I purchased my first Ha scope (Lunt LS60THa) a few months ago and have been loving the Ha experience. So I'm now looking into future plans for... wait for it... MORE APERTURE!!!
I'm considering going the Quark route on this so I can utilize my existing APM 140 refractor. However, after reviewing the details, I ended up thinking the 140, with its 980 focal length, was just going to be too much scope since the Quarks need f/30 so my 140 would be operating at about a 4116mm focal length.
Most days with my LS60 I'm lucky to get over 50x here in turbulent CT. If I use the original Quark, with it's built in 4.2x focal extender, on my 140 I'd be at 75x with a 55mm Plossl. So I'll be hunting around for a bunch of long focal length 2" EPs trying to find ones that will perform at f/30 that I won't get any use from otherwise.
I then noticed that the Combo Quark states it's good from f/15 - f/30. If I use a 130mm ERF and a 2x Focal Extender I'll be at f/15 with only a focal length of 1960mm on the 140. With this config I'd get 50x with a 40mm EP so I can just use 1.25" EPs. This certainly seems like the way to go. But will the view be good at f/15 since everything else ever written about Quarks, or other Ha devices of this type, says they need f/30 or slower?
So, for visual use, does anyone use the Combo Quark at f/15? If so, does it show good detail and/or have you compared it at slower focal lengths? I.E. It works at f/15, but it's better at f/30?
Thanks in advance for any replies!
Edited by bobito, 25 March 2019 - 01:04 PM.