Leica Stereozoom 6: dirty lens

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cmug
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Leica Stereozoom 6: dirty lens

#1 Post by cmug » Mon Mar 30, 2020 2:20 pm

I was cleaning up at work (Middle school) today. And at my surprise I found three nice old binocular microscopes at the bottom of a cabinet. Well with some backward maintenance.
I start the repair of the first one now. It is a Leica Stereozoom 6. Mechanically this is fine if I put new grease in it (and removed the old one first).
What I no longer get right is the last lens surface, there is a kind of fog on it. See the pictures. I have tried various solvents. No effect. Is this lens still to get clear?
Or should I learn to live with it. Even with a damaged lens, the image is still remarkably good

Image Image Image

Scarodactyl
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Re: Leica Stereozoom 6: dirty lens

#2 Post by Scarodactyl » Mon Mar 30, 2020 2:38 pm

Perhaps permanent mold damage? A bummer but if it still works it could be worse.

cmug
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Joined: Mon Oct 29, 2018 8:36 pm

Re: Leica Stereozoom 6: dirty lens

#3 Post by cmug » Mon Mar 30, 2020 6:58 pm

The Leica Stereozoom 6 was the binocular was the one with the damaged lenses.
I also found same binocular with name Bausch & Lomb (exactly the same) ; these lenses where nearly perfect clean.
I compare these 2. In sharpness there is not a big difference.
The Leica has less contrast, slightly more affected by light flare. And remarkable the black are not black, the blacks are more greenish.

Scarodactyl
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Re: Leica Stereozoom 6: dirty lens

#4 Post by Scarodactyl » Mon Mar 30, 2020 9:13 pm

Looking closer (now that I'm on my desktop) the SZ6 does alas look to have permanent mold damage. It happens, not much to be done about it.

The compound head looks delaminated. Bausch and Lomb sold Olympus scopes (as the "Galen I") Kyowa scopes (as the "Galen II") and Chinese scopes (As the "Galen III", which I think was a Chinese copy of the Olympus BH2) so it could be any of those, which were also sold under other names. It would be worth taking a photo of the whole system to know which one you're dealing with.

cmug
Posts: 13
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Re: Leica Stereozoom 6: dirty lens

#5 Post by cmug » Fri Apr 10, 2020 5:17 pm


deBult
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Re: Leica Stereozoom 6: dirty lens

#6 Post by deBult » Fri Apr 10, 2020 5:56 pm

Before you do: may seem strange but first give it another try using demi-water plus a drop of fairy dish wash liquid.
It cleaned way beter than the usual candidates and saved 2 of my stereo-zooms.

It did Not help on a fogged Reichert lens: lightly polishing with a mix of demi-water and cerium oxide on a old towel around a fingertip did the trick.

Good luck, deBult

dtsh
Posts: 67
Joined: Wed May 01, 2019 6:06 pm

Re: Leica Stereozoom 6: dirty lens

#7 Post by dtsh » Fri Apr 10, 2020 8:17 pm

cmug wrote:
Fri Apr 10, 2020 5:17 pm
Found this
https://www.instructables.com/id/Glass- ... al-Lenses/
Doubt may be I try
As someone who's ground a little glass, if you try this it is very important to vary the motions a little so as not to introduce zones; imagine motions similar to the precession of the pole on the planet. I would advise you to not use a rotary tool, instead preferring to do it by hand. The amount of time it should take to repolish the surface should be very little, maybe 15 minutes as you aren't trying to change the figure of the lens, just polishing the surface. Make absolutely certain the surfaces are clean, a tiny grain of grit between the glass and tool can easily score the lens and make matters worse. Clean and rinse carefully!

Hobbyst46
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Re: Leica Stereozoom 6: dirty lens

#8 Post by Hobbyst46 » Fri Apr 10, 2020 8:24 pm

Scarodactyl wrote:
Mon Mar 30, 2020 9:13 pm
Looking closer (now that I'm on my desktop) the SZ6 does alas look to have permanent mold damage. It happens, not much to be done about it.

The compound head looks delaminated. Bausch and Lomb sold Olympus scopes (as the "Galen I") Kyowa scopes (as the "Galen II") and Chinese scopes (As the "Galen III", which I think was a Chinese copy of the Olympus BH2) so it could be any of those, which were also sold under other names. It would be worth taking a photo of the whole system to know which one you're dealing with.
The one Galen III I have seen is smaller than the BH2 and not really a match in terms of quality or exapandability. It was made by Cambridge Instruments in China AFAIK.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

Scarodactyl
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Re: Leica Stereozoom 6: dirty lens

#9 Post by Scarodactyl » Fri Apr 10, 2020 11:35 pm

Copy in a broad sense (I have heard the heads are compativle for instance) but apparently not an exact clone.

cmug
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Joined: Mon Oct 29, 2018 8:36 pm

Re: Leica Stereozoom 6: dirty lens

#10 Post by cmug » Mon Apr 20, 2020 2:29 pm

I bought Cerium-oxide. Circa 0,5-1,0 micron. And did the experiment. Make a paste from the Cerium-oxide and distilled water. Used an Dremel polish + PEC pad at top. And polish for ~ 20 minutes. After the polish The glas was much better, still not as new.
Unfortunately, it was only possible to process the lens on one side.
Visually, the lens is now better.
But. . . Looking through the bi-ocular, the image has become slightly worse. So conclusion: experiment failed.

deBult
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Re: Leica Stereozoom 6: dirty lens

#11 Post by deBult » Mon Apr 20, 2020 5:03 pm

Sorry to hear the polishing did not work out.

Ehh: As stated: I polished lightly with a fingertip in an old towel ..
Using a Dremel for 20 minutes probably changed the lens curvature??

dtsh
Posts: 67
Joined: Wed May 01, 2019 6:06 pm

Re: Leica Stereozoom 6: dirty lens

#12 Post by dtsh » Tue Apr 21, 2020 12:40 am

deBult wrote:
Mon Apr 20, 2020 5:03 pm
Using a Dremel for 20 minutes probably changed the lens curvature??
Hard to tell, but probably not if the polishing wheel is soft enough. I'm used to using pitch for the polishing lap, but I am aware some people have used felt pads to good effect. Were it me, I'd heat up some pitch and give the lens a couple passes, but I realize most people (the sane ones at least) don't have pitch just hanging around.

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