SCT Plus Crayford Plus Binoviewers.

[Telescope40]

Hello. Question looking for the usual wisdon I always find on this site. . If I add a crayford focuser to my C 9.25 SCT, would this cause any issue with using binoviewers - as in will they still come to focus Ok.

Thanks as always John

[dweller25]

I live just North of Bury and have a Crayford - you could bring your scope and binoviewers up, fit the Crayford and check it all works - I'm sure it will as SCT's have lots of focus depth.......

[alanjgreen]

SCT will always reach focus with binos, so this will not be an issue. You need to worry about extra "magnifcation" that will further reduce your chances of wide angled views.

The disadvantage of binos (with SCTs) is that the increase in the light path (casued by the length of the bino) causes an increase to the visual magnification at the eyepiece. As SCTs have huge focal length anyway, this increase is not a benefit

Adding a crayford focused will further increase the length of back focus (when added to the length of the binos) and lead to a further unwanted increase in the magnification seen at the eyepiece.

If you intend to go the bino route then a featherouch micro focuser is a better option as this has no impact on the light path length.

[alanjgreen]

And also worry about the "weight", the crayford will push the binos & 2 eyepieces further back away from the scope.

Your scope may then become very back heavy thanks to gravity.

You will need to beware the back dropping like a stone (and also your expensive binos & eyepieces) if you are not careful or "sleepy"

[michaelmorris]

I have a Meade 8" LX200 Classic SCT with a crayford on the back and I can still use by binovieweres in a 2" diagonal.

[Telescope40]

Cheers all. Just the info needed as always

John