Anyone ever tried to "fill" a scratch on a lens?

We are having a discussion in another thread about scratches on front elements and if they affect IQ at all. The main thing everyone agrees on that it would affect is contrast and flare.

I'm wondering, has anyone ever tried to "fill" the scratches with glass repair stuff they have for windshields? It seems that if you could fill them they wouldn't refract as much light. My only concern would be if it would react with the multi-coating somehow and make a big mess of the front element.

Just thinking out loud. What do you guys think?

Chris

Anyone that has done that would presumably be not too fussy about image quality.

Nick

Nick_C wrote in post #2755448
Anyone that has done that would presumably be not too fussy about image quality.

Nick

And maybe not willing to admit it!

Having tried that windshield stuff before I have never been able to get a seamless, invisible repair even though the product claims that that is what I would get. So, I would venture a guess that it would make it worse. I did see a new produce called Liquid lens repair for glasses, but I have never tried that stuff.

If there were actual scratches in a lens, it might be better to fill them with non-reflecting black material rather than leave them open. I'm thinking that the filling would reduce bouncing light rays and there would be less probability of flare or haze in the images.

I dont' fill scratches in my UV filters - I just buy a new one.

If it's a recent EF lens of any real value, odds are Canon can repair the damaged outer lens for a fraction of the cost of a new lens anyhow.

$100-200 to repair the front element of a 24-70L.

I know nothing about lens maintenance (but that has never stopped me expressing an opinion before), if there was a scatch in a lens would the correct treatment not be to grind it out (if ecconomically justified) or bin it - er... I mean re-cycle.

gjl711 wrote in post #2755460
Having tried that windshield stuff before I have never been able to get a seamless, invisible repair even though the product claims that that is what I would get. So, I would venture a guess that it would make it worse. I did see a new produce called Liquid lens repair for glasses, but I have never tried that stuff.

Having had this done professionally for me (paid for by my auto insurance company who waived any deductible), I can state that it truly is seamless. There is no visible evidence of a seam that a junction between glass and the polymer makes...there is merely the original very evident crack in the glass which you can clearly see, which is prevented from growing larger by the invisble bandage formed by the polymer!

OP, somehow I don't think you were thinking of Bondo on the lens surface, were you? It certainly would stop and flare and diffraction effects!

Uh, no, not Bondo. Although, like you said, that certainly would stop any flare problems.

I was talking about the same stuff you seem to be. The polymer stuff they use to fill cracks and chips in windshields. My thought is, if a scratch is a problem because it refracts light differently than the rest of the surface (because of the edges created by the scratch), then wouldn't filling it help? It of course would never be like it was originally, that's a given, but it seems a filled scratch would be better than an unfilled one. Wouldn't it?

Just thinkin'
Chris

MrChad wrote in post #2756136
If it's a recent EF lens of any real value, odds are Canon can repair the damaged outer lens for a fraction of the cost of a new lens anyhow.

$100-200 to repair the front element of a 24-70L.

for that cost does they repair the damaged outer element or replace it by a new one ?

I think by now you have the impression that it might not be such a good idea

I'd rather just try out that 70-200 and use it as it is if it works fine ... there is not a big risk that the crack in your lens will get bigger and you lose your roadworthiness approbation

Best regards,
Andy

They replace the damaged glass.

Only feasible repair would be to re-grind the lens - and that would change the physical nature of that element, affecting the AF, internal refraction etc - needing the entire lens to be recalibrated.

Hahaha ... I'm not sure that re-calibration would solve the problems you get by grinding away the top layer of your front element...

Best regards,
Andy

NWShooter wrote in post #2756435
Uh, no, not Bondo. Although, like you said, that certainly would stop any flare problems.

I was talking about the same stuff you seem to be. The polymer stuff they use to fill cracks and chips in windshields. My thought is, if a scratch is a problem because it refracts light differently than the rest of the surface (because of the edges created by the scratch), then wouldn't filling it help? It of course would never be like it was originally, that's a given, but it seems a filled scratch would be better than an unfilled one. Wouldn't it?

Just thinkin'
Chris

with any filling materials ,they use heat which might damage the coatings in the area around the scratch thus end up with a larger damaged area in the IQ.