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pivot
30-Jun-2010, 03:38
Hello,

I just received my first LF lens. It is a used Schneider APO-Symmar 180mm in good condition.
The problem is that there is a decent amount dust visible. Is this something I should worry about or can this be neglected? Unfortunately I can't test this lens yet as I am still waiting for a camera...

Thanks

norly
30-Jun-2010, 04:12
Why not clean it? I assume its on the inside of the glass and not only in the middle section... I dont think some smaller dust on the front glass is anything to worry about but a fair amount seams a it much.

pivot
30-Jun-2010, 05:47
I already unscrewed the two pieces tried to blow it all away. But that didn't help much. The dust is within the construction.
Should I send it back?

norly
30-Jun-2010, 07:36
Since the dust isn't i focus, you shouldn't be able to se it on the ground-glass (on the camera) or on a print. But I can imagine thats its annoying to know its there.

Cant promise but it should work fine to use the lens.

Caivman
30-Jun-2010, 08:20
do not send it back. Lenses are the easiest to clean so long as you take time, dont' force anything, and use the proper tools. As long as your shutters are working fine, cleaning lens elements should be your top priority to get this thing back up to par.

pivot
30-Jun-2010, 08:34
do not send it back. Lenses are the easiest to clean so long as you take time, dont' force anything, and use the proper tools. As long as your shutters are working fine, cleaning lens elements should be your top priority to get this thing back up to par.

How is it done and what tools are needed?

rdenney
30-Jun-2010, 08:54
It is unlikely that even a moderate amount of internal dust will have a visible effect on your pictures. UNLESS...you let the sun shine on that dust. Good shading keeps that from happening.

Rick "who owns few lenses without any visible internal dust" Denney

shadowleaves
30-Jun-2010, 10:32
How is it done and what tools are needed?

Spanner wrench, high-purity ethanol, some cotton balls, and some patience...

Caivman
30-Jun-2010, 10:57
Spanner wrench, high-purity ethanol, some cotton balls, and some patience...

listen to this man.

also, there are many many tutorials out there on how to remove lens elements. I suggest you watch/read as many as you can before you start or risk destroying your lens.

Kevin Crisp
30-Jun-2010, 11:02
I takes a ton of internal dust to affect the image. If the interior is not fogged, leaving it alone is often the best course.

But if the threads are not damaged, and you are careful, you can use the Grimes wrench to undo the retaining ring and clean it internally. Be very careful to note the order of things when you take it apart, sometimes there are spacers and you need to put them back in the right way.

pivot
30-Jun-2010, 11:32
It's nice to hear that a certain amount of dust won't effect the image quality. I contacted the seller nonetheless and will see what he has to say. This lens had been declared to be in "A" condition (which it is apart from the noticeable dust) and cost 450.

Personally I don't feel very comfortable with the idea of cleaning the lens by myself. I just don't trust my hands that much...

RK_LFteacher
2-Jul-2010, 09:58
Before anyone gets too far into a lens, let me comment this: The primary cause of loss of sharpness in a lens and or one side sharper than the other, is decentering of lens elements. Taking elements out of groups is really an exercise best left to people with a 'columnator' who can realign the lenses/groups. As commented above, nothing inside a lens is in focus. But a few microns of decentering can cause a lot more problems than a few dust specks.
Schneider and Rodenstock are even concerned with photographers carrying their cameras over their shoulders on the tripod, and the pounding, compounding by the lever of the tripod, damages the shutter slighly-decentering the groups and sharpness of the lens. Then they get a call or complaint. My lens isn't sharp!
So be very careful or send into Schneider to get cleaned and checked.
Rod

Jack Dahlgren
2-Jul-2010, 11:39
There are typically 4 easily accessible surfaces that a user can clean.
The front and rear surfaces are simple and can be cleaned in the typical manner.
Unscrewing the rear element exposes two more surfaces. Removing the rear element in a typical modern lens involves twisting it with your hand in all of the lenses I've ever had and is almost always part of mounting a lens in a different lens board. It is no more difficult than unscrewing the top off a beer bottle, but you should take special care in screwing it back on to make sure you are not cross-threading. It is also important to note if there are any spacers being used and assemble just as it was before. As long as you are not forcing things, it is hard to imagine what the problem would be.

With the rear element you can open the shutter and aperture and clean the back of the front element and the front of the back element. This should eliminate most of the dust you see.

As for being worried about trusting your hands, don't worry too much. Your hand won't scratch a lens. If the materials you use to clean the lens are softer than glass they won't damage it either. First, blow off any dust. This may be sufficient. If not, use a soft brush, cloth or cotton ball to lift any dust off the lens. Once that is done you can use a cloth or cotton ball dampened with alcohol to remove any smears, oil or other sorts of stuff on the lens. Let it dry and put it back together. It is really no different than cleaning a pair of glasses or even washing wine glasses. If you want to practice first, clean one of your windows or a mirror.

Going beyond that involves disassembling the lens so I'd not recommend that unless you know what you are doing and have the ability to get it back the way it was.

bvstaples
2-Jul-2010, 11:45
Have you even contacted Schneider about cleaning the lens or having them clean the lens? Or taken it to a reputable shop for cleaning? I'm in Southern California, and I know of a few places that will do it for a reasonable price. It looks like you're in the EU. Just curious...