Canon LTM lens coating deterioration

[PatrickCheung]

I noticed that over the course of a year, my Canon 35mm f2 started getting softer and more flare prone. My girlfriend was playing around with the lens the other day and held it up to a light. She told me she couldn't see through the lens because a whole bunch of dots were blocking the view. She removed the light, and the dots disappeared, the view was clear.

I mentioned this to Youxin Ye, who said that he got a few reports of Canon LTM lenses' coatings deteriorating. He says there's nothing he can do about them without exceeding the cost of the lens itself.

This is more or less just a heads up... I'm sure a lot of them are still fine and will be fine for a few years... but... better safe than sorry, I suppose.

That said, my 35/2 is still a beautiful lens. All the effects of coating deterioration seem to go away at around f4.

 

[Mackinaw]

It's not surprising to hear that the coating of a lens that is 50 years old has started to deteriorate.

John Van Stelten can re-coat lenses at his shop. While not cheap, a re-coat won't cost more than the value of the lens. See this URL:

http://www.focalpointlens.com/fp_intro.html

Jim B.

 

[kermaier]

I don't have a Canon 35/2 lens on hand to look at for size, but please note that John Van Stelten's polishing machines cannot handle glass elements smaller than 3/4-inch in diameter. (E.g., he could not polish/re-coat a Canon 25/3.5 lens, which has really tiny elements.)
Good luck,
Ari