Thought ultrasonic cleaning was overkill for lens elements until I tried it on a fungusy 50mm
I picked up a beat up Canon FD 50mm f1.8 at a flea market in Portland for $15, and the rear element had fungus etched so deep I figured it was a paperweight. A guy on a repair forum swore by his $80 ultrasonic cleaner with distilled water and a drop of Dawn, so I gave it a shot and the haze came off in about 4 minutes with zero coating damage. Has anyone else had luck with ultrasonic on cemented groups, or am I risking the balsam separating if I push my luck?
Tbh ultrasonic is a game changer for fungusy glass, saved a cheap Helios of mine the same way. Just don't leave it in too long on cemented groups, the vibration can work the balsam loose if you get greedy.