[ATM] Binocular Telescope

[mckernan at murdoch.edu.au (Ian McKernan)]

Last weekend i was out with a bunch from Bunbury, and Clive Milne turned up 
for an evening with his 20" Binoscope.

Had a look at Saturn, the Orion Nebula, Tarantula, Eta Carina, "Thors 
Helmet", and later Jupiter among others. To sum up, the views are 
great!  Various expletives were used by the 4 of us who did most of the 
looking (Clive, Dave, Tracy , and me, and three kids) but simply,and to 
understate, the views are really good.

I did a lot of comparing between the 10" of mine, Dave's 16" and the 
Binosaur on the same objects. The 20" f5 mirrors makes a difference (of 
course), but most of what i liked about the views came from the Binoc 
configuration i think. Using both eyes really did it for me.  I think after 
i have done my current 8" and the 11" glass as telescopes, i may try and do 
a matching 11" and try out a binoc. I probably would never try and go as 
big as Clive's though, particularly having seen the set up proceedure. A 
smaller version that is easier to set up and transport would suit me 
better, although 20 " mirrors are nice.......??????

Two things i really liked about the way this is configured though.

First, the way that the top rings rotate inside teflon bearings to adjust 
the interocular distance. Its simple, tight, and seems to work really well. 
If your into aluminium as you material of choice this is a good method.

Thje second thing is the wide field EP's in this application. Started off 
using the type 5 Naglers 22mm, and then the 17 and 12mm versions. The "wide 
screen effect" that you get using these eyepieces (they have BIG eyelenses 
and good relief) and both eyes open is what blew me away, as well as the 
comfort. Its really easy to hog the eyepiece here as with both eyes open 
its like looking into a window, almost normaly, with stars on the other 
side. Much more feeling of depth of field in the view than using 1 eye.

Yeah, if i build one i probably wont be using Naglers, but if i win 
Lotto.......

Seeyahs!