Chems to clean haze

[greg zinselmeier]

can someone give me a list in order of aggressiveness, chemicals to try to clean off haze from a lens. I have the glass open and awaiting a response. thanks

 

[Tel]

Might as well start with an extreme example. I've had a couple of Mamiya TLR lenses that had really stuck-on haze on their rear elements. Dan Daniel recommended cerium oxide powder so I gave it a try. I got some from a seller on the 'bay; fairly dark red in color (it seems that the darker color has more of the cerium oxide in it). Anyhow, I used it together with Clarity lens cleaner to make up a paste: I would squirt some lens cleaner on the glass, then dip a cotton swab in the powder and rub it on the clouded surface, repeating the process many times over the course of several hours. The results were quite pleasing. I'm not sure if the affected element was coated, and what I may have done to the coating, but the lens focuses just fine now.

It's important to use cotton swabs with wooden sticks so you can apply some pressure. And it takes a lot of patience. But it does work.

 

[Patrick Robert James]

Lens cleaner first. If it is oil then that will work. Alcohol after that. Then acetone. If the glass is etched you may have to resort to polishing. To do it right it is difficult. You can do the down and dirty like Tel though.

It would probably help to say what lens it is.

 

[OAPOli]

Might as well start with an extreme example. I've had a couple of Mamiya TLR lenses that had really stuck-on haze on their rear elements. Dan Daniel recommended cerium oxide powder so I gave it a try. I got some from a seller on the 'bay; fairly dark red in color (it seems that the darker color has more of the cerium oxide in it). Anyhow, I used it together with Clarity lens cleaner to make up a paste: I would squirt some lens cleaner on the glass, then dip a cotton swab in the powder and rub it on the clouded surface, repeating the process many times over the course of several hours. The results were quite pleasing. I'm not sure if the affected element was coated, and what I may have done to the coating, but the lens focuses just fine now.

It's important to use cotton swabs with wooden sticks so you can apply some pressure. And it takes a lot of patience. But it does work.

I also had a Mamiya 55mm TLR lens with baked-in haze on the outside surfaces. Polishing with Cerium Oxide was the only way to remove it. Took a long time. Unfortunately that left lots of micro scratches but the coating resisted. Saw the same thing on the huge front element of a Pentax 6x7 75mm but I returned it.

Usually haze just wipes off with lens cleaner.

 

[Tel]

I haven't seen a lot of lens haze in the middle ground--it usually has either wiped off fairly easily with lens cleaner or a gentle solvent liquid like isopropyl or it was really stubborn and required the big guns like cerium oxide. I used to think that it mostly came from oil migrating from shutter mechanisms to the glass but I was surprised to find on several 65mm Mamiya lens sets that it appeared on both the taking and the viewing lenses.

 

[albada]

Retina IIa often has haze on the two glass surfaces facing the shutter blades. I suspect that the formulation of those coatings made them vulnerable to moisture damage. Nothing I've tried has improved that haze. I guess it's time to try cerium oxide. I hadn't heard of it before this thread.

Mark

 

[Kino]

I have a Rolleiflex 3.5F with a horribly abraded taking lens purchased at a thrift store. I will also try the cerium oxide. Nothing to lose, as it certainly is a shelf queen anyway in it's current state.

 

[Don_ih]

I just bought a Leica Elmar 50 M lens cheap because the front element had fungal etching - which looked like haze but was more like frosted glass. The back of the element looked like ground glass. Anyway, I bought a small bottle of cerium oxide lens polishing compound (amazon) and made a pitch lap (I used violin rosin - which is the same stuff, far as I can tell). After 10 minutes, the frosting was practically gone. I could probably go another 10 minutes and make it even better - and I could probably make another pitch lap for the front of the lens.

Incidentally, before going to that trouble, I tried the "baking powder mixed to a paste with water" thing you'll find on the internet for polishing glasses. It worked - it removed enough of the haze to make the lens sort of usable. But ittook a long time to get any result.

Most of the time, whatever is on the inside of a lens element just wipes off with lens cleaner.

 

[Kino]

Anyway, I bought a small bottle of cerium oxide lens polishing compound (amazon) and made a pitch lap (I used violin rosin - which is the same stuff, far as I can tell).

