Planning to send my Mamiya lens in for haze removal

[Dave Krueger]

Not to put to fine a point on the discussion, but is repair a necessary option? A quick look on eBay shows a number of 127mm f/3.8 C's for sale in all sorts of conditions. Having had cameras worked on at Midwest, for instance, I can attest that repairs on obsolete equipment at Midwest can be quite expensive.

Unless the lens has some sentimental value, I think I'd bite the bullet and get another one. There are several which list as "for parts", and you may be able to put together a decent lens that way, or have a repair service reassemble it from the collective parts.

Just a thought.

Dennis, I don't have a lot of hope that "for parts" lenses on ebay are going to have glass in much better shape than the one I already bought that was rated NEAR MINT. I may keep an eye open for one, but I'm getting burned out on this problem.

 

[Dave Krueger]

Follow the instructions in post #20 or heat to boiling in a pan of water and boil for 10 minutes, let cool completely, repeat several times over several days before attempting to remove from the mounting.
You may have to wait a week or two after the heatings for the elements to clear.

Trying to get the lens to clear by applying heat has been at the back of my mind since you first mentioned it. I will probably try that since it's clear that even old balsam melts under heat. Also, it's not like I'd be ruining a useful lens if it cracks the glass.

 

[shutterfinger]

Slow indirect heat works best.

 

[itsdoable]

I used boiling water (100C) to separate a doublet that had fungus growing in the balsam. Cleaned it up with acetone after separation (although isopropanol would have been fine). Reassembled with an air space to check the optical property of the lens. Then re-cemented it with UV cured optical resin (same used for fixing stone chips in your car windshields).

 

[Dave Krueger]

Slow indirect heat works best.

I will suspend the lens in a pan of water to keep it off the hot bottom and slowly increase the heat so the entire piece heats uniformly.

 

[Dave Krueger]

I used boiling water (100C) to separate a doublet that had fungus growing in the balsam. Cleaned it up with acetone after separation (although isopropanol would have been fine). Reassembled with an air space to check the optical property of the lens. Then re-cemented it with UV cured optical resin (same used for fixing stone chips in your car windshields).

I applied acetone to the glossy black "paint", but it had no effect, so I'm now pretty sure it's epoxy. Trying to get that thing apart is looking less "doable" every day. I plan to heat it up to see if the Balsam will melt and possibly clear, but I am approaching the "giving up" phase of the project.

 

[Dave Krueger]

I know this is a really old thread, but I stumbled across the contraption I made to boil this lens and realized I never posted a follow-up. I rigged a way to suspend the lens pair in a pan of boiling water rather than letting it touch the pan. I boiled it three times for at least 15 minutes (each) over a period of several days, but never detected any change. I finally got frustrated and gave up.

Shortly after this, I looked through about 20 ebay listings for this lens and all but two mentioned that the lens had haze. Most of the listings rated the lenses at near mint or exc+++++ which seems really counter intuitive to me. Apparently many sellers now rate their lenses according to external physical appearance rather than their optical condition.

On the bright side, I now have a Hy6 and managed to pick up a couple of exceptionally clean wide angle lenses from the Leica Store Lisse ("from Netherlands") on ebay. I'm giving up the larger 6x7 negative in exchange for a much lighter camera and exceptional Schneider lenses. If you're a darkroom printer who shoots architecture or urban landscapes, there is no substitute for virtually distortion free lenses (not that Schneider has a monopoly on low distortion lenses, of course).

Anyway, thanks to all youse who offered suggestions on how to resolve this lens fog issue. Sorry I dropped the ball on following up. I'll keep an eye on ebay. Who knows? Maybe I'll eventually land a clean 127 or 90mm and keep the RB-67 as a studio camera or a backup for the Hy6.

 

[Dave Krueger]

@Dave Krueger Thank you for the follow up! I was hoping you'd try the oven method too. For science!

Haha! I think I just reached burn out on that lens, but it sure is unfortunate to have a lens in otherwise excellent condition that is unusable simply because of one glued pair of elements.

 

[shutterfinger]

Check it again in 3 months, it may have cleared.
Was the pan being heated to keep the water boiling?

 

[Dave Krueger]

Check it again in 3 months, it may have cleared.
Was the pan being heated to keep the water boiling?

Yes, I left the heat turned on and the water boiling the whole time (about 15-25 minutes) and then turned the heat off and left the lens in the water as it cooled down. I did it a couple months ago when this discussion was active. I just forgot about it because of some family health issues. I checked it just now and it is still quite cloudy, but I will keep an eye on it.

 

[Dave Krueger]

If you're a darkroom printer who shoots architecture or urban landscapes, there is no substitute for virtually distortion free lenses (not that Schneider has a monopoly on low distortion lenses, of course).

"Virtually distortion free" might be a little bit of a distortion itself, but I think the distortion of the Schneider wide angle lenses is lower than the Mamiya wides.

 

[shutterfinger]

If the pair is cemented with Balsum then it will eventually clear with heat and time. If the pair was cemented with UV cement then you may have to soak it in Acetone until the cement is saturated then let it dry out completely.

 

[Dave Krueger]

If the pair is cemented with Balsum then it will eventually clear with heat and time. If the pair was cemented with UV cement then you may have to soak it in Acetone until the cement is saturated then let it dry out completely.

The lens is about 30 years old. Was UV cement in use back then? I could certainly repeat the boiling water treatments. With regard to the acetone, the lens pair seems to be encased in a black epoxy (or metal) collar which would prevent the acetone from seeping in. In any case, soaking it in acetone is simple enough as well. It's not like I am going to ruin something that is already unusable. After the last heat treatments, I put the lens back together. I will disassemble it and repeat the heat treatments again. If I could get it to clear without separating and regluing the elements, that would be great.

