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Early Leitz Trinovid versions, variations, & arcana (1 Viewer)

Just a side note, both of the 7X42s I posted earlier have the lines also looking through the objectives, on the earlier model the lines are not as pronounced as the later model.

Andy W.
 
Hi,

I agree with Henry that a change of the objective design would indeed explain why the roof edge is in focus when looking in from the objective end in case of the older 8x32 and not with the 8x32B.

It would also make sense to do so since for the B (for Brille aka compatible with glasses) version they had to redesign the EPs and maybe used the opportunity to use a common EP for all sizes which obviously needs a changed objective.

Anybody knows about xray images or detailed drawings of old Trinis?

Joachim
 
From Gijs post 7.
The 10x40 Trinovid here in poor condition has a red circle, so 1977 to 1988.
122m/1000m.

I can see a very faint line centrally looking at a lamp from the objective side.
I'll try further, but can't see a line from the eyepiece end. At least not yet.
 
@henry link #19

Attached see a photo with a small light source reflected in the objectives of a B-type 130m version on the bottom, and a non-B 150m version above. In each case there is a reflection near the bottom, probably coming from the prism, and two reflections, close together, near the top. I believe these are what you were talking about, and I see no significant difference between the two instruments. Do you?

(Sorry for the mediocre quality of the photos I have uploaded, but it is really tricky to catch the reflections or the diagonal line without a lot of special supports, lighting, and time.)
 

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@jring #14

I just did the test, looking through the objective end through polarizing sunglasses, with the ocular pointed at a blank white LCD computer screen.

In both the non-B and the B-type, at a certain position of the polarizer the bottom half of the glass goes dark, with a very sharp line between dark and light. The orientation of the diagonal line dividing light an dark is in the same relative position in both types of binoc, and that dividing line in the non-B is exactly where it appears without the polarizer. The only difference apparent between non-B and B-type is that in the former the line is always visible, but in the latter only when viewing with a polarizer.

Deduce from this as you can!

PS-just to muddy the waters I did the same test with a Swarovski 8x32EL. Here the entire "window" turns dark when the polarizer is in a certain position, but not quite black, rather a dark blue-purple. Of course the Swaro has coatings unknown to the Leitz engineers of the 50s and 60s.
 
@henry link #19

Attached see a photo with a small light source reflected in the objectives of a B-type 130m version on the bottom, and a non-B 150m version above. In each case there is a reflection near the bottom, probably coming from the prism, and two reflections, close together, near the top. I believe these are what you were talking about, and I see no significant difference between the two instruments. Do you?

(Sorry for the mediocre quality of the photos I have uploaded, but it is really tricky to catch the reflections or the diagonal line without a lot of special supports, lighting, and time.)

I can't tell for certain, but the two closely spaced reflections might be coming from the internal surfaces of an air spaced doublet. Could be that the fourth reflection isn't showing at the angle the lenses were photographed.

The photo below shows the classic return pattern from a cemented doublet at the top (Nikon 8x30 E), two glass to air reflections and a single tiny reflection from the cementing between the elements. The bottom set of reflections (Zeiss 8x30B Porro) is typical of an air spaced doublet returning four reflections. The prism glass reflections can be eliminated visually by noting whether a reflection stops at the edge of the prism aperture.

Your test for phase coating had the expected results, non-phase corrected Trinovids and phase corrected EL.

Henry
 

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Re. my post 23.

Looking into the objectives of the 10x40 Trinovid with a 75W bulb about 2ft away I can see the thin line in each barrel when the bulb is just off centre. Each line is rather faint.
By moving the image I see the whole line, but only part of the line in any one position.

I cannot see any lines when looking through the eyepieces.

Usually reflections from prism surfaces show a flat surface, which is seen by moving nearer or further.
Most lens surfaces are curved and show changing image size, although the rear surface of the eyepiece may be flat.
 
Before anyone had actually dated the two Trinovids here, it made sense to me that the diagonal line might indicate that the early bino lacked phase coating while the later one had it, presumably having been made after 1988. I see now that it wasn't. So much for that theory, and glad to be corrected.

I read about it right here on BF not long ago. The relevant test suggested by chartwell99 reads:
"Hold the binocular approximately 14 inches away from your eyes and look through the objective lenses. A roof prism binocular which has not been phase coated will show what appears to be a thin black line diagonally across the image of each lens. This line is not visible when the prisms have been phase coated."
My impression was that other comments confirmed this, although upon reexamination now this seems unclear.

The polarized-glasses test seems to be the right one for phase coating. So why then would so many binos consistently show the diagonal line, including Leitz Trinovids? Damage or QC fails seem implausible.
 
Another rather unlikely possibility for the roof edge being more visible from the front in the early Trinovids just occurred to me. The Uppendahl prism can be installed in two ways. One way is with the roof prism as the last prism closest to eyepiece and the other way is with the roof prism as the front prism closest to the objective lens. Placing the roof at the eyepiece end would seem to be the natural choice, but if its position had been switched from back to front at some point in production that would certainly affect the roof edge's focus and apparent size as seen from the front.
 
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If I understand the attached diagram, focusing is done by moving the Upendahl prism assembly, and the assembly is asymmetrical, with the rear prism thicker than the front one. Perhaps, Henry, as you suggest the assembly is reversed between the non-B and B-type models.

There seems to be limited number of things Leitz could have changed between the non-B and B-type models. The objective tubes measured from the front of the main body to the end of the tubes is identical, I note.
 

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Hi,

thanks for doing the reflection picture and the polarizer test. This is instructive...

From the two reflections I would say that both objective lenses are cemented doublets (singlets or cemented multiplets would be possible too but not probable). But I'm not the specialist here - Henry, what do you say?

