Telescope Reviews: 120mmF5 Binoscope

QUOTE: Many people would not want to invest four or five times that amount for a premium binoviewer+ EPs to transform a 120mmF5 into a 20X85 binocular. >

Well pointed out , Erik .

For emphasis -- NOT MANY people would consider doing such a thing !

Kenny

Kenny,

That's true. However, the logic for doing so is quite compelling in my opinion. I've attached a picture of my binoviewer equipped NP-127. Note the size (and ease of use) of the system which is most unusual for a 5-inch refractor.

In monoview mode this system it able to take full advantage of its 127mm of aperture and it is capable of yielding a true field of 4.00 degrees at 16x and it is capable of performing very well at any other magnification up to 264x.

Then when you add a binoviewer to it is capable of being used at magnifications ranging from 19x - 264x. The eyepieces that I currently use with my NP-127 and TV Bino Vue give me the following magnification options: 26x, 38x, 55x, 83x, 120x & 189x. To be sure, when this scope is used in binoview mode, the light it collects (i.e., 329 times more than a dark adapted human eye) has to be split between the two eyepieces and this has the effect of reducing the effective aperture of this scope (as a binoviewing system) to 90mm.

So when I binoview with this system it is like using a 26x90, or 38x90, or 55x90 binocular. But how many other binoculars have eyepieces that perform at the level of Tele Vue Panoptics and Naglers with respect to field width, field sharpess and overall field quality? Also, how many other binoculars are as abberation free as a system like this? Also, how many other binoculars can give you crisp binoviews of the planets at powers ranging from 80x - 264x?

So with one system (i.e., optical instrument, tripod & mount) the NP-127 gives me a world class 5-inch apo refractor of unsurpassed portability and versatility. Plus, when used in binoview mode at 26x, 38x & 55x it gives me a great (and very cost effective) alternative to the Kowa Highlander and when used at 100x - 264x it provides a high quality/high power lunar and planetary binoviewing capability that no binocular can I'm aware of can match or surpass. There may be some binoscopes that can outperform it in the high power range but they will of necessity be much larger and heavier systems.

Several years ago when I still had an NP-101 I strongly considered getting the Kowa Highlander with the 21x, 32x & 50x eyepieces options. The reasons that I decided to my NP-101/Bino Vue system to an NP-127 was (a) My telescope would be improved from a NP-101 to an NP-127. (b) My Tele Vue eyepiece set would work with the NP-127 in both mono and binoview modes. (c) At 26x, 38x & 55x a binoviewed NP-127 would essentially give me the capabilities of the Kowa Highlander, and at 83x - 189x it would go far beyond it. (d) This option was less expensive (for me) than going the Kowa Highlander route. (e) And last and perhaps the most important to me, I could have all of these capabilities in one system.

In addition to being able to have room for my telescope, binoviewer and eyepieces in my car, I also have to have room for my binoculars, binocular mounts, tent, sleeping bag, extra warm cloths, food, etc. when I go on overnight or multi-night observing trips. While I may be willing to spend big bucks to get the finest optics I can (within a reasonably portable size range), I'm not will to spend many thousands more for a larger SUV, truck or RV (all of which would get lousy gas mileage relative to my Honda CR-V) so as to be able to haul more astronomy gear. I'm going on my third year now with this NP-127 binoviewing system I'm very pleased with it and plan to keep it for rest of my observing life or unless/until I feel the need to downsize to a smaller and lighter telescope like the TV-85.

Anyway, to conclude, not many people will opt to go the route I did (if for no other reason than it is still quite expensive), but it does have real advantages to it and especially so for someone who is looking to minimize how much gear they have to deal with (without compromsing any essential observing requirements).

John Finnan

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Leica 7x42 Ultravid
Nikon 7x50 Prostar
Swarovski 8.5x42 EL
Nikon 10x70 Astroluxe
Leica 12x50 Ultravid
Zeiss 15x60 B/GAT
Takahashi 22x60 Astronomer
NP-127 w/Bino Vue