Binoviewers from Andrews Comms

[allan gould]

Has anyone had a chance to look through the cheaper ($269) binoviewers from Andrews Comms. I was tempted by these but have no idea how they stack up against the Saxon or WO binoviewers. Any comments would be extremely helpful.
Regards, Allan Gould

[janoskiss]

Looking at the pic of the Andrews unit in S&S, they appear to be essentially the same as most of the budget binos around, including the WO. The WO might have better EP holders, and you get a pair of EPs with it and a 1.6x corrector (to help reach focus) for $350 from Frontier Optics. I'm not sure if the Andrews one comes with a corrector. You'd need one to use it in anything other than an SCT.

Even with a corrector, you might have problems reaching focus in a refractor or Newt, and might need to use a barlow or other attachment; Cheapest one would be a barrel extender to go between the bino and the corrector lens which increases magnification and pulls the focal plane out further. Another thing that varies from brand to brand is clear aperture, which can range from 19mm to 22mm. The 22mm CA of the Burgess C unit that I have is enough to illuminate the field of 25mm plossls without any noticable vignetting (or 19mm 68 degree wide fields). But slightly smaller CA might might mean better baffling. :shrug:

Note that you will not get low power views with BVers in most Newts and refractors. The longest effective EP focal length you will be able to use will be about 15mm, but more likely 13mm. (You can get low power correctors but I don't know if they work and they are not cheap.)

The Saxon unit is inferior: heavy, poor optical quality, small clear aperture.

[allan gould]

Thanks for that Janoskiss - I should have been more explicite in stating which equipment I would be using the unit on. I will use the binoviewer only on
8" and 10" SCT telescopes. What would be the best planetary eyepiece for using the unit on? I was thinking 10mm eyepieces as I want it mainly for Jupiter/Saturn.

[g__day]

I bought some yesterday from Lee, now look how cloudy the skies are. Will give you a review once skies clear up!

[janoskiss]

Did yours come with an optical corrector? What scope are you going to use them in?

[g__day]

I tried them tonight when the weather cleared for just a moment. So these are the $265 bino viewers (as opposed to Bintel's $1,995 version). I used with a pair of 11mm 80 degree lens (also from Andrews) which was probably overdriving my little scope for this ****ty weather.

They are just... special. Its hard to describe, vision has more fullness and depth, I was definitely smiling and thinking 1) god I must get another Vixen 22mm LVW 65 degree lens and try them and 2) what must these be like on nights with good seeing?

I am using a little 5" Mak on a motorised eq 3-2 on a home built pier

http://members.optushome.com.au/mowglhi/piccys/space/DSC00001.jpg

Janokiss, no they did not come with any optical corrector and on a MAK given all its focusing play I was right guessing I wouldn't need one. The tube is threaded to hold a filter. Both eye pieces seperately focus. Unlike the more expensive version there is no 1.0 -> 3.0 magnifier inbuilt (that would be nifty!).

So I spoke to Lee and asked were binoviewers on a 5" MAK absurd (will be better used on my next scope). Lee was kinda adamant no it would be good viewing and he was right. Initial tests are favourable. I think a sturder mount would be much better (given the eyepieces I used have fairly short eye piece relief, so you are pushing into the lens) and wobbles might occur if you mount and tripod/pier aren't firm.

Sigh, I think this path is going to have me spend double on lens!

Need a few more nights to get a better feel for these babies!