12-21-2011, 10:47 AM
[quote name='Frank' timestamp='1324458988' post='13967']
I don't know if the coating of a lens is easy to harm. I used to clean my 24-85mm f2.8-4 basically following the correct steps. However, after the cleaning I found that near the boundary of the glass the caoting got two tiny "white spots". I wonder if the coating has been damaged by the cleaning process. That made me to think that probably the coating of the 24-85mm is too weak, but I never know if my thought was correct and I even didn't know if that was really a coating damage. After that cleaning I put a UV on the lens and never checked it again. Since that I also became nervous in lens cleaning and put a UV to every my lens except the 50mm f1.8D.
Frank
[/quote]
I never use UV filters (ever, no UV to filter). They can do more harm than good. I have no coating or lens surface damage (you can't damage the coatings with cleaning, they are super hard and very stuck). Not on my "new" lenses (5 of them), nor on my nikkor MF lenses from the 60's/70's (5 + 2 of them).
The "spots" you noticed can't have been caused by normal cleaning of the lens. You do have to clean the UV filters too, don't you? Have you noticed any cleaning damage on them?
I don't know if the coating of a lens is easy to harm. I used to clean my 24-85mm f2.8-4 basically following the correct steps. However, after the cleaning I found that near the boundary of the glass the caoting got two tiny "white spots". I wonder if the coating has been damaged by the cleaning process. That made me to think that probably the coating of the 24-85mm is too weak, but I never know if my thought was correct and I even didn't know if that was really a coating damage. After that cleaning I put a UV on the lens and never checked it again. Since that I also became nervous in lens cleaning and put a UV to every my lens except the 50mm f1.8D.
Frank
[/quote]
I never use UV filters (ever, no UV to filter). They can do more harm than good. I have no coating or lens surface damage (you can't damage the coatings with cleaning, they are super hard and very stuck). Not on my "new" lenses (5 of them), nor on my nikkor MF lenses from the 60's/70's (5 + 2 of them).
The "spots" you noticed can't have been caused by normal cleaning of the lens. You do have to clean the UV filters too, don't you? Have you noticed any cleaning damage on them?