coating coming off lens

I was given a manual wide angle cosina lens which takes surprisingly nice images. On closer inspection I noticed that part of the coating on the front lens had come off or been removed. This is about 25% off of one side. It doesn't seem to affect any of the pics I've taken thus far. I wonder does anybody know of a substance I can use to remove the rest of it without compromising the glass itself?

Thanks.

if it hasn't had an impact on your pictures, why do you want to fiddle with it? Glass is coated for a good reason, removing the remaining coating will not do anything good.

To make the glass more uniform perhaps! Its my intention to be using this lens for indoor pics and I can't see I'll have too many problems with solar flare. Despite not having seen any aberrations to the few images I've taken doesn't mean that will always be the case.

So what would remove the remaining coating safely? I guess someone was careless enough when giving the glass a 'super' clean to have found it. I wonder, what it is?

I've never experienced this problem with any lens, old or new. Are you sure that the coating has come away and that it's not just a discolouration of part of the front element?

[quote="johnriley"]I've never experienced this problem with any lens, old or new. Are you sure that the coating has come away and that it's not just a discolouration of part of the front element?

Hello John, You or anyone who cares to, take a look at this image and you'll see what I'm on about.

http://philmerrin.gallery.netspace.net.au/albums/album01/IMGP4923_cr.jpg

That image looks pretty drastic to me. Have you tried removing the front element to clean it?

It looks as though some pernickety person has been over-enthusiastically cleaning it to the extent that he's removed most of the coating.

Lenses should not be cleaned too aggressively, or too often.

G

The lens itself is not scratched, I've taken the pic in a way to emphasise how that coating has come off. It definitely appears that someone has been over zealous with the cleaning. My guess is some type of solvent has been used. I have tried a dab of petrol (knowing that that won't affect glass) but all it did was clean the lens and not soften the remainder of the coating as I had hoped. With some of the coating off, I would prefer to make things uniform by removing the rest. One thing is certain I can't put it back. Any ideas anyone?

I have a 2x TC that suffered the same as this I found that glasses cleaner (from an optician) successfully removed the remaining coating.

Thanks, I have managed to remove the rest of the coating with turps and a soft cloth between the glass and my thumbnail. It was quite laborious but after 30 mins or so it was all off. The glass now looks pristine (it should its had one hell of a polish) and still has a nice purple tinge - presumably the other surfaces are also coated.