 

[Dave Krueger]

If the pair is cemented with Balsum then it will eventually clear with heat and time. If the pair was cemented with UV cement then you may have to soak it in Acetone until the cement is saturated then let it dry out completely.

Shutterfinger, Old Gregg's comment made me go back through this thread to refresh my memory. You suggest oven heating in post #40. 325F for 30 minutes, let cool and repeat 3x. If that is more likely to yield results than boiling, then maybe it's time to try that. I'm not sure how accurate the temp control is on my kitchen oven, but I could monitor it with a thermocouple.

 

[flavio81]

Shortly after this, I looked through about 20 ebay listings for this lens and all but two mentioned that the lens had haze.

I own a 127/3.8C with exactly the same problem.

However a friend of mine has the 127/3.8 and it doesn't have this problem.

I'd suggest avoiding this lens...

 

[Dave Krueger]

I own a 127/3.8C with exactly the same problem.

However a friend of mine has the 127/3.8 and it doesn't have this problem.

I'd suggest avoiding this lens...

That's interesting. I would expect more haze problems with older lenses, but I bought a 127mm K/L lens on ebay (which is newer than both) and had to send it back because it too had haze.

 

[Dave Krueger]

@Dave Krueger Thank you for the follow up! I was hoping you'd try the oven method too. For science!

It's now in the oven at 325F as we speak....

You know, it's been two months since I boiled the lens. It's still cloudy, but I don't really know if it's still as cloudy as it was originally. My eyes aren't calibrated to measure cloudiness. Makes me wonder if I'd even recognize an improvement that was anything short of complete (or near complete) clearing.

 

[Dave Krueger]

SUCCESS!!!

The oven treatment did it.

It didn't just get better. The haze is GONE! The haze had a texture and it was slightly worse around the edges than in the center and it lit up brightly when shining a flashlight through it. All that is gone from the center all the way to the outer edges. See picture below. I gave it three cycles at 325F for 30 minutes, followed by a cooldown of several hours after each heating. The haze was still there after the second cycle and I expected it to still be there after the third. The actual temp, as measured with a thermocouple at the lens position, varied. The hottest was 377F immediately after preheat, just before I put the lens in the oven, but after that it varied between 309F and 352F. I left the glued lenses in the metal metal mounting piece (basically a threaded collar). In other words, there was no need to try and separate the glass from the metal ring they are mounted in. Also, there is no apparent damage to the coating.

I did this treatment on the rear lens pair. This 127mm lens has a cemented front pair which also has pronounced haze. I will be doing that one tomorrow. I will try to remember to do before and after pictures.

This should give hope to everyone with old Mamiya lenses with haze between cemented elements. Remember, I sent this lens to a repair shop and they told me they couldn't fix the haze. Removing these lens pairs is not hard and only requires a few fairly inexpensive tools. There are several videos on Youtube by mikeno62 demonstrating the disassembly of RB-67 lenses.

Shutterfinger, thanks for your persistence in motivating me to try this stuff in the face of my skepticism. You made me a believer. Thanks also to Old Gregg for reminding me of the oven treatment Shutterfinger suggested earlier in this thread. I had completely forgotten about that.

 

[nbagno]

I have multiple Mamiya RZ lenses with haze. I just order some tools to take them apart and hopefully I can just clean by wiping, not heating :-D

 

[shutterfinger]

 

[Dave Krueger]

The pair of glued elements from the front group of the 127mm lens cleared after a single heat cycle. Not sure why it would be any different, although this lens pair was never boiled. Maybe the haze just wasn't quite as bad or the oven temp was a little hotter. I didn't pay as much attention to the oven temp because I just assumed it would be about the same as yesterday. I probably won't even bother with additional heat cycles for this one.

Attached pictures: The first two are just to show what this pair looks like. I did not attempt to separate the glass from the threaded metal collar, so the first picture is how it was oriented in the pan in the oven. Following that are two pairs of "before and after pictures". The lighting on the pictures is meant to highlight the fog. These pictures don't convey how clear the lenses look when you're just looking through them with the naked eye. This process really seems to turn back the clock a couple decades on these elements. It's what you should and would expect to see on a new lens.

I am so glad I came back to follow up on this thread.

 

[Dave Krueger]

I have multiple Mamiya RZ lenses with haze. I just order some tools to take them apart and hopefully I can just clean by wiping, not heating :-D

From what I gather, haze between cemented elements on Mamiya lenses is pretty common, but the RZ is newer than the RB, so maybe you'll luck out. Heating actually turned out to be much simpler than I thought. For cleaning accessible inner lens surfaces, I found the Lens Pen to be very useful for cleaning without leaving any smears or other cleaning artifacts. It seems better to me than micro fiber cloths. Good luck. Feel free to post how it works out. I'd like to hear about it.

 

[shutterfinger]

Now we would like to see some images made with this heat treated lens.

 

[flavio81]

This is very important news!!

 

[Dave Krueger]

Now we would like to see some images made with this heat treated lens.

Haha! Me too, but I'm not sure how quick that will happen. Most of my photo activities have been on hold for the last several months and I still have 7 rolls of 35mm film to print from a late 2019 photo expedition to Italy. I also have two other cameras that are waiting their turn to go on their first local photo expedition. For now, I will probably just shoot a test roll to make sure everything works okay and that the lens is as sharp as it used to be (ie: that I didn't screw it up taking it apart).