Moldy oldies

[kalasinman]

Bought an old pair of 12x50 bins for 20 quid. My expectations weren't high, but just wanted something to play with while waiting for the subs to come in. They are Swallow brand and Japanese, probably 70s-80s vintage. Looking backwards revealed light mold on one side and slightly more on the other. Collimation is fine. I can tell no difference between the 2 sides by day or night. Cloud dodging last night to see a star, but looked sharp and fairly free from fringing.

So what is the effect of mold in the intermediate lens? Contrast? Fuzziness? Is it like with a dirty mirror in that it takes a fair amount to have a noticeable effect?

I'm sure I got a fair deal for 20 BTW

[mdstuart]

It is possible with care to clean Mold off the eyepiece lenses if that is where the mold is. Depends how brave you are!

[MAN or ASTROMAN]

It is possible with care to clean Mold off the eyepiece lenses if that is where the mold is. Depends how brave you are!

Maybe Baader Wonder fluid would be an option- please someone correct me if I'm wrong,but I think it has anti-fungal properties that will clean off the 'gunk' and help prevent future re-growth.

[kalasinman]

Sadly the mold is in an intermediate lens.

[mdstuart]

What within the eyepiece group? Just take them carefully out noteing their order! Clean them and put them back in....prisms can also be cleaned but collimation can be a pain...

[kalasinman]

Not in the EP group, behind the objective a ways. As I've tried tem briefly between clouds and the views look ok, I'll count my self lucky. They are sharp and collimated and no fringes. Good enough. I don't want to deal with attempting a collimation.