Oh, so good but then.....

[Hairycamel]

I recently picked up a set of William Optics binoviewers from ABS and have been itching to try them out. Anyway, it was clear last night so I set up my Celestron C8 and next to it my WO Megrez 110 doublet. First light in the C8 was nothing short of astounding. I got M57 in both scopes and observed for a while in Cyclops mode then put the binoviewers in the C8 with the included pair of 20mm EP's. I did notice a drop in brightness due to the beam splitting, but I happily sat there for about 20 mins having the most relaxed look I have ever had through a scope.

Anyway, I then tried them in the Megrez and they would not come to focus so I thought no problem, and attached the 1.6 barlow that came with the binos for such occasions. No such luck for me and they still do not have enough inward focus.

Anybody got any creative ideas about barlow sizes/placement in the optical path? I understand that correctors are available but I'll soon be spending what I paid for the binos so I dont really want that!

[Matt Scunthorpe]

Sounds like you had a good night with the 2 set up together. I dont know anything about binos, but this will bump the thread so hopefully you'll get the help you need.

[Stardust]

I've used those binoviewers in three refractors and they all need a 2x barlow to reach focus. This is new to me so not sure about correctors but like yourself, I din't want to spend a load more just now. I did try a 2.5x powermate and had a very interesting effect, it gave a lower power view on the Moon, need to experiment more.

[Peter Drew]

The reason that the Powermate Barlow gave a lower power is that it is a telecentric, this means that it produces a 2.5X effect almost regardless of spacing before the eyepiece. A standard Barlow, by comparison, is very sensitive to position, the further away from the eyepiece the greater the magnification. A binoviewer has a significant light path, a standard Barlow placed in front of it produces nearly 3X its face value.

[Stardust]

Thanks for that, I think it will be useful to be able to have a lower power. I did notice the 2x barlow was producing more than that.

[Hairycamel]

Thanks for the bump Matt. Do the rest of you think then that a Powermate is a better option than a barlow to go with?