Dropped $300 on an ultrasonic cleaner and it changed my lens repair workflow

I had been struggling with fungus and haze on old glass for years, using q-tips and solution by hand. Finally broke down and bought a decent ultrasonic unit. My first job was a 50mm f/1.4 from the 70s that looked like a swamp. Ran it through three 5-minute cycles with a good surfactant and the elements came out spotless. Cost me $300 but it saved me maybe 6 hours of scrubbing on that one lens alone. Has anyone else found these things actually cause damage to certain coatings if you run them too long? I keep hearing mixed opinions.

2 comments

2 Comments

iris9276d ago

That first lens you did sounds exactly like a Minolta 58mm f/1.4 I had that looked like pond water inside. I found three 5-minute cycles with a good surfactant was the sweet spot too, but I had a rough scare with a Canon 50mm f/1.2 LTM where the rear coating started peeling after just two cycles. I talked to a camera repair guy who swears by keeping the water temp under 40c max for older german coatings like the ones on those 70s lenses. The damage happens when the cavitation gets too aggressive on certain types of single-layer coatings, especially if there's already micro-scratches from previous cleaning attempts. So I run everything on a test piece first if I can, and I never go over three cycles without checking the progress.

spencer_coleman6d ago

Pond water" is a fantastic visual, thanks for that. Sounds like those German coatings are more fragile than my last relationship. Guess I'll stick to three cycles max and hope my lenses don't rebel.