I found these tables really useful for exposure times.
https://www.cloudynights.com/topic/5...-maybe-qhy163/
I get some vignetting (maybe amp glow as well) with the 1.25” filters in both the ED80 (at f6.3 with flattener/reducer) and the 8” Newt (operating at f4.5 with coma corrector) but it is all easily processed out. However I knew I wanted some pricey filters (to best deal with LP) so anything larger than 1.25” mounted was unaffordable. Don’t regret the purchase at all. I’m using the 8 position EFW. Works like a charm. Using Sequence Generator Pro to control everything. Still not to the point of pushing “Run Sequence” and walking away but getting closer. I was amazed with the Results the Ha filter gave me (around 3 minute exposures at Gain 139).
Only other thing I remember reading was about matching pixel size to focal length for different seeing conditions. The ED80 could undersample in excellent seeing while the 8” Newt could over sample in bad seeing conditions. The bit that worries me was that oversampling seems to place more empahsis on the mount, which in my case is an HEQ5 which is already operating near to its weight capacity with the Newt. Thus I’m resolved to sticking to my ED80 and maybe using the rather slow f7.65 ED100 for a field of view comparable to the 8” Newt.