Quote:
Originally Posted by mental4astro
Go-to isn't the only option. 'Push-to' is another. Here instead of having little motors move your scope, you do the work, following a simple countdown timer as you zero in on the target. Both go-to & push-to systems need to be aligned, so there is no advantage or disadvantage there. Even a GPS system needs alignment refinement. What a go-to will that a push-to won't is track (unless your mount already has a tracking system). But a push-to will begin to 'count-up' the misalignment in the same way it did the countdown, so if the target moves out of the field of view requiring it is a simple matter.
What push-to systems have over go-to is usually a larger catalogue of objects, and depending on the system, can learn the little quibbles of a mount & take them into the calculations for its accuracy. These systems are also easy to retrofit to an existing mount too, from equatorial to simple alt-az & dob mounts
Reason I mention these push-to systems is they then give you a wider scope selection. It could mean ending up with a scope that is of better quality, or simpler to setup & takedown, or even a larger aperture, particularly from the secondhand market as a push-to system can usually be easily retro fitted. In the classifieds at the moment there is a 12" dob with an Argo Navis push-to system (I reckon the most powerful push-to there is, & Aussie made!) for $1200.
Argo Navis is also capable of being coupled to a set of retro fitted servo motors to also give you a go-to scope. Many large dob owners go this way too. I've put encoders onto my 17.5" dob & my 8" dob, & I can swap an Agro Navis between each mount, no problem. One CPU, two mounts 
There are other push-to systems available too.
Something more to consider.
Mental. |
Thanks for the advice. A Goto would be better as it would allow me too smoothly take the picture for a long exposure. I will look into this though!
Phobos