Effects of Damaged Lens Coating?

[Tim Halloran]

I just scavenged a funky Sony/Canon TV Zoom Lens 17-102mm 1:2.1, off an old university-equipment Sony DXC 1610 video camera. The thing looks pretty good cosmetically and seems to function great—c-mount threads are clean, everything rotates and moves smoothly.

 

However, even though the front lens element appears to be scratch free, the coating has been completely rubbed away from the center to about the outer ¼ inch, leaving a bluish “halo” around the edge. It being an ex-school cam, I can just imagine how much “lens cleaning” this thing went through.

 

Question is, how and by how much will this effect the image that I get from it? I just plan to use it on a Bolex for experimental work so it’s not that big of a deal. I’m just kind of curious before I shoot some tests with it. I know what coating does, and I’ve heard of people actually trying to remove damaged coatings, but I’m wondering what a lens with this coating “halo” will do.

 

And btw, while you’re here—anybody have any experience creatively playing around with one of these lenses on a Bolex? It has a very fluid push-pull zoom that, together with the ultra smooth focus, might make for some interesting experimental effects, I would think. Any stories would be appreciated.

 

Tim