CGEM, C8, C11, AT72ED, NexStar 5SE
Orion Starshoot Pro V2 Color NexImage 5 / ASI120MC Planetary imagers
My photos: http://astrobin.com/users/Steve/
Quote:Jon, It's not as big of a deal. As long as it can stay in relative focus all night. Many guider programs (such as PHD) actually like you to be out of focus slightly.It'll work as well as any other telescope.
Quote: I think you'll find an OAG to be very limiting in your selection of guide stars.
Quote: Quote: I think you'll find an OAG to be very limiting in your selection of guide stars. I am talking based on my experience. Never ever was this the case with this OAG. There was always a guide star in the field.Finder/guider was good upto 1000mm FL but for anything above I have used this OAG and always got very good results.
Quote:The issue is not focus but mirror flop, if the mirror shifts during the exposure, things are not good... Jon
Ed Thomas Deep Space Products www.deepspaceproducts.com
Quote:Quote:The issue is not focus but mirror flop, if the mirror shifts during the exposure, things are not good... Jon Because he has an Edge HD with mirror locks, mirror flop is not a problem. With relatively similar focal lengths, the SCT/MCT combination is probably a good match.
Quote: Interesting comment regarding 1 meter FL. Finding a decent OAG on this side without going into the $700 USD and up is hit and miss.
Quote:I didn't ask if you were talking on your experience. In my experience, I found that an OAG wasn't the best. It works sometimes, and if I had a rotator it would work all the time.Why are you two always hostile to me?
Quote: Why are you two always hostile to me?
Quote: I didn't ask if you were talking on your experience
Quote: It is very rigid and there is always a couple of star to guide with my Orion SSAG.
Quote: I am talking based on my experience. Never ever was this the case with this OAG. There was always a guide star in the field.
Quote: On the 1 meter "interest", I'm about to use a 1 meter FL scope to guide with
Quote: Not sure if your reference to the Celestron OAG is the one sold in the 80s
Quote:I am not an imager but I wonder about the advisability of using a scope that focuses with a moving mirror as a guide scope.Jon
Quote:Image shift can be an issue on some, but I've never seen image shift on a C5.
Coordinator, Fox Park Observatory
A 50mm Edu-Science refractor started it all...Thanks Mom and Dad!
Celestron CGEM; Various OTA's Various eyepieces; Modified Canon XS; Orion SSAG
My Astrophotos on Flickr
Quote:I will never guide with a moving mirror telescope unless it is with an OAG. In my experience, if the mirror even moves a hair it messes up the frame. It will move slowly if you pass the meridian as well as the center of gravity shifts.I was always having issues with my 90mm Mak when guiding and it had very little mirror flop, if any visually. As soon as I switched guidescopes (after several weeks of trying and trying to get it working), all my problems went away.