Quote:
Originally Posted by glend
As a previous RC owner (RC8), I see bad coma. Good chance the primary is out of alignment. The history of the GSO RCs is pretty clear, never touch the primary if you can avoid it. Your nice alignment in the TAK scope just means you messed up the secondary to make it appear aligned to the messed up primary.
There are numerous RC collimation threads, heaps on Cloudy Nights forum, and a number of illuminated tools to help you re-establish a base position. A new tool recently released is the Teleskop-express RC illuminated collimator,
https://www.teleskop-express.de/shop...elescopes.html
Btw, I have one of these TS devices, which i have used on my Classical Cassigrain and it works well.
I always found the TAK scope difficult to use, mostly because it was not illuminated nor throwing light out the front to align to a target.
There is a thread on the Net that shows you how to make an illuminated target box, a La the ultra expensive Hotech system, which works very well. It uses a white LED in the target to bounce back from the primary to align the primary centre spot to a wall mounted target. If I find the link I will post it here, I had one but threw it away when I sold my RC.
Good luck.
Edit: Found it. Look here,
https://britastro.org/node/16167
Note that the article contains a pdf file link to do you can print the target. |
Thanks for the reply.
That TS device looks good, and I agree the Tak scope can be annoying because of the lack of a light source.
I might try the illuminated target box first to get the primary fixed. Then use the tak scope for the secondary. If I didn't have the Tak scope, I think I'd jump straight to the TS device now. I found it easy to adjust the secondary and see the feedback via the Tak scope and via images, so for now it should do.