How to tell if a lens is scratched/damaged? (1 Viewer)

ColonelBlimp

What time is bird?

• Jul 10, 2009

• #1

I've just cleaned the 'big eye' of my Diascope 85, and looking through a jeweller's loupe at it, just outside the area I cleaned there is a strange little grey mark, about 1mm long, like a long smear.

It doesn't sparkle, it doesn't look 3D, it just seems to catch the light a little when the ambient light reflects off the lens. Could this be a scratch, or coating damage? What else could it be? I don't want to clean it to make sure, for fear of damaging it further.

 

ColonelBlimp

What time is bird?

• Jul 11, 2009

• #2

Anyone?

 

Keith Dickinson

Well-known member

Opus Editor

• Jul 11, 2009

• #3

Could be a water stain, in which case it should clean off with solvent.
Do you see anything when using the scope normally? If you don't I'd be less worried than if you were getting flare from the mark.

 

B

BoonHogganbeck

Well-known member

• Aug 2, 2009

• #4

I cleaned my Diascope 85 after a very dusty excursion, and despite being as careful as possible, left a big scratch in the coating right across the center of the lens. So, if that big beautiful lens of yours is scratched, I feel for you. It hurts.

But if you don't plan to resell this at any point, and don't get any more scratches in it, I would put it out of your mind. I doubt you'll even notice the blemish when looking at wildlife.

 

Kevin Purcell

Well-known member

• Aug 2, 2009

• #5

Sounds more like smeared junk with the brightness against the AR coating.

Try washing with liquid dish detergent, water and a clean fingertip then rinse with deionized or distilled water and dab dry.