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Questions about my new Vintage Bino acquisition (IF, Diopter markings) (1 Viewer)

sergep71

New member
United States
This is my first post in Birdforum, so hello!

My recently purchased Nippon Kogaku (Nikon) Novar 7x50s arrived in the mail yesterday. I have a pair of 7x35 Mikrons arriving hopefully next week

When I pulled them out of their case, the right ocular was badly loose, like it was in place but wouldn't focus. A quick check unscrewing the eyepiece plastic revealed the set screws, and with a little bit of examination and testing I was able to get them to match fairly close at minimum distance focus. Left ocular was fine.

It was thankfully fungus free, and I was surprised at how eye-popping sharp and bright the image was when both sides matched up in focus well. Eye relief seemed adequate (with the plastic eyepieces) with wearing glasses despite the tiny ocular lenses. It took a little getting used to holding the 'nocs in a way that I could focus with both hands. And at 1 kilo they're not light...

My question is twofold...

How do I ensure both sides are correctly set for minimum/maximum focus? When I set the focus to the opposite end and try to focus on clouds, the pictures are blurry. It seems like I can focus clearly down to around 20 feet/6-7 yards as a rough estimate.

There are diopter markings on both sides - how do I know if this is a factor in how they focus (or, how are the diopter settings supposed to work?) Is this why it's blurry when "set" to infinity?

I was able to obtain the excel file via wayback machine that Hans Braakhuis maintained up to around 2015, and I was able to pin down this is a 1950 model, but is there any way to know/test minimum focus or eye relief just to know the number?

Any insights are greatly appreciated!

~S
 

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If you have 20/20 vision- you need to focus at infinity on both sides, against a bright star- check to see they also have a pinpoint view on the dimmer stars. If you have glasses, wear the latest prescription glasses to do the deed. I often do the same deed with one eye on both sides (the dominant eye). At that point check the side that has the eyepiece collar with the 3 setscrews still locked in place and see if it registers on the "0" setting. Since the collar on the other side is loose, all you have to do is carefully without disturbing the eyepiece by moving it, you should be able to slip the collar in place , install the 3 setscrews trying to drive them in place with the same # of turns on each setscrew (to center the collar on the eyepiece) with the "0" mark aligned with the short line or dot on the fixed eyepiece tube that screw into the binocular frame at the rear. I noticed that the right tube when viewed from the underside doesn't appear to have the white line. If that line is in another position with relation to the body (the left side looks OK), it means that tube isn't completely screwed in (they are a threaded fitting- typically screwed in clockwise) or seated wrongly. Least that's the way I do it Good luck, Pat
 
Welcome.

There are markings on both eyepieces because the instrument is individual focus. Each eyepiece focuses independently of the other.

Presumably when each one is set to zero, the glass is focused on infinity, but I wouldn't bet more then a nickel on that.

The markings help if you want to go (more or less) back to a particular focus setting, without having to look through the glass.

There is no diopter adjustment, because any difference between your eyes is irrelevant, and compensated for as each side is focused for its eye.
 
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