They’re cheap because a.) I’m assuming they’re porro prism glasses, which are always more bulky but cheaper than comparable roof prism glasses ( the long skinny ones ) and b.) because, well, they are made from cheaper materials ;). Less refined optical glass, less robust body, less fancy lens coatings, etc.
Presumably they well perform less well than comparable models by Zeiss, Leica or Swarovski. More distortion, more optical color fringing, less refined controls, heavier, not “fog proof”, etc. But if they’re good enough for your uses, then you got a great deal :). Binoculars range from ~$20 to many thousands and the range is there for a reason - not everybody needs a $2000 pair of glasses.
I’ve got what you might call a semi-fancy pair of bird-watching binoculars - Swift Audobon EDs. They retail for around ~$350 American and at the time I bought them were considered sort of “entry-level elite” birdwatching glasses ( i.e. the cheapest “good” glasses, as opposed to a comparable $1500 pair of Swarovskis ). I’ve also got a pair of lower-rung Nikons that cost maybe ~$80 American. The difference between the two is real, especially in higher glare/contrast situations. But the difference usually isn’t profound. It’s more a matter of degree, like progressively fancier stereo speakers. You can often get by fine with the cheaper ones.
a. The components of a binocular lend themselves well to mass production.
b. The materials for average quality optics are pretty cheap – glass, metal, and plastic.
c. They were manufactured and assembled in a country where the daily wage wouldn’t buy you a Big Mac.
What you get for more money with optics is better glass with more exotic materials, better anti-reflective coatings, and lots better quality control in the manufacturing and assembly.
Jeez, this reminds me, I haven’t had a look through binocs since I’ve had cataract surgery. My uncorrected vision, even before the cataracts appeared, was around 20/300, and I couln’t take my glasses off to use binocs. Now my uncorrected vision is about 20/30, so the world should look quite a bit better through them – and without glasses. I think.
Whoo hoo. I have to go digging into a closet and get my old pair.
Absolutely true, magnification means very little in quality binocs. The ability to gather light is much more important, and most cheap models are pretty poor at that.
Also, 30x must be very difficult to hold steady when looking at anything distant. With that magnification you’d probably want a tripod or stand of some sort.