Chems to clean haze

[wiltw]

You simply want to dissolve whatever creates the film coating the accessible surface of the lens...wipe with a cotton ball dampened with a bit of isopropyl alcohol (not dripping wet with alcohol) Alcohol is a very commonly used 'solvent' in the manufacture of semiconductors, for 'cleaning' steps in the manufacturing process.

You should not use something involving mechanically abrasive 'polishing'

Polymers/epoxies are used to cement elements together on modern lenses, but at one time balsam was often used. The haze might be from the balsam, or it might be from lubricants used in the lens focus mechanism

 

[Don_ih]

If the "haze" is between cemented elements, there's no hope. The fact that you see those circles from some kind of tool suggests you might be able to get rid of the "haze". You've tried alcohol, peroxide, q-tips, and prayer. So you have nothing to lose by using the cerium oxide.

 

[OAPOli]

Thanks kino, it does look like suction cup marks. Cerium oxide is on the way. Below is a list of things I’ve tried. All have not been able to remove haze. However to a degree it has improved. But I think the suction cup marks are “etched” on the glass. hydrogine perixode and full strength ammonia, nor isopropyl alcohol, nor acetone, nor hand lotion, nor lime away /// has worked

Try to confirm the correct surface where the deposit is present. It can be hard to determine without removing the element.

 

[greg zinselmeier]

the rear group is a single /air gap with a cemented double. i took out the cemented double. & looking at a cemented double, . . . yes indeed it is difficult to correctly Identify which surface has the haze. I feel confident that the one of the four ( the outside surface facing the GG, once assembled) the other 3 are still in question ----if its either of the two that are cemented together, I guess im out of luck.

 

[Xylo]

Brasso? - on a lens element ? The cure would be worse than the disease. You need a much finer, gentler polish than that. Silica is basically fine sand. One should also be able to get special cleaners including cerium oxide from Edmund Scientific, or really, any serious lab supply house.

I don't know... was just an idea like that.

 

[Xylo]

if its either of the two that are cemented together, I guess im out of luck.

I remember reading that some people repair those by fully separating the lenses, removing the balsam using a solvent and then using glass adhesive (I think UHU makes some) to put them back together.

When the lens is essentially garbage to begin with, there's not much to lose by attempting something like that.
You just have to make sure they are properly aligned by looking through them at a rectilinear target.

Those glues usually cure under UV rays.

 

[Geiginni]

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:

1. Kodak lens cleaner (the ammonium carbonate stuff)
2. Anhydrous isopropyl alcohol
3. Acetone
4. 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.

 

[Andreas Thaler]

I once had two lenses with a heavy coating that I couldn't get off with either isopropyl alcohol or surgical spirit.

Finally Aqua purificata dissolved the stuff.

I was amazed.

 

[Taylor Nankervis]

100& isopropyl alcohol and microfibre cloth as a start.
I have heard of some folks using toothpaste to attack haze. Might be fine on old, uncoated lenses, but definitely not on modern-era MC lenses...

99% polypropylene alcohol

What is that??