doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Another optics thread

The binocular thread got me thinking. Besides, a binocular is a double, right?

I have here a USA M-13 model that followed my dad home from the charming island of Okinawa. I remember it well from my youth. It has seen hard service, although cosmetically it isn't bad. The name of the former owner (who's effects were distributed to those who knew him well) is scratched into the body of the unit.

It's been dropped. One of the adjustable eye pieces is a little funky in operation. It needs collimation.

Anyone have positive experience with any of the optics restorers?

I might have it overhauled for a reasonable price...

Cory Suddharth.....

2nd Cory Suddarth. He has restored several older optics for me. Last was a Bureau of Ships 16 X QM telescope. Went to him rough came back looking new, going to pack up a Unertl 100 MmTeam spotter for Cory to refurbish next. He,s the best in my opinion. Good piece on the internet with the history of your glass. Past army models and how they came up with the WW 2 version. Who made them contract prices etc. If I can find the link will post it

Boats

My Dad was a volunteer in the '50s, in the Ground Observer Corps of the Civil Air Patrol. Anybody remember them? Anyway, he was sent a wonderful, really big binocular, to be used for the identification of aircraft flying over. He also was given a book of aircraft silhouettes and profiles, to aid in identifying potential enemy aircraft.

Does anybody know what those binoculars were?

SRH

Saw that little history piece.

Mine say Nash-Kelvinator 1944.

$72 in 1943 so says the article.

That's over $1k today.

I've read sub yarns that indicate one of the very many things the US was short of for WW2 was optics. Most of the 7x50's that went to sea early on were donated by civilians.

When I did some online research to see about collimating a set of porro prism Sans & Streiffe 7x35's that I dropped out of a tree stand, Cory Suddarth's name repeatedly came up as one of the best in the optics repair business.

You mentioned the possibility of repairing yours if you could get it done at a reasonable price. I kept reading that collimation by a pro was a pretty expensive process, but never saw what it actually costs. I'd be interested in knowing. Anyway, I knew that the old, but nice pair I dropped weren't especially valuable, even if their optics were brighter and more crisp than a set of highly rated Nikons I bought, and subsequently returned. But I did find numerous articles on doing it yourself, which you might wish to try if the cost of repairs is going to exceed the value of the binoculars. Most of the articles you find online deal only with the cheap and dirty method of adjusting the prism adjustment screws, and in some cases, that is perfectly adequate. But here's a couple that go into much more detail on the more in depth methods that align the lenses and prisms, and leave you with perfectly round exit pupils. I haven't made the time to try it myself yet because I have several other pairs of binoculars to use. But it sounds doable, and probably isn't going to hurt to try to make an older or less valuable set functional again.

https://sites.google.com/site/rchamon/home/sun-images-method-for-collimation-of-binoculars

https://www.cloudynights.com/articles/cat/articles/how-to/%E2%80%9Ccollimating%E2%80%9D-binoculars-r408

Thanks for the link, keith.

I'll try to get a rough estimate from that guy.

Thanks. I couldn't get the other link to work, so you'll have to copy and paste it into your browser. There are plenty of other articles online, and even YouTube Videos, but these two seemed pretty informative.

My opinion. Lens coatings on new glass helps reduce flare in bright light. Mechanical parts of new glasses are stronger and the binocular is more likely to stay aligned.

Old glass from top makers like B&L is very good the equal of most modern. Designs were more limited and almost always were right for the purpose. Lot of new stuff is made to sell not work well. About anything you do to change balance will degrade resolution. As power goes up objective needs to be proportional. I have found my vintage optics work well, I am careful how I handle them and don�t expect performance in bright adverse light.

Boats

Thanks. You have a set? That is cool!

SRH