Hi John,
I recently purchased a new scope, (FL of 2540)and am using a new quide scope as well (FL 325). I am binning both 2x2. I am able to get repeatable positive results with guiding when performing the function in Maxim alone. When I initialize and try guiding within CCDAP, I run into problems with star trails. I have tried altering the minimium move settings as well as the agressiveness, but can't seem to find the right combination. I am probably missing something. Do you have any suggestions?

(Log attached)

Thanks for your help,
Kent

ccdap20080523_003816.log (7 KB, 210 downloads) Log file 5,23,08

Hi Kent,

Getting a new OTA up and running almost always includes some new "challenges"

You have a pretty extreme image scale difference between your guider and your imager. With a guider FL of only 325 mm, as a minimum I would not bin the guider. You certainly will have enough bright guide stars at that FL. I would also change the guide tolerance from 1 pixel to 0.5 pixel. I would try setting min. move to .06, max move to .12 and aggressiveness to .8.

As a diagnostic, check your guiding self-guided using the STL's internal guider. Bin 2x2 here. If you get good guiding there but not with the guide scope, that would be an indication of differential flexure between the guide and main scope. I don't know what kind of OTA you had before the CDK but many reflective systems may have slight mirror movement that can also result differential flexure.

Hope this gives you some things to shake out.

Hi John,

Great suggestions. I realized I was pushing the envlelope a bit regarding the imager/guider focal length. I will guide unbinned and see how things go. I was using a Mewlon 300 prior to the CDK 12.5, but instead of a guide scope, was using the internal guide chip of the camera.

Thanks again John for the suggestions. I'll let you know how things go.

Best regards,
Kent

Hi Kent,

I'm in the process of building my first imaging scope. At this point I have the Paramount on order and am considering placing an order for the CDK 12.5. If you would be willing to share with me your impressions thus far it would be greatly appreciated. My e-mail is brett_wayne@mac.com.

Hope to hear from you. Thanks!
--Brett