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Archives of an email list on the history of binoculars. - page 145 / 150





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> I would be very glad if you were able to send pictures of the fixture you

> made for binoculars without accessible cylindrical hinges to grab.

I do not remember where it is.  The construction used softpointed screws to locate  kinematically, that is, without overconstraint, such that the only remaining degree of freedom is rotation around the hinge axis.  But is was not a completely general construction, in that it was designed for a Trinovid 8 x 40, and just happened to hold the 10 a 40 Zeiss West construction. Retrospectively, it was too much work.  Were I to do this type of work again, I should use source of parallel light, such as a target  close to  infinity, or simulating infinity, and swing the barrels against a transparent plate, such as glass or polycarbonate.  The plate can be set perpendicular to the target with a industrial alignment telescope equipped with a front collar with a plane surface perpendicular to the line of sight of the telescope,  or with an autocollimating alignment telescope, or with a adjustable weapon sight with a similar flat front collar-plate to set the line of sight perpendicular to the transparent plate on which the binocular fronts will be wiggled to find locations of the two optical axes relative to the hinge axis.   The Fujinon UBMM is such a setup, in projection form.  It uses a concave mirror as a source of parallel light. Several folding mirrors are used.  Images of the target are presented to the operator on a groundglass screen, after passing through the binocular.  Adjustments are provided to set the screen perpendicular to the line of sight to the target.

If  a projection method is not used, a comparator for simultaneous viewing of the images is required, such as a set of the various spans of the JTII  "hand collimator"; or a low magnification telescope, with aperture greater than 75 mm,behind the eyepieces of the binocular;or a laterally sliding scope  with reticle, such as the golf scopes of 5 x 20 and similar specifications.  In such a sliding setup, simultaneity through the swing is possible only with coordinated movement of both hands, but is not an absolute requirement, as one can remember where the other optical axis was , in relation to the target, before the lateral sliding of the measuring telescope.  With all of these, one can see relative image rotation, such as results from non perpendicularity of Porro prisms.

--Gordon Rayner


Subject: sale of Deutsche Optik

From: "Mike" <mike@___heoptik.com>

I'm pleased to inform you of the sale of my catalogue business and my resulting retirement.  The new owner of Deutsche Optik is Lilliput Motor Co. (www.lilmoco.com) in Yerington, NV.  They can be reached at 1-800-225-9407.  The War Timers title has been purchased by Talkiing Rock Corporation (www.wartimers.com), and their number is 1-800-225-9417.  Our Deutsche Optik Service (optical repair) business will continue here in San Diego under the leadership of Alfredo Ortega.  Its new address: 3366 Hancock St., San Diego, CA  92110-4304 with phone 619-491-9270.

As for me, I can still be reached for the time being at mike@___heoptik.com, or via cell phone at 858-361-0484.

Thank you for your many years of encouragement and support, and please accept my very best wishes for the future.

s/ Mike Rivkin


Mike, everyone on the list appreciates the contribution that your business has made to our mutual interests.  Don't let your hinges rust.

Messages to Mike should be emailed directly to him, not to the list, please.

--Peter & the list

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