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"HD" binoculars (1 Viewer)
- Thread starter nfbirder
- Start date
Kevin Purcell
Well-known member
It's just a marketing term.
It may or may not imply the binocular has ED glass. It basically meaningless as you need to check the specs to see if that is the case or not.
It may or may not imply the binocular has ED glass. It basically meaningless as you need to check the specs to see if that is the case or not.
brocknroller
porromaniac
I'm wondering if optics company do?
It depends on who's using the letters. For the Leica Ultravid HD, the company is saying that it means three things: (1) redesigning the housing to cut down on stray light, (2) increasing the light transmission by 3 %, and (3) using fluoride (FL) lens glass.
Source: http://www.bestbinocularsreviews.com/leica-binoculars.php#hd_lenses
In the case of the Bushnell Ultra HD, they are using the letters to designate their "RainGuard® HD water-repellent lens coating," which besides repelling water, "averages 7.25% more light transmission than Nikon Monarch across the entire visible light spectrum" (so you know whose business they are trying to cut into, the very popular Monarch series). The Ultra HD also has ED glass, and that's a bigger deal, particularly on the 10x42 model since CA goes up with magnification.
My take is that "HD" is a marketing term rather than a technical term like it is for "High Definition TV". Optics manufactures can make it mean anything they want, but in general, it's another name for bins with "ED" glass.
Some other names are "XD" (Vortex), "FL" (Zeiss), and
"L" (Canon 10x42 IS bin). The latest entry into the field is the Theron Wapiti APO-ED, which uses "APO," meaning it has has better correction of chromatic and spherical aberration than common achromat lenses.
http://en.wikipedia.org/wiki/Apochromat
Since that term is used a bit differently with "APO" telescopes, some take exception with its use in bins, whose shorter focal length make it impossible to eliminate all false color (apochromatic = without [false] color). So it becomes yet another marketing term.
Since no company to my knowledge, except Minox, states the exact type of extra-low dispersion (ED) glass they use, there is no way to compare different bins with extra-low dispersion glass on paper. Even the terms "Flourite" can be misleading, as Henry explained here (post #9).
http://www.birdforum.net/showthread.php?t=187425
So take it in general as an improvement from the normal glass lens bins in the companies line up, but again, beware that it's a marketing term, so comparing two bins with the "HD" designation is not necessarily comparing apples to apples.
Brock
P.S. I wrote this before seeing Kevin's post. Being more long winded, and having to check references, he beat me to it (not the first time either!).
P.P.S. Welcome to Birdforum!
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Thanks for the replies. I figured it was essentially meaningless.
Same thing with various labels regarding coatings. People seem to use terms like "multi-coat" or "fully multi-coat" as if they describe exactly the same thing from bino to bino. They do convey some meaningful information, but surely not nearly as much as people seem to think? I can't imagine that coatings are uniform from one company to the next. I mean, I can dip my lenses in peanut butter and call it "coated"...
Same thing with various labels regarding coatings. People seem to use terms like "multi-coat" or "fully multi-coat" as if they describe exactly the same thing from bino to bino. They do convey some meaningful information, but surely not nearly as much as people seem to think? I can't imagine that coatings are uniform from one company to the next. I mean, I can dip my lenses in peanut butter and call it "coated"...
Kevin Purcell
Well-known member
Multicoated means the AR coatings are multilayer rather than single layer MgF2
Fully multicoated means all glass air surfaces have AR coatings.
The merely multicoated often coated the lens and omitted the prisms. Even worse the revealingly devious multicoated the exterior objective and ocular surfaces (that you could see) but left the majority of surfaces without AR.
So fully multicoated is (or rather was) actually a useful distinction.
Today you'd expect any serious bin (by that I mean anything over $100!) to be FMC.
That said AR coatings though vary a lot depending on age and manufacturer from three layers up to 60 or more. FMC or MC doesn't tell you anything about that.
Fully multicoated means all glass air surfaces have AR coatings.
The merely multicoated often coated the lens and omitted the prisms. Even worse the revealingly devious multicoated the exterior objective and ocular surfaces (that you could see) but left the majority of surfaces without AR.
So fully multicoated is (or rather was) actually a useful distinction.
Today you'd expect any serious bin (by that I mean anything over $100!) to be FMC.
That said AR coatings though vary a lot depending on age and manufacturer from three layers up to 60 or more. FMC or MC doesn't tell you anything about that.
vop
Well-known member
Hmmm... maybe I should try that. Or why not peanut butter and chocolate! :-O
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