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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Observations inside two Abbe Koenig Zeiss models (1 Viewer)

613Orm

Well-known member
Hello!

I am the very happy owner of one pair of 10x42 Victory FL and one pair of 7x42 Dialyt T*P*.
However, one day I decided to look down the tubes of my FL from the objective side. First I was shining a strong LED lamp in through the front lens, and it looked as nice and clean as one should expect. Then I took the lamp (the LED flash on a regular smartphone) and shone it in through the ocular while I was still looking down through the front lens of the same tube. Interestingly, this gave the possibility of observing more about how the prisms etc are attached to the body. Then, when playing a little with the angle of the light, I noticed how the surface of a prism showed a strange surface texture. It had a rough surface of the coating with a transition into a cloudy appearance. It created a kind of halo that seemed to originate from a blob of glue just between the edge of the prism and the wall of the tube. The same, but much smaller, could be seen in the other tube at the same location. In the first tube the rough textured/cloudy halo covered about 20% of the prism surface on that side.
I took my Dialyt and made the same check. It also shows a similar surface feature of the prisms in the same location, also seemingly originating from what appears to be a drop of glue. [It certainly looks like what one could expect around a drop of super-glue, which often tend to cause fumes when solidifying]

Has anyone else seen this in any binocular of similar construction (Abbe-Koenig)?
If so..
Does it have any effect on the fuction, or does the light pass the prism/get reflected through/on other surfaces? [I think the image through both my binoculars is perfectly clear, but everything is relative...]
Are the prisms in Zeiss A-K binoculars attached with glue?

I think there is maybe 10-15yrs between my Dialyt and the FL. I live in a very dry climate, and it does not look like fungy. It rather looks like fumes from glue, and some disruption of the prism coating most proximal to the potential glue drop.

Kind regards
orm
 
I'm sure someone will be along to shed light but I fear no matter the pronouncement you will henceforth always be thinking about that discovery and when you should be focusing on enjoying the observational moment . Well at least that's how it would impact this twitcher but I am mildly OCD.

I will refrain from the same experiment with my Night Owls just in case!

LGM
 
Well. I hope maybe someone knows the answers to my questions. I am very curious what this thing is, if it is a common feature, and if it has any effect on the function. If it is standard procedure to mount the prisms with glue I wonder why chosing a glue that cause such fumes.
 
I have added a photo. Zoom in and you'll see what I mean.https://drive.google.com/folderview?id=0B62pqSzAjbtzSTVnNkV6T0Jjb00

I know you will not be happy for this report. Using your photo, I made careful inspection of my Zeiss 7x42 BGATP from 1995 or 1996, and found the equivalent view that you show. Mine does not contain your putative "blob of glue" or its hazy extension. Instead, the glass is essentially clean to the edges in that location, and elsewhere.

--AP
 
Have you noticed whether or not the appearance of this strange substance on the prism affects the view through the binocular?

Bob
 
The photo is from my Victory FL, but something similar, but smaller, is visible also in the 7x42 Dialyt.
I have not noticed that the image is affected, but any subtle differences may be hard to tell (How can I tell?). The damage, or whatever it is, is bigger in one tube than the other, but I notice no difference in image between them.
Maybe it is on a surface that has no effect on how the light passes through the prisms. But I could immagine that it is not good to have disturbances like this on the surfaces in case they are either penetrated by the light or reflect light inside the prism. But maybe this is on a side of the prism where it does not matter. Can someone tell from my photo?

I am not unhappy that others do not see the same problem, on the contrary!. I think my Dialyt is also from about 1995 (It's a T*P* but was still not called "Classic") and I think I bought it at around that time. My Victory FL is from around 2008. That one I bought second hand a couple of years ago. As it certainly is not possible for myself to place those blobs of possible glue at these locations inside the binoculars, and that they appear in two different binoculars, is an indication to me that it must be something in the production process. Maybe Alexis' binoculars have an undetectable amount of glue (possibly as it should be if glue is used) and I have had bad luck with both my specimens at two separate occasions and models.
As the binoculars are pretty old I can only hope that the potential glue has finished giving off vapors, and that the current damage is not affecting the view. Is it some way to tell?
I may be picky, and look to deep into the glass (ha ha), but when buying these glasses I have spent basically all net savings I had and feel that I can expect perfection. I think alfa glasses (even though old alfas) should hold for an inspection like this.

