Cleaning A Lens of Fog

[Ari]

I have a cheap 100mm lens here I'd like to do some macro with, but the inside of the rear element is well-fogged.
I can disassemble the lens and clean the foggy side of the lens, but I'm wondering how to properly deal with fog.
I've read that straight vinegar is the cleaner to use, after which, leaving the lens in a box with desiccant will take care of the problem.
I was going to use distilled water and a scanner wipe, but if there's a better way that you've tried, I'm all ears.

Any thoughts?
Thx in advance

[Doremus Scudder]

I'd proceed by trying more mild solutions first. Clean the element as you would a regular lens surface (i.e., lens cleaning fluid or alcohol and a micro-fiber cloth). Only if that doesn't work would I try more active solutions. A standard cleaning will likely solve your problem.

FWIW, I don't think vinegar (or any kind of acid!) is a good choice for lens cleaning. Others will chime in with suggestions for cleaning solutions, I'm sure.

Best,

Doremus

[Ari]

Thanks, Doremus.
I use distilled water on my scanner glass, I figured I'd start with that.
If it doesn't work well enough, I just found a bottle of Kodak lens cleaner fluid ca.1990. and will try that.

[Peter De Smidt]

This is my favorite lens clenaer: https://www.edmundoptics.com/f/puros...cleaner/12946/
I prefer it to ROR.

[Ari]

Thanks, Peter.

[Drew Wiley]

Do you mean fog between the elements from moisture condensation, like temperature shock, or having the lens too long around dampness? If that is the case, you need a little dessication chamber. Get something like a tight-lid Tupperware container, put in some freshly baked-out silica gel, put the lens in there for a couple weeks, with the lid sealed even more with perimeter tape. Cleaning disassembled elements is a slightly different topic, but already answered.

[Greg]

This is a very "last resort", but using a kit that clears "fog" on headlight covers does in fact work. Again this is a really "last resort" fix to be tried in my opinion. Used it on a junk lens, and it did work, but never got the courage to try it on a slightly fogged brass lens that I once had and used.

[Ari]

Do you mean fog between the elements from moisture condensation, like temperature shock, or having the lens too long around dampness? If that is the case, you need a little dessication chamber. Get something like a tight-lid Tupperware container, put in some freshly baked-out silica gel, put the lens in there for a couple weeks, with the lid sealed even more with perimeter tape. Cleaning disassembled elements is a slightly different topic, but already answered.

Drew, it's the latter; the fog has been there since I bought the lens, but I've not bothered to remove the element until now.
If a simple cleaning (distilled water, lens cleaner, lens wipe) doesn't have any effect, then I'll do as you suggest.
Thanks

[Ari]

This is a very "last resort", but using a kit that clears "fog" on headlight covers does in fact work. Again this is a really "last resort" fix to be tried in my opinion. Used it on a junk lens, and it did work, but never got the courage to try it on a slightly fogged brass lens that I once had and used.

Thanks, Greg; we'll see if it comes to that. It's definitely a beater lens, so I wouldn't hesitate to use the strong stuff if needed.

[Ari]

Here's a photo of the fog; some might call it haze, but it's a filmy coating and I'd like to proceed with caution before any attempt at cleaning.