The results with the polarizer test are exactly as expected: The two trinivids show the two distinct half circles which proves that the phase shift at the roof edge has taken place and thus the light reflected from one half is polarized one way and goes through the polarizer while the light from the other half has been phase shifted and has a different polarization and is thus blocked by the filter.

In the Swaro EL pair, there is phase coating as there should be and thus no distinct half circles are visible (it's expected to get completely dark if you turn the polarizer far enough).

Regarding Henry's theory of the switched Uppendahl - plausible as always. Tony's drawing shows the Uppendahl in the same direction as in the images of the B on the auction side link I posted ealier, that is roof edge (aka the wider side) to the EP. Is the drawing of the B or non-B?

I'm not sure though, how moving the Uppendahl will enable you to focus... I would say that you have to move the EP or some elements (aka focusing assembly - as is shown here). The normal focuser moves the element in both EPs in unison while the diopter moves only one side.
You can test btw. if your theory of the focuser moving the prism - in the pair wth the roof edge visible, you should be able to get the line out of focus with the focuser if your theory was true...

EDIT: seems I should have read the second page before answering... thanks to Henry for the explanation of the reflection patterns... I would love to learn this art.

Joachim
 
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The 10x40 Trinovid 122m/1000m seems to have air spaced doublet objectives with possibly a steep curve in the rear elements.
It doesn't seem to be as shown in the cutaway drawing in post 30.

I would have to take it apart to actually measure the curves.

Looking again, the rear objective element curve is only moderately steep.
The two facing internal objective surfaces are almost equal, but I don't think this is a contact doublet, rather it has a small air spacing.

At 576g or 20oz this is a handy binocular. Wish this was not in poor condition, as otherwise I would actually use it.
 
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In #30, I believe the diagram is of a B-type, but looking more carefully, I believe it shows clearly that inner elements of the ocular move for focus, not the prism assembly. I was perhaps led to my careless error by the photos of the physical cutaway example of the 8x32 cited earlier by another member. One can see a spring attached to the prism assembly, but perhaps that is the anchor end of the spring, not the active end, which might be the movable lenses.

The diagonal line seen in the non-B model is sharp, no matter what the focus setting.
 
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In #30, I believe the diagram is of a B-type, but looking more carefully, I believe it shows clearly that inner elements of the ocular move for focus, not the prism assembly. I was perhaps led to my careless error by the photos of the physical cutaway example of the 8x32 cited earlier by another member. One can see a spring attached to the prism assembly, but perhaps that is the anchor end of the spring, not the active end, which might be the movable lenses.

The diagonal line seen in the non-B model is sharp, no matter what the focus setting.

Tony
Don't the different shades of orange have significance? And if they do doesn't this suggest that the prism moves for focus and the left-hand ocular moves for dioptre adjustment (note the arrow)? Or am I barking mad as usual?

Lee
 
I believe you are right, Lee. I was not paying sufficient attention to the color scheme. So, the prism assemblies move in both halves of the binoc, and the inner lenses of the ocular of one half move for diopter adjustment.
 
I believe you are right, Lee. I was not paying sufficient attention to the color scheme. So, the prism assemblies move in both halves of the binoc, and the inner lenses of the ocular of one half move for diopter adjustment.

I think you had it right the first time. Only the first three elements of the eyepiece move for focusing. Moving the prism would have no effect on focus. The focusing knob moves the eyepiece lenses in both sides simultaneously, the diopter adjustment knob moves only the left eyepiece lenses.

I looked back at the old brochure I used to post that 7x42 cutaway a few years ago. It must be the last one devoted to the old Trinovids since it's dated August 1989. There was a little more information about the focusing which I posted below along with a better (I think) photo of the cutaway.

Henry
 

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I think you had it right the first time. Only the first three elements of the eyepiece move for focusing. Moving the prism would have no effect on focus. The focusing knob moves the eyepiece lenses in both sides simultaneously, the diopter adjustment knob moves only the left eyepiece lenses.

I looked back at the old brochure I used to post that 7x42 cutaway a few years ago. It must be the last one devoted to the old Trinovids since it's dated August 1989. There was a little more information about the focusing which I posted below along with a better (I think) photo of the cutaway.

Henry

Thanks for this Henry. And isn't it a super illustration? Zeiss used to do similar diagrams but these seem to have fallen out of favour in recent years.

Lee
 
The diagram on the left in Henry's post 36 does show a Trinovid air spaced objective.
But I don't think the curves match the 10x40 122mm/1000m here.

Maybe the narrow field Trinovid has different objectives.

Leitz and others used to slightly alter diagrams, glass formulations and specs to try to prevent copying, but nowadays something like Televue eyepieces are bought as soon as released, dismantled, measured and copied in China without any regard to copyright.

The same happens to ebooks. Immediately on release they are copied and pirated and offered for nothing.
These pirated copies may also infect or seize one's computer, although I am not sure of this.
 
Only the first three elements of the eyepiece move for focusing. Henry

Confirmed: Leitz Trinovid Uppendahl prisms do not move; they are mounted firmly in place. I once owned a cutaway 8x32B and one could easily observe which parts moved for focusing and which did not.

John
 
It appears we have clarified many things in this discussion, but my question from my first message remains: why does the diagonal line appear, seen through the objectives, in the non-B models, but not in the B-type? I questioned whether there was a fundamental design difference between the two types. Now I believe that both types of Leitz Trinovids have Uppendahl prisms, but suspect that not only was the ocular system modified to produce greater eye relief at the cost of less FOV (130m vs 150m in the 8x32), but also something was changed with the prism. But What?
 
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