLA getting it back to you as good as new.

 

Just don't go diving with it again, and if you must put a rubber on it with the end cut off to let in the light while protecting the lens body!

 

Best of luck,

Lincoln

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I took a light to my other lenses (digital, that I have had from almost 2 years, and another for just 5 months) and both seem to have dust on the inside as well, though I did not take too much of a look at the size/quality.

 

I sent it to a private camera tech. I really don't know what to think. What I think I will do is wait until I get my 35mm, then send it in to Leica to see what they say. I really hope it is just that I am inexperienced, rather than having laid my limited cash on an improper repair.

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I might be able to throw some light on this. I had a lens with a very similar look, even worse. I thought it was very bad dust invasion, it looked just like it but a technician had a close look at it with a magnifier and told me it was indeed corrosion of the coating :(. Interestingly enough shots I take with that lens don't appear affected if I stop down, but the problem will apparently only get worse with time.

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I might be able to throw some light on this. I had a lens with a very similar look, even worse. I thought it was very bad dust invasion, it looked just like it but a technician had a close look at it with a magnifier and told me it was indeed corrosion of the coating :(. Interestingly enough shots I take with that lens don't appear affected if I stop down, but the problem will apparently only get worse with time.

Hi

 

I shoot in rain a lot and use (the Elmar) when condensation is likely, so I'm not happy with OP's bad experience.

If you strip a lens you need a clean chamber for reassembly. It seems to be difference from screwing on a UV/IR filter, lenses are dust magnets.

If your lens has bad dust internally best to ignore, little effect on photos, improves dig cam shots. If it has fog ship to technician ASAP.

 

Noel

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