Leica Trinovid 7x42 BA (1 Viewer)

[chill6x6]

I've never thought about the access to focusing on my 8x32BN until I saw your post, and while I can see your point, all three (older Leitz, BN and Ultravid) that I tried just now seem very easy to focus, with possibly the highest ease (and smoothness) coming from the Leitz.

Since you've got all three as well (albeit in different magnifications), how do you like your oldest one there, which I'm assuming is the 7x35b?

So the 7X35 is ACTUALLY the current model Retrovid. Of course it's a super binocular and it is youngest 7X binocular I have.

I have to consider that BN is the only binocular I have where the focus wheel is arranged as such. AND...I don't use it much at all with the UVHD+ and Retrovid at hand. If I used the BN moreI I'd probably get used to its way of focusing.

 

[SUPPRESSOR]

Get the Leica if it is in good shape, at least it is built to seal out moisture unlike for example the Dialyt.

The chances are after all these years the nitrogen as leaked out so they could and do let in moisture.
Pete.

 

[dries1]

It is amazing the quality on the BAs/BNs which were made at that time. I spoke with an ex rep from Leica and was informed that many they received for service had never been opened since production.

 

[tenex]

The SLC seems to come in third but has an interesting/unique optical design -- search for threads about it here to learn more.

Here's one thing I've wondered that wasn't explained in those threads... If 7x42 SLC wasn't just a different eyepiece stuck onto the 10x model as usual, why couldn't it achieve a larger FOV?

 

[Pinewood]

It is amazing the quality on the BAs/BNs which were made at that time. I spoke with an ex rep from Leica and was informed that many they received for service had never been opened since production.

Hello Andy,

That would seem to mean after 20 or 30 years of service, those binoculars were first sent in for service. Leica binoculars have a well deserved reputation for durability.

Stay safe,
Arthur

 

[John A Roberts]

Hi tenex (post #24),

I too have long been puzzled as to the 7x42 and 10x42 SLC optical details.
What we do know . . .

A) The 7x42 and 10x42 are shown as having the same optical construction:



But, as can be seen from the spec’s in the 2005 catalogue, the 7x42 is listed as 2.8 oz (80 g) heavier.


B) Which is a big difference when compared to the three x50 models, that only vary by 0.3 oz (10g).
And we know from cutaway units that they share the same construction, and vary magnification by changing the size and curves of the eyepiece lenses:



(more on the x50’s can be found in post #6 at: Differences between 2003/2008 SLC binoculars? )


C) And then in between, are the 8x56 and 15x56 models which differ by 1.8 oz (50 g).
The only other detail I have for them is from the 2012 catalogue that states they each have a 3 lens objective.
So I’m inclined to the view that:
• the 8x56 may use the 7x50 eyepiece (note the similar ER and AFOV figures), and;
• the 15x56 will necessarily have more glass in the eyepiece, perhaps with an extra lens, and a different configuration
(and note the greatly reduced ER compared to the 8x56 and x50 models).


- - - -
So with the x42’s, as the 7x42 has significantly greater ER, there’s likely more glass in the EP.
But if the rest of the weight difference is also due to glass, then likely the prisms would also differ (?)
And if so, as you ask, why not a wider FOV?

Alternatively, while the x42 image above may show the initial optical construction as being shared,
could the 7x42's have been significantly redesigned during production?

. . . so questions without answers (we need an emoji of someone scratching their noggin!).


John

 

[tenex]

Thanks, John. The 7x42 was apparently also 17mm longer than the 10x, another unusual difference. And yet the diagram seems to show similar basic construction...?

🤔 ? (curiosity may be less common than one might wish)

 

[John A Roberts]

Another thread just prompted me to look at the obvious . . .

See the eyepieces of two late production SLC’s (from 2009 and 2010 respectively);
the 7x42 from a 2019 eGun listing by Jochen04, and the 10x42 from a 2016 eBay listing by jakedobbins12.

As can be seen the 7x42 has a larger diameter eye lens and presumedly also more glass in the rest of the eyepiece,
as was supposed in the previous post.


John