Spent years cleaning lens elements with isopropyl alcohol until a Leica tech told me to stop

Had a customer bring in a 50mm summicron with haze last month. I grabbed the 99% IPA like always. He about lost it. Said I was stripping the coating over time, especially on older glass. Wouldn't have believed him but he showed me his own work and a comparison under bright light. Sure enough the coatings on his older lenses had this faint rainbow damage. Switched to using distilled water and a tiny bit of dish soap now. Feels weird not using alcohol but the results look the same. Anyone else made this switch or still using IPA?

2 comments

2 Comments

davis.ruby19d ago

Switched my thinking after this exact thing. Used IPA for years on everything, thought it was the only way. Then a buddy showed me his damaged Pentax Takumar coatings. Looked exactly like you described. Rainbow haze that wasn't there before. Now I just use distilled water and a microfiber. Feels wrong at first but the glass comes out just as clean. No more alcohol for me.

the_linda19d ago

Wait, isn't using 100% distilled water basically just giving your lenses a fancy bath? I tried that once and ended up with more streaks than a teenager's bathroom mirror, so maybe my microfiber game is just weak. Honestly though, after hearing stories like this I'm scared to even breathe on my vintage glass too hard.