Avimo prototype binocular 7x42 roof prism and military model (1 Viewer)

[Kevin Purcell]

A very interesting paper on prototype Avimo 7x42 prototype designed for the UK armed forces in the 1970s and in service in 1979 as the Type L12A1.

There are two previous threads on this bin

http://www.birdforum.net/showthread.php?t=140154
http://www.birdforum.net/showthread.php?t=43408

I thought "roof prism" was a typo but it isn't. The original design was a roof and they switch to sort of 45° "over-under" porro for the actual issued design. There is also a similar monocular roof prism prototype.

http://www.binoculars-cinecollectors.com/Avimo_prototype_7x42_and_military_model.pdf

One interesting think that this paper has (and the site does as a whole) is to X-ray bins, and EPs to see their internal design. Very nice.

The scientist, who had written and published an article about porro Avimo, claiming that by setting collimation of the binocular by closed distance; I believe less than four meters, and not collimated on infinity, made the binocular superior and gave mathematical reason for this. Unfortunately no other binoculars’ manufactures have ever come to the same conclusion.

Very odd.

The design was licensed to German Company Rollei. Later on Russian copied the binocular and starting produce by BELOMO in Minsk. BELOMO or Belorusskoe Optiko-Mechanichesckoye Obyedinenie (Belarus Optical & Mechanical Enterprise) was founded in 1971 in Minsk in Byelorussian SSR, Soviet Union.

Finally they're apparently "focus free" bins and set of -1D focus (not at infinity). I presume setting for hyperfocal distance. I guess designed for corrected vision with good accommodation (young solidiers). I previously assumed they were IF previously but apparently not! Obviously not good birding bins.

Holger also reviews these bins

http://www.holgermerlitz.de/six7x40.html