Looking to buy a simple autoguider - Advice?

[Penguin]

Hi, all,

I have a Skywatcher Explorer 150P (not a PL, as this post originally said) on an HEQ5 Pro mount and have been dabbling in deep-sky photography with an unmodified Canon 450D on and off for a few years. I think a lightweight autoguider might be the best next step for me as I rarely get round stars and would welcome your advice before I commit to anything. I see no point in trying to improve the camera setup with LP filters or anything like that till I can get round stars! 

I believe I am adequately polar-aligned on my pier as it's difficult to differentiate the out and back trails on an 8-minute DARV in both RA and Dec. The star elongation seems to be around the same amount with different sub lengths between 1 minute and 8 minutes so I am assuming this elongation is actually caused by something like periodic error, which I am hoping autoguiding can improve. Am I right in those assumptions?

 

I have not installed the belt-drive mod to the mount though I have recently serviced it for possibly the first time in its life (with a lot of advice on another thread, thanks hugely!). Both axis are pretty free now. There is a small amount of backlash in both which I have not been able to get rid of without also causing binding. I am hoping this won't cause to many problems for guiding.

 

Based on the above, would you suggest the Rowan belt mod, or autoguiding, or something else as my next step? For Autoguiding I was looking at one of these two options:

https://www.firstlightoptics.com/guide-cameras/zwo-mini-finder-guider-asi120mm-bundle.html

https://www.firstlightoptics.com/guide-cameras/sky-watcher-9x50-finder-adapter-zwo-asi120mm-bundle.html

 

Thanks in advance,

 

Alistair.

Edited September 25, 2021 by Penguin