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Use of a doubler with binoculars

Started by, 01/24/2008 11:29PM
Posted 01/24/2008 11:29PM Opening Post
Hi all --

Things have been quiet here for a while.
Most binoculars have a fixed single magnification which is fine as far as it goes. But Swarovski sells a 'doubler' which is (I assume) a 2x scope designed to piggy back onto one of the eyepieces of a binocular pair. Does anyone have experience with one of these?
They're a bit long, not to mention expensive and perhaps awkward to use. But are they effective?
Thanks for any response.

Bob Polcyn
Posted 02/05/2008 05:38AM #1
Follow up: There's not a lot of info about the Swarovski doubler but one website mentions unscrewing the eyepiece on the binocular (Swarovski of course) and replacing it with the doubler. So, this is a dead end.
The question remains though -- is there a practical way of increasing the magnification of fixed mag binoculars?

I have found a way to bring near focus of binoculars closer for terrestrial viewing. I just look thru the lower part of my bifocals -- works very well.

Bob Polcyn
Posted 02/07/2008 05:27AM #2
Zeiss does the same thing by adding a roof prism monocular to the path after the exit pupil. The beauty of the idea is that any telescope can look thru any other telescope, because the output after the ocular is parallel light, collimated.

Anyone can do this, use a handheld finder or monocular "auxillary telescope" to look thru your bino or telescope. The magnification is multiplied, that is if you use an 8x finder to look thru a 10x bino you get 80x. A handy way to assess the star test of your bino.

For what it is worth, premium binos are usually under one wave, even diffraction-limited like a nice telescope: in fact some binos such as the 10x70 Fujinons are so good you can see the nicely formed airy disk and a couple of diffraction rings. It is also a way to assess the color correction of ED/APOs vs achromat binos.

"--Granted, that's a worse case scenario. The destruction might in fact be ... limited to our own galaxy."