First time post here, but I discovered something last night that was very useful.
Had an uncoated pre-war Xenar 3.5 with haze on the back element that could not be removed through my normal methods, which typically are, in order of increasing need/desperation:
- Kodak lens cleaner (the ammonium carbonate stuff)
- Anhydrous isopropyl alcohol
- Acetone
- Ammonia-Hydrogen peroxide mix
After all those failed, I tried a bit of the non-abrasive Scotch Brite pad (the white one) with some high-quality light machine oil, and that did the trick. I then finished up with alcohol to remove the residual oil.
I will keep this in my back-pocket for future issues (on non-coated lenses). Again, it must be the soft non-abrasive Scotch Brite.