I recently looked at my Raynox wide-angle lens attachment (https://www.bhphotovideo.com/c/product/723496-REG/Raynox_HD_6600PRO_49_HD_6600PRO_49_Wide_Angle_Conversion.html/BI/2855/KBID/3801) I purchased and used in 2014 with my Panasonic HC-X920 (https://www.panasonic.com/mea/en/support/product-archive/camcorder/HC-X920.html) and discovered a very thick film inside the sealed elements. I had noticed that this lens imparted a slight fog to my video whenever shooting in daylight back in ‘14. However, the effect then was slight, and I figured it was an unavoidable feature of using this kind of lens attachment with all the additional layers of glass.

But now (2023) the fogging was way beyond slight, and the attachment was unusable. I decided the best first course of action was to copy what this guy did when he discovered fungus inside the elements of one of his lenses:
https://petapixel.com/2021/09/20/how-to-remove-fungus-between-glued-camera-lens-elements/

What I had was not fungus, but I still thought this was my best choice. This is what it looked like before cleaning:
https://www.dvinfo.net/forum/members/41782-albums258-picture958.jpg

I got myself a vacuum chamber from Amazon (caught an 80% off sale!), some 99.9% pure alcohol, and proceeded to drown my lens in alcohol under vacuum, twice. The second round was a multi-day soak, followed by a multi-day dry out. The result was very good, and I’d say it was returned to its original condition. That is, I can still notice a diffuse lightness when using the lens in direct light.
https://www.dvinfo.net/forum/members/41782-albums258-picture961.jpg

But now I can’t un-see the fogging that remains. When examining the lens in bright light, I can still see an uneven film. (It may be residue from the alcohol.) I believe I have only two choices:
1) Break the lens housing open to access the inner surfaces directly, figure out the best method of epoxying it back together, or
2) Follow the same method as before, but this time use acetone, which cleans better and does not leave a residue.

Method 1 is not so crazy at it might sound because A) this is a wide-angle lens, and it will be more forgiving when it comes to re-building it than a telephoto lens, and B) other than an acetone bath, I don’t have any other options. Either use a slightly fogged lens or break it open and hope for the best.

But method 2 seems like the best choice for right now. It is non-destructive, can’t make it worse, and might clean it up completely.

However, I’m not so sure about the, “Can’t make it worse,” part, and these are my questions to the forum:

Will the acetone remove (or partially remove) any coating the lens might have?
Will acetone remove the paint from the housing, possibly depositing it back down on the lens?
Is there something about acetone that might make this idea ill-advised?

If anyone has any advice on breaking open & rebuilding a sealed lens (method 2), I’ll gladly take that advice also.

Thanks!

Acetone can attack some plastics. It can also remove some paints. You may want to test a drop or two on any plastic or painted lens components before submersing it in the acetone.

Acetone fumes are pretty potent. Be sure to wear proper personal protection equipment. I always wear nitrile gloves, safety goggles and a respirator in addition to using it in a well ventilated area.

Thanks for the tips. I will definitely not do this in my kitchen. The alcohol was bad enough.