CG5 Tracking capabilites
2 replies to this topic
Posted 09 May 2009 - 05:57 PM
Right now I am able to get 20 min subs and probably longer with my CG-5GT simply using the "all-star alignment" routine. However, this type of tracking is occurring at a measly FL of 480mm and I am using a huge imaging sensor. My skies can probably only handle 5 min subs at the most, but it's nice to know I can do 20 minute subs relatively easily. I am thinking of purchasing an Orion f/9 RC scope which has a focal length of about 1370mm, which is much longer than what I have now. Would I be able to image at this focal length without having to go through the drift align routine and just continue using the all star routine? I am expecting about 5-7min subs at this FL. Also, the 6" RC scope will probably weigh twice as much as my 80ED, which is about 7 lbs. Any thoughts on this?
Posted 09 May 2009 - 06:13 PM
I would hope so... You may have to up the ante on your guide scope, but whatever it takes eh... :money:
Posted 10 May 2009 - 10:36 AM
With guiding, polar alignmnet only influences field rotation. Sensitivity to field rotation only depends on sensor size. If you increase focal length (image size) the motion due to rotation at the corners of the field would increase except that the decrease in TFOV compensates so that the motion at the corners is the same. Getting a different OTA won't affect polar alignment accuracy requirements. Getting a bigger sensor will make accurate polar alignment more important.