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what scope can work the best for binoviwers?

Started by ref68, 01/31/2011 11:30PM
Posted 01/31/2011 11:30PM Opening Post
Hi All.
what scope can work the best for binoviwers?
I'm thinking ED refractor but I do not have that scope now!
Refet.
Posted 02/01/2011 03:38AM #1
I love using my binoviewer on my refractors, however some refractors do not have enough in focus travel to use with a binoviewer without also using some type of OCA/OCS or Barlow. The down side to that is you can end up with more magnification than you want. The ideal setup is a refractor that can focus without all the expensive add-ons.

The style of binoviewer also matters. The cheaper Chinese binoviewers only need 4 inches of in-travel. The Televue needs a little more than 5 inches. Everything else is in between except for 2" binoviewers.

My advice would be to check through different refractors using an eyepiece you want to use in the binoviewer. Bring a celestial object into focus and measure to see how much further you could have racked in the focuser. You can gain a lot by not using a diagonal, but it is a real pain in the neck at night.

My TAK FS-128 is a good example of a refractor that can focus most binoviewers except the Televue without needing additional correctors.

Don
Posted 02/01/2011 09:58AM #2
That obviously depends on what you want to observe. DSOs require aperture no matter what. Even then you will need a certain amount of power to pick out the details. The brighter objects will be great in a mid sized refractor, but will be lots better in a 10" or larger reflector. A binoviewer splits the light so smaller aperture suffers more on dimmer, extended objects. Larger aperture will suffer from a smaller FOV, but more details can be seen.

refet dehari said:

Hi All.
what scope can work the best for binoviwers?
I'm thinking ED refractor but I do not have that scope now!
Refet.