Cleaning HAZE in Mamiya 80mm F1.9 N cemented rear element

[Qiuhong]

Does anybody know who can, or how to seperate the cemented rear element of this Mamiya 80 1.9 N lens in order to clean the haze? the haze is on the glass piece that's second to rear-est. Please help... I called all the repair shops in NYC and none can work on this.

 

[ags2mikon]

Maybe S K Grimes. They used to do lens repairs like re-cementing lens groups. I have had them make retaining rings in the past and was quite happy with them.

 

[Qiuhong]

Maybe S K Grimes. They used to do lens repairs like re-cementing lens groups. I have had them make retaining rings in the past and was quite happy with them.

Thank you, just emailed them

 

[ags2mikon]

Please post back their reply for the rest of us if you would. Thank you.

 

[gone]

Has the op used the lens? The haze may not affect their photos. This can be an expensive repair, and there may be a long wait time to get the repair done. I've been there several times with this problem.

I would sell the lens and buy another one that was clean, but not before seeing how the lens they have now actually performs.

 

[Qiuhong]

Has the op used the lens? The haze may not affect their photos. This can be an expensive repair, and there may be a long wait time to get the repair done. I've been there several times with this problem.

I would sell the lens and buy another one that was clean, but not before seeing how the lens they have now actually performs.

I took one photo with it with a flash on, it had a lot of blooming like a 1/1 pro mist filter, haven't tried it in natural light probably a lot of blooming too..

 

[itsdoable]

Are you sure that is in the cemented elements? That rear optical block has 4 elements in 3 groups.

 

[NB23]

Haze can’t really take plsce between cemented elements. And this doesn’t look like delamination. Looks like an easy job to me.

 

[OAPOli]

I had a problem with cement degradation on a 80mm f/4 macro lens (M645). It wasn't delamination where the elements become separated with a rainbow interference pattern. Looked exactly like haze. It might be caused by solvent bubbling in the Canadian balsam during cure?

Edit: I ended up returning the lens. In your case you could double-check by removing the elements. The lens is a bit more complex than the 80mm f/4.

 

[NB23]

I had a problem with cement degradation on a 80mm f/4 macro lens (M645). It wasn't delamination where the elements become separated with a rainbow interference pattern. Looked exactly like haze. It might be caused by solvent bubbling in the Canadian balsam during cure?

Edit: I ended up returning the lens. In your case you could double-check by removing the elements. The lens is a bit more complex than the 80mm f/4.

Yes but please note the RAINBOW qualification.

Delamination is characterized by a rainbow. Looks like haze, but it’s delamination. You can’t clean the rainbow, needs to be glued.

Haze can be cleaned and it never between elements. Between elements is delamination.

 

[OAPOli]

Yes but please note the RAINBOW qualification.

Delamination is characterized by a rainbow. Looks like haze, but it’s delamination. You can’t clean the rainbow, needs to be glued.

Haze can be cleaned and it never between elements. Between elements is delamination.

I agree you can't clean delamination. But you can have poor cement between glued element. Saw it on the Mamiya 80mm f/4. Appears like haze but can't be wiped off.

 

[removedacct1]

"Haze" is the term commonly used for the deposition of volatile oils (usually from grease in the helical) on one of the air-spaces surfaces. However, if the camera is stored in cold/damp conditions for many years, the cement used to glue elements together can become cloudy, and appear similar in effect to oil haze on an air-spaced surface. It would be worthwhile to first determine which surface(s) the cloudiness is on, but to do that you will need to do some disassembly. Not everyone is willing to go that far to diagnose the problem.

As "itsdoable" stated: "That rear optical block has 4 elements in 3 groups." and so its entirely possible the haze is on one or more of the air-spaced elements.

 

[lxdude]

I called all the repair shops in NYC and none can work on this.

Remembering Marty Forscher, I never thought I would ever see this.

 

[itsdoable]

Haze can’t really take plsce between cemented elements. And this doesn’t look like delamination. Looks like an easy job to me.

