Having started EEA Observing just over 2 years ago, I finally felt far enough along to acquire a 5-station ZWO filter wheel and set it up for a shake-down run last night in my Bortle 8 (SQM 18.5) skies.
As I was setting up the filter wheel, spacers/adaptors and coma corrector, I found I was missing the ZWO M48 T2 16.5 mm extender needed to get the optics train to be as ZWO recommends - 55mm from the coma corrector. I managed to cobble together some spacers as shown below and managed to get about 51mm. See Image 1 below.
So Question 1 is: Given that I was able to achieve focus, how sacred is the 55 mm versus the 51mm that I used? I do have the missing extender on order so I'll have it at 55mm in a few days.
My Question 2 relates to focusing. Right now I have 2 empty slots in the wheel. One will remain empty, the other will be occupied by a OIII filter. I noticed that I had to adjust my focus between viewing with no filter versus when either the L-eNhance or H alpha was in use. Will I soon also notice that I'll also need to refocus for each individual filter?
Take a look at the first screenshot below - See Image 2 . This was taken while attempting to adjust the Live Stack Histo with the L-eNhance filter in place. You can barely see the nebula and there's virtually no color.
Edited by GaryShaw, 22 September 2020 - 03:01 PM.