So, basically, I am just interested in 1) if someone knows what it is, and 2) if someone knows if such things affect the view or if that glued side of the prism does not participate in the light transmission path. [In a porro binocular I have there are parts that are attached with something like white chewing gum, even covering parts of the surfaces. I have seen it in many porros of various prices. Obviously, it is considered not to affect the light path. Maybe it is the same for the A-K prisms]
 
I may be picky, and look to deep into the glass (ha ha), but when buying these glasses I have spent basically all net savings I had and feel that I can expect perfection. I think alfa glasses (even though old alfas) should hold for an inspection like this.

I cannot agree with this amigo. The amount you spend, and how much it means to you, does not mean you will necessarily get perfection, especially if you demand this extends to every aspect of production and finishing. What I want to ask you is... how happy are you with the view that you get through your two binoculars?
 
Quite happy.
Possibly even happier if I knew the stuff on the prisms had no effect. [I repeat my hope that someone may know if such coverages of the prism surfaces have any effect]

I think a 20% coverage of a prism surface with some stuff from a vaporizing glue is not really what I would expect in an alfa binocular even without having too high demands on perfection. My kids have PRC made binoculars that look cleaner inside. Certainly, the view through my Victory FL is better than those. But is it the same as another Victory FL? Do they all have this stuff on the prism surfaces? Obviously not all Dialyts have it.
Maybe two times bad luck?
 
Let's see it like this; 1) I had bought a cheap car and it had some bad paint job making the paint all bubbly on a fender. OK, I'd be a bit disappointed and drive on. 2) I had bought an expensive car and it had the same bad paint job... Some people would go through the ceiling. In my case I have merely got worried, disappointed OK, but accepted it with a question if it at all affects the function of the car. How can I know? I am no car expert. Maybe someone says that a bubbly paint will make the paint fall off. Tough to accept for an expensive car. Or maybe they say it has nothing more than a cosmetic effect. Sad on an expensive car, but more acceptable.

Well, I have dwelled enough on the emotional side of this. I was just hoping for some more technical answers. Indeed, I'd find it quite interesting if my two binoculars are the only specimens that show this.
 
I really don't think you have anything to worry about. If you look at the Wikipedia for AK prisms you only need the entry and exit prism faces to be clean and perfect. It's hard to see what your picture shows but that amount of glue/spreading would surely be visible if it was one of the light path entry/exit prism faces.

Having taken a few binos and scopes apart you find some prism exterior parts roughly finished as these do not form part of the light path, at least that is what I surmise.
 
I have added more photos to the folder link given above. Some are marked FL and some Dialyt. As you can see the Dialyt is mainly just some cloudy spot whereas in the FL it is some kind of texture on the prism surface.
 
Thank you Dipped!
It would make sense that the glue is on some side of the prism that is not for the light path. But all the rest of the surface looks soo perfectly polished so I thought it was an active prism surface.
Not sure if my other photos are to any more help. It is difficult to take photos of the feature. The light must be right.
I like looking through binoculars, but I also like to look into them, as you have noticed...
 
I really don't think you have anything to worry about. If you look at the Wikipedia for AK prisms you only need the entry and exit prism faces to be clean and perfect. It's hard to see what your picture shows but that amount of glue/spreading would surely be visible if it was one of the light path entry/exit prism faces.

It looks like a side-face to me and so not in the light path. I agree with you Dipped.

Lee
 
Good to hear this from you guys that know the constructions of these types of binoculars. I had been looking at various drawings of the interior of Victory FL and other A-K binoculars, but I could never figure out where in those drawings my observed feature was located. I was also worried that maybe not only the entry and exit surfaces had to be perfectly clean, but somehow also other surfaces where light might get reflected from the inside (But maybe those internal reflections do not need coated prism surfaces).
I feel more relieved now. Certainly, as said, I have not noticed any obvious strange effects on the views through the binoculars (e.g., fuzzy sectors, increased vailing reflections, or whatever one could expect). It was just this gnawing feeling that maybe, maybe there is some effect that I would only detect if side-by-side comparison.
But I can't help wondering how wise it is to use a glue that gives off such vapors inside an optical instrument. Maybe not a problem, but to me it feels a bit of a gamble.
 
But I can't help wondering how wise it is to use a glue that gives off such vapors inside an optical instrument. Maybe not a problem, but to me it feels a bit of a gamble.

Something is a gamble when you do not already know the result. I suggest that Zeiss knew what they were doing when they secured the prism in this way.

I might be wrong but I think it is possible the glue attaches the prism to a 'cage' and the cage containing the prisms would be inserted into the optical tube and attached in a different way. If this is correct the gases from the glue would have escaped outside the bino.

Lee
 
So I did the same. I didn't find glue globs. I did see on one prism a very slight cloud on one edge��. Now I can't sleep.
 
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