You can get fungus growth in a balsam cemented doublets that results in a haze, not the result of oil or desgassing that deposits on a free surface. I've have separated and cleaned cemented doublets. Rainbow delamination is a different thing.

The 1st thing to do is dismantle the optical block, and clean the elements, if the cemented doublet is hazy, that will be obviuos. Maybe the OP is really asking how do you dismantle the optical block....

 

[Qiuhong]

I'm a bit confused by the comments as I'm not that knowledgeable in this area, one guy says it's an "easy job" without explaining what the job is hahah.
The first photo shows the rear group taken out from the lens, the group has 2 pieces of glass held by a black metal tube, and it's hollow in side, the haze (whatever it is) is on the inside of the top glass shown in the first photo. clearing the exterior with alcohol didn't help.

I'll attach a sketch showing where is "haze" is..

 

[Mamiya_Repair]

This is very common on the f/1.9 80mm lens, I see many of them with this issue. The damage is between the cemented doublet and can't be cleaned off.

 

[Nodda Duma]

Haze can’t really take plsce between cemented elements. And this doesn’t look like delamination. Looks like an easy job to me.

Haze can definitely occur in the cemented bond — even if not balsam — if not properly used at the factory. I’ve repaired quite a few doublets from the 60s/70s era which had hazy cement.

 

[NB23]

Yes, obviously, when cement goes bad it also comes with its own haze, debris and gasses.

But in the huge percentage of cases, haze is not inside the cemented surfaces. Well, according to all the people that work with lenses, including you I’m sure. But maybe not in your case, who knows.

But then again, haze in between glued elements is delamination. No other way to put it, really.

Haze can definitely occur in the cemented bond — even if not balsam — if not properly used at the factory. I’ve repaired quite a few doublets from the 60s/70s era which had hazy cement.

 

[Huss]

This is very common on the f/1.9 80mm lens, I see many of them with this issue. The damage is between the cemented doublet and can't be cleaned off.

Exactly what happened to my 80mm 1.9. Became a soft focus lens.. No-one could/would work on it as between cemented elements.

 

[NB23]

It is not a matter of “cleaning it off”, it is decementing.

You can unglue the elements and reglue it yourself. Not very hard actually.

 

[Huss]

You can unglue the elements and reglue it yourself. Not very hard actually.

How do you do that?

 

[NB23]

separate both lenses, clean them. Then, glue them together with a tiny drop of cement right in the center (canada balsam or any lens glue) and squeeze both elements together. The glue will spread and cover completely.
Cure with UV or with time, depending on which glue you have used.

Be as accurate as possible, centering both lenses. It’s not difficult.

 

[Huss]

separate both lenses, clean them. Then, glue them together with a tiny drop of cement right in the center (canada balsam or any lens glue) and squeeze both elements together. The glue will spread and cover completely.
Cure with UV or with time, depending on which glue you have used.

Be as accurate as possible, centering both lenses. It’s not difficult.

Ok, I guess the question is how do you separate the glued lenses. What tools so nothing gets damaged? And then how do you clean the old glue off the previously cemented pieces? A solvent? What kind? Would any mechanical cleaning be involved?
Curious because I sold that lens fully disclosed as being hazed (whatever you want to call it, looking at it, it was hazed) and so suitable for soft contrast shots. It could have been interesting to take a crack at it. But also it was interesting that no repair shop I contacted wanted to touch it. Which, according to your instructions, seems odd if it was as simple as you make it out to be.

 

[jimgalli]

Get a better lens and move on.

 

[lxdude]

Ok, I guess the question is how do you separate the glued lenses. What tools so nothing gets damaged? And then how do you clean the old glue off the previously cemented pieces? A solvent? What kind? Would any mechanical cleaning be involved?
Curious because I sold that lens fully disclosed as being hazed (whatever you want to call it, looking at it, it was hazed) and so suitable for soft contrast shots. It could have been interesting to take a crack at it. But also it was interesting that no repair shop I contacted wanted to touch it. Which, according to your instructions, seems odd if it was as simple as you make it out to be.

There's a lot of info out there on that there internet. At least some of it is good.