45 degrees of pain

[Deadloud]

My Sky Watcher 90 came with a 45 degree prism, which is fine for looking out toward the horizon ... however even with the scope slid right forward on the mount trying to look at anything higher than 30 degrees or so lowers the eyepiece into bad back territory. (AZ3 mount). I've been looking at a 90 degree prism (there is also a 45 to 90 degree variable available) ... will this alleviate the problem and what does everyone else use/recommendations ?

[ronin]

Usually people use a 90 degree diagonal, however as the mirror is at 45 degrees in these it can get called a 45 degree mirror diagonal. Should be easy put a normal one in but not sure how the optical path would be affected.

Any chance of borrowing one to determine if it is a straight swap or if you woud need a diagonal and extender ?

[bingevader]

Is it the Evostar that you have? Some seem to come with the 90^o prism already, so it must be possible on that 'scope, it would definitely make a difference.

[Deadloud]

Yes, it's the EvoStar 90 ... and no Ronin, no chance of borrowing one I'm afraid  . I'll buy one anyway at the end of the month. It's a standard 1.25" job. Did manage to use the scope in anger for the first time tonight, just at the moon ... extremely impressed 

[bingevader]

FLO do the Evostar 90 with both a 45^o and a 90^o prism, why don't you give them a ring or e-mail them and ask, I'm sure they'd be happy to advise.

Cheers