Ultrasonic Cleaning—Does it damage lens coating?

[Justin Low]

Hi!

I have a question. I currently use an ultrasonic cleaner for cleaning body tops, small metal parts, e.g those with knurling, etc.

I've not tried putting lens elements into it, and I'm not sure if it'll damage the lens coatings, especially those on earlier Leica lenses, which are reputed to be softer.

My current 'wet' method of cleaning lens elements involves gently wiping it with contact lens solution under running water, treating it sort of like a giant contact lens. While the risk of scratching should be rather low with this method, the risk of the element slipping out of my fingers and down the sink is rather concerning.

That said, I clean my glasses (which are coated) in the ultrasonic cleaner and notice no ill effects.

What do you think?

 

[FallisPhoto]

That said, I clean my glasses (which are coated) in the ultrasonic cleaner and notice no ill effects.

What do you think?

If the lens is suspended in the solution, and is not in contact with anything harder than plastic, no problem, although this isn't going to do much more than just hand cleaning it. On the other hand, if you drop it into the tank, so it rests against the bottom (and thus much more vigorous vibration is imparted to it), it will come out really clean, but with lots and lots of microfractures. Ultrasonic cleaners work really well for cleaning shutters, but I think they are more trouble than they are worth for cleaning lenses. I also think that too many people forget that if you clean a shutter in an ultrasonic cleaner, it doesn't just end there. You have to change the solvent and clean it again, or the crud in the (now dirty) solvent just redeposits when it dries, and you still have to take the shutter apart and (precisely and very sparingly) lube it afterward.

BTW, glasses usually have plastic lenses and are not ground with anything even remotely like the precision of camera lenses.