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Recent content by Eric_D
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Nikon Travelite EX 10x25 CF - why the third strap mounting point?
There's a bit of Japanese in the product guide that translates So more central for hand strap. I guess harness, too, maybe. Maybe the more-central position helps 'bracing' vs shake. See also "string tripod". A binocular manufacturer used to make similar. Military? Zeiss? British? Sniper scope... -
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New Horizons II
These? ENHANCED STEREO BINOCULAR - Binoculars - Cloudy Nights Daiichi Seimitsu Kogyo Riso-1 7x40 3D Binoculars- Eric_D
- Post #283
- Forum: Binoculars
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Need to adjust diopter when switching focus distance?
There is a pair on that auction site that seems to use matched magnification as a selling point ... printed on the top end plate. Royalcraft "magni-matched" 7x50 binoculars- Eric_D
- Post #22
- Forum: Binoculars
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Vintage Binocular Catalogs
I found a lot of catalog and manual pdfs on a russian lens collecting site ...- Eric_D
- Post #11
- Forum: Binoculars
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Measuring/Comparing magnification.
Yes. A phone will work instead of a camera. Crop the two photos to precisely the object, in any image editing app. Save both files. Examine file properties for width & height. Divide the pixel counts. I'm too lazy to go find a ruler! I guess there are "ruler" apps to measure on-screen.- Eric_D
- Post #8
- Forum: Binoculars
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Surfbirds website - down?
Website exists on mail.surfbirds.com www.surfbirds.com gives Cloud flare error in screenshot surfbirds.com refused to connect- Eric_D
- Post #16
- Forum: Computers, Birding Software And The Internet
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A Cure for Swinging Binoculars
Another left-field idea: some kind of adapted sports bra, dyed in your choice of macho camouflage pattern ...- Eric_D
- Post #30
- Forum: Binoculars
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Need help identifying Japanese Manufacturer's Code
I just found J-B191 on some nice (for the price) Bell & Howell 8x40 EWA (510ft) porros. Common, and optically good, if you are lucky with the mechanisms. CloudyNights: Bell & Howell 8x40 extra wide field Bell and Howell 8x40s...finally caught my white whale! The J-1260 may use 'J' as a private...- Eric_D
- Post #6
- Forum: Binoculars
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Need help identifying Japanese Manufacturer's Code
There are companies known as SMC, but not in optics. SMark on the other forum matches SMC to J-B 191.- Eric_D
- Post #5
- Forum: Binoculars
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BaK-4 or BAK4 ?
Schott use N- prefixes to indicate 'lead and arsenic free', and P- prefixes for low 'melting' (or transition) temperature lead and arsenic free glasses for moulding (not grinding) processing. Schott Glass no longer use the name BaK4 instead of BAK4. The Chinese use different chemistry to achieve...- Eric_D
- Post #7
- Forum: Binoculars
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Need to adjust diopter when switching focus distance?
Equations work without data. Call me a 'general algebraist' or 'algebraic generalist'? Let us 'dance on pinheads' together. The Wiki page for Keplerian telescope doesn't even have the equation! If you visualise a graph, you don't need data. I mentioned "1%" above, but I need not have. I made...- Eric_D
- Post #21
- Forum: Binoculars
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Need to adjust diopter when switching focus distance?
Yes, I think you understand me correctly. Perhaps I should have said I am an 'old porro', simple-lens guy ... Equations work, even without data ... Should still work with internal-focus. I first noticed different magnification in left and right channels, when trying to improve collimation in a...- Eric_D
- Post #18
- Forum: Binoculars
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Need to adjust diopter when switching focus distance?
This physical 'backlash' is maybe common with waterproof binoculars that use sliding rubber o-rings, rather than bellows seals. There is some additional friction or drag when focussing. Inevitably there will be more drag on one side than the other, so one eye will change focus sooner than the...- Eric_D
- Post #14
- Forum: Binoculars
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Vintage and Classic Binoculars
How about Korean with sticker? This one nearly fooled me. As a JTII sticker afficionado, I hope BinAstro appreciates it ... fiendish! Source: Prinz 8x40 on eBay.