From: "William M. Beacom" <bbeacom@___.net>
There is no doubt in my mind B&L made this binocular for the U.S. Navy using an EE body design but casting the hinge and strap lugs to accomodate the larger 50mm lense. The early B&L 10X45 a copy of the Terlux was almost impossible to seal, and the Navy urgently needed a higher power Binocular in WW-l. This is not a made up Binocular unless an amateur would have the casting and machining facilities of a Factory. The only part that is a mystery is why they made them Center Focus. My guess is, they only became available toward the end of the war so they sold on the civilian mkt like the Mark-41 without ever being catalogued. I currently own three, all civilian marked but one also has Navy markings. Bill
Subject: Russian 20x50, 30x50
From: "Osborn Optical" <optical-repair@___t>
Has anyone had a chance to evaluate the Russian, SIBIR 20x50 or 30x50 "Newtonian Reflector" hand held binoculars? Someone ask me about them the other day, and I haven't yet had my hand on a pair, or heard from anyone that has.
These are named rather inappropriately (not being Newtonian reflectors), and are suspiciously high power, but with Russian glass, quality can come in odd packages.
SIBIR 20x50 30x50 Newtonian Reflector
Subject: U.S. availability of binocular book
From: "Mike" <mike@___heoptik.com>
New book just in: Gregory, R.C. Notes on Binoculars and Their Use, 2003, Amwell Books (UK), 118 pgs, an interesting summary of Robert Gregory's many years of binocular collecting, not all-inclusive but much good information and valuable opinions, includes a number of b/w photos, binocular specifications for various British, French, and German makers, and a useful bibliography, soft cover, Price $40
Subject: Kronos 6x30
I recently obtained a Kronos 6x30 extra wide angle binocular and came accross some excellent reviews by Dr. Holger Merlitz, a physicist in Germany. I highly recommend the reviews and plan to do some comparisons with some other 6x30s in the collection. It is a very impressive glass. The folks at ITEAstronomy are great to talk with and have a vast experience in comparative optics. They feel the Kronos glasses are optically equal to most of the high line Japanese-but a bit shy of Zeiss, Leica and the best of Nikon. Their testing suggests equivilance even with Swarovski. I contacted Dr. Merlitz to discuss the mechanics of Russian binocs. I have been told by immigrants who were involved with manufacture in Russia that in order to meet cold weather requirements the mechanics were often machined loose and various optical greases were used to provide the viscosity appropriate to the climate. In actual practice only the least viscous were used because