Don,

When you made the lap, did you form fit it to the curvature of the lens element? Can you go into a bit of detail on how you made the lap?

Thanks.

 

[BMbikerider]

Dan Daniel recommended cerium oxide powder so I gave it a try. I got some from a seller on the 'bay; fairly dark red in color (it seems that the darker color has more of the cerium oxide in it).

It's important to use cotton swabs with wooden sticks so you can apply some pressure. And it takes a lot of patience. But it does work.

That sounds very much like Jewelers Rouge used in the main for final polishing of gold and silver jewellery. It can be used for polishing glass but be very careful. If the lenses are coated it will almost certainly remove the coating!

 

[guangong]

I have used lens cleaner, gently wiping with Q-tip. One lens was almost opaque but haze was superficial on exterior elements only without any etching. Fortunately no fungus. So lens cleaner would be my first choice. Unless one just enjoys tinkering to see what works (nothing wrong with tinkering), if lens cleaner doesn’t work, write off the lens or play with it. Who knows!

 

[Don_ih]

When you made the lap, did you form fit it to the curvature of the lens element? Can you go into a bit of detail on how you made the lap?

I cut a dowel about a 1/4" thick - the dowel diameter was about an 1/8" smaller than the lens. I wrapped masking tape around that to form a dam. Then I melted the rosin and poured it in. Before it was completely set, but no longer really hot, I pressed the back of the lens (which was coated with dish soap and water) against the rosin. Then I scarified the surface to hold the polishing compound. The lens is almost flat at the rear (but not quite). I put a drop of the polishing compound on it, then I rubbed the lens over it, rotating it randomly.

Doing that would remove any coating. It will remove a very very small amount of glass from the surface but retain the curvature. I took some photos with the lens but haven't scanned or enlarged any (negative strip still hanging from the darkroom ceiling).

 

[Kino]

Thanks, Don. My lens is so far gone, it can only improve the performance, so the tips are appreciated.

 

[Don_ih]

My lens is so far gone, it can only improve the performance

That's why I did it. I would hesitate to mess with an expensive lens if it was still usable. But this lens was bathroom-window hazy. And it really improved quickly.

 

[Xylo]

I wonder if using Brasso would work?
It does contain silica powder which is abrasive and it's available pretty much everywhere.

 

[greg zinselmeier]

this is the lens ( rear element of Fujinon 250 mm f/6.7)

 

[Don_ih]

That looks like fungus. If that real element is a cemented pair and that is in the balsam, you're out of luck as far as cleaning goes. If it's on the surface, you may be lucky and it'll wipe off.

 

[greg zinselmeier]

That looks like fungus. If that real element is a cemented pair and that is in the balsam, you're out of luck as far as cleaning goes. If it's on the surface, you may be lucky and it'll wipe off.

Did you or can you see concentric circle band? What do you think that is?

 

[Don_ih]

Did you or can you see concentric circle band? What do you think that is?

I saw that and have no idea. Is it possible it's a cleaning mark of some kind?

 

[Kino]

Those circular marks look like the rubber lens tool or suction cup marks.

Did you use a tool, or several size tools to open the lens? If so, then it appears the haze can be removed with a bit of judicious but careful cleaning.

 

[greg zinselmeier]

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

 

[DREW WILEY]

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.

 

[mshchem]

Hot distilled water and Q-tips

 

[RalphLambrecht]

can someone give me a list in order of aggressiveness, chemicals to try to clean off haze from a lens. I have the glass open and awaiting a response. thanks

can someone give me a list in order of aggressiveness, chemicals to try to clean off haze from a lens. I have the glass open and awaiting a response. thanks

first wipe with a soft cloth and a 3% dilution of hydrogen peroxide bleach. then, clean with a high-quality lens cleaner or 99% polypropylene alcohol. Always apply any liquids to the cloth; never to the lens!

 

[RalphLambrecht]

first, wipe with a soft cloth and a 3% dilution of hydrogen peroxide bleach. then, clean with a high-quality lens cleaner or 99% polypropylene alcohol. Always apply any liquids to the cloth; never to the lens!