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Cleaning Dew Spots on Corrector Lens..Best way??

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#1 mpesik

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Posted 08 April 2013 - 10:16 PM

Hello.
I have a 14 inch sct and it has a few dew spots.
How doe's one get rid ...Right?
thanks.

#2 Mirzam

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Posted 09 April 2013 - 06:45 AM

First, don't clean the surface unless it is fairly dirty. If you worry too much about a few dew spots then you will be cleaning more often than needed. There is always a slight risk of doing damage when cleaning optics.

The chief risk is that a hard particle on the surface will cause scratches when you wipe the glass. Use an air blaster (manual squeeze type not canned air) in conjunction with a soft brush or cloth to dislodge any visible particles. A Q-tip moistened in alcohol can be used to loosen any stubborn particles.

Once the risk of particulate caused scratches is eliminated, I use either Zeiss optical wipes, which are lens papers saturated with alcohol, or alternatively, Viva paper towels with alcohol to gently clean the lens surface. Do not use acetone because it will dissolve any paint or plastic that it contacts and smear this over the surface.

I find that the alcohol works well, but you will have to make several passes and the final pass may still leave some residues. The finishing touch is to breath on the lens and wipe away the last residue with a clean Viva paper towel.

Viva paper towels are cheap, soft, and oil/perfume free. There may be other alternatives but test them out first before applying to your expensive optics.

JimC






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