Hazy lens cleaning

I picked up an old screw mount 135mm f/2.8 lens (named Rexatar) recently. I

understand that this lens is post 1970 but I think you folks may be able to

help, since lots of people in this forum have repair experience.

 

The lens is extremely hazy. Since I got it almost free and nothing to loss, I

took it apart from the rear mount; then, I found one surface of the 2nd glass

element is very hazy/foggy (I don�t believe it is fungus but I could be

wrong). I have tried Kodak lens cleaning fluid, KALT lens cleaner, even 409

glass cleaner, and had no luck. When it is wet, the glass is clear. When it

is dry, the haziness comes back.

 

I am open to any experiment/suggestion. Thank you.

 

Kevin

It sounds like it's been etched by something, probably a fungus of some kind, and if so, it's not salvagable.

Sometimes just an agressive wiping with a microfiber cloth will work where nothing else does.

Have you tried vinegar?

Go the pharmacy and get some 91 percent isopropyl alcohol. If the haze is caused by lubricants from inside the lens that have evaporated and then redeposited on the lens, this might work. If it's a fungus, this won't help.

Good luck.

You've tried most of the standard cleaning techniques. I've never tried this, but some people have reported good success with Pond's cold cream. No idea why, but apparently it can polish this stuff out- sometimes.

Toothpaste is the next level up the "polishing" tree.

 

But it is probably fungus etching.

Element 1 - "Why are you so hazy ?"

 

Element 2 - "I don't know."

 

Element 3 - "There's a fungus among us."

Run your finger across the lens surface with your eyes closed. Does it feel "smooth"? If not, then odds are ﾗ as others have suggested ﾗ that your problem involves etching, or "scratching," of the lens. At home, you simply cannot fix this problem. Even if it does feel smooth, this may be the problem, but, you have a chance that it's just some type of "build-up" (which can, perhaps, be cleaned). Take it to a repair shop; maybe they'd look at it and (for free, or a nominal fee) tell you what they suspect is the problem (and whether or not resolving it would be financially "wise").

 

Even if everything fails, try the lens; you might be surprised by how "acceptable" your results turn out to be.

Try all of the non-abrasive approaches above; if none of them work then you have nothing to lose by trying to polish off the haze. Toothpaste is the first level of abrasive polish, it's not too aggressive.

 

I have an old Kowa lens that developed a serious haze within one layer of its antireflective coating. It defied all forms of cleaning, but finally improved substantially (though not totally) after a good deal of polishing with silver polish. The coating in this case is very durable and hard, and all of the polishing had no visible effect on the effectiveness of the coating. This is not always the case, however: some coatings are so soft that they are destroyed by the slightest touch. If you're working with a coated lens and you don't polish enough to visibly remove the coating, you know that you have not affected the curvature of the element surface. Once the coating is removed, (in addition to losing the benefits of the coating) you no longer have a guide as to the surface curvature. It is generally, however, safe to polish off a surface haze as long as you stop as soon as the lens is clear.

As others have noted, its probably etching. However, the cleaning solution I have used to great success is ammonia and hydrogen peroxide - it does buble a bit, but if its cleanable, it will work well.