AR Coating on modern PAMs

Hi2all,

I recently took a close look at a 1950 Luminor with domed sapphire crystal and discovered that the AR Coating was scratched. The way this was determined is by the shadow the scratch left on the dial. Even more interestingly, the scratch was very linear - almost as if it were machine-made... .

Then I was told that OP only coats the inner-side of the crystal... ! Is this true? Others have suggested that OP coats both sides (or did in the past)and the AR has a shade of blue.

Does anyone know what the current AR-coating policy is?

Thanks for any feedback you may be able to provide!



Traveller - Genève / Melbourne / Miami / Wien