8 replies to this topic

[Vincent33]

Hi here it is the copy of the instructions for this small binoculars.

Saluti.

 

 

Attached Files

•  Istruzioni binocolo russo 4x20 02 FORMATO a5.pdf   217.52KB   372 downloads

[planetmalc]

For the benefit of those who don't know, the Russian 4 x 20 is a reverse Porro design that's similar to the Leitz 4 x 20 'Bitur'.

[Vincent33]

similar to the Leitz 4 x 20 'Bitur'.

No, it's the copy of the Carl Zeiss Turolem,

http://www.fernglas-...urolem_4x20.htm .

I've made a copy from a low resolution jpg, but the pdf I've posted is a word-by-word duplicate, even if it's not aestetically equal. This instruction manual can't be found anywhere than here.

Bye.

[Clive Aintree]

Yes indeed, a copy of the Zeiss Turolem, one of which I have in my mostly Zeiss binocular collection. Here's an oddity - the screw which retains the focussing helical thread and the eyepices which are attached to it (exposed by removing the central cover at the front between the objectives) has a a left hand thread. Wonder whether the Russians copied that too?

[Vincent33]

Yes indeed, a copy of the Zeiss Turolem, one of which I have in my mostly Zeiss binocular collection. Here's an oddity - the screw which retains the focussing helical thread and the eyepices which are attached to it (exposed by removing the central cover at the front between the objectives) has a a left hand thread. Wonder whether the Russians copied that too?

Sorry I am not able to make this check. I dare to make anything like this ...

They are marvellous tiny little binoculars, nothing in the market today like these. Bye and sorry again ....................

[Vincent33]

The Russian 4 x 20 is a reverse Porro design that's similar to the Leitz 4 x 20 'Bitur'.

It is not a reverse Porro. It's a classic Porro design, but the hub (or could it better defined the "pivot"?) isn't placed at the usual place, between the oculars, but in a "half way". I don't think I've expressed myself correctly, sorry.  :-)

[planetmalc]

 

The Russian 4 x 20 is a reverse Porro design that's similar to the Leitz 4 x 20 'Bitur'.

It is not a reverse Porro. It's a classic Porro design, but the hub (or could it better defined the "pivot"?) isn't placed at the usual place, between the oculars, but in a "half way". I don't think I've expressed myself correctly, sorry.  :-)

 

 

So what's your definition of 'Reverse Porro'?

[Vincent33]

 

 

The Russian 4 x 20 is a reverse Porro design that's similar to the Leitz 4 x 20 'Bitur'.

It is not a reverse Porro. It's a classic Porro design, but the hub (or could it better defined the "pivot"?) isn't placed at the usual place, between the oculars, but in a "half way". I don't think I've expressed myself correctly, sorry.  :-)

 

 

So what's your definition of 'Reverse Porro'?

For me a "reverse Porro" is a binoculars that has a pivot between the objectives to arrange the interpupillary distance, like on http://www.optics4bi.../basics1.aspx .

See figures 3# and 4#.

I *think* the Zeiss Turolem and the Russian 4x20 are common Porros, just with the "pivot" put halfway the objectives and the oculars. But maybe I'm wrong. You made me in trouble!  :-)

[planetmalc]

 

 

 

The Russian 4 x 20 is a reverse Porro design that's similar to the Leitz 4 x 20 'Bitur'.

It is not a reverse Porro. It's a classic Porro design, but the hub (or could it better defined the "pivot"?) isn't placed at the usual place, between the oculars, but in a "half way". I don't think I've expressed myself correctly, sorry.  :-)

 

 

So what's your definition of 'Reverse Porro'?

For me a "reverse Porro" is a binoculars that has a pivot between the objectives to arrange the interpupillary distance, like on http://www.optics4bi.../basics1.aspx .

See figures 3# and 4#.

I *think* the Zeiss Turolem and the Russian 4x20 are common Porros, just with the "pivot" put halfway the objectives and the oculars. But maybe I'm wrong. You made me in trouble!  :-)

 

I use the term 'Reverse Porro' if the centres of the objectives are closer together than the user's IPD when being used.     My Leitz Bitur 4 x 20 is certainly like that, and I've seen photos of the Russian 4 x 20 currently on the 'net that suggest that it is similar.