Last ditch effort to remove all front element coating from lens. Best "chemical" ? Acetone?

[geminihc]

an old lens i have has a few very surface level scratches on the purple coating, but it causes some blurring in the center of the photo where the scratch is. enough for me to not really use it at all, so i want to try to remove ALL the coating altogether.

i was thinking of using nail polish remover (acetone), anyone tried this?

thanks!

 

[Ron Poelman]

causing your problems ?
If you really don't care from here,
you may want to add rather than remove stuff.
Couple of wipes of clear nail varnish to fill the scratch, hair dryer
and cross your fingers ?

--
Ron.
Volunteer, what could possibly go wrong ?

 

[Leonard Migliore]

an old lens i have has a few very surface level scratches on the purple coating, but it causes some blurring in the center of the photo where the scratch is. enough for me to not really use it at all, so i want to try to remove ALL the coating altogether.

i was thinking of using nail polish remover (acetone), anyone tried this?

Your basic old lens coating is magnesium fluoride. Not soluble in anything. Acetone won't touch it but it will ruin any paint or plastic it hits.

 

[Urban Toreador]

causing your problems ?
If you really don't care from here,
you may want to add rather than remove stuff.
Couple of wipes of clear nail varnish to fill the scratch, hair dryer
and cross your fingers ?

 

[Ron Poelman]

If try rain-x first if going that route. It works by filling microscopic cracks
--

car polishes/repair gels would go close too.

 

[fishy wishy]

an old lens i have has a few very surface level scratches on the purple coating, but it causes some blurring in the center of the photo where the scratch is. enough for me to not really use it at all, so i want to try to remove ALL the coating altogether.

If the absence of the coating causes blurring, why would you want to remove the coating?

 

[Robert Evagelista]

I was actually going to suggest this
from somebody that don't know anything about glass like me...
This had worked on my Wind Shield scratches... and even at my head lights...
(after a month, need to reapply it)...

Not sure if it will work in a camera lens.

 

[alanr0]

an old lens i have has a few very surface level scratches on the purple coating, but it causes some blurring in the center of the photo where the scratch is. enough for me to not really use it at all, so i want to try to remove ALL the coating altogether.

i was thinking of using nail polish remover (acetone), anyone tried this?

Your basic old lens coating is magnesium fluoride. Not soluble in anything. Acetone won't touch it but it will ruin any paint or plastic it hits.

Leonard is correct. Magnesium fluoride is an inorganic material and unlikely to dissolve in acetone. However acetone will dissolve certain plastics and paints. According to wikipedia magnesium fluoride is insoluble in ethanol (another organic solvent) but does dissolve in nitric acid -- though I strongly discourage getting this latter anywhere near your lens, camera, skin, eyes or lungs.

A few scratches are unlikely to cause blurring, but you could be seeing flare and loss of contrast if some of the coating is missing. Old lenses are designed for film. A well-designed camera sensor reflects much less light than a film emulsion, but what is reflected is largely specular. Light from the centre of the field of view can be reflected back from one or more of the lens surfaces. If this is your problem, removing the remaining coating is likely to make matters much worse - as pointed out by fishywisht.

If scratches are bad enough to cause problems, filling them with black paint is a tried and tested approach which may help.

 

[Landscapeforfun]

lab grade acetone is what most optical mirrors with coatings are cleaned with, that or lab grade methanol. They dissolve the dirt, dust, and crud on the lens very well, but have no effect on the coatings. I assume camera lens coatings are the same.