32mm or 50mm Guidescope for my setup?

William Optics Redcat 71 ZWO ASI220MM Mini Equipment Guiding
2 replies•149 views
Vinny Vent avatar
Vinny Vent avatar
Hey all, I about to pickup a Redcat 71 WIFD and in anticipation of that I already just purchased the WO 32mm Uniguide guidescope to be paired with my ASI220mm Mini. I thought this pair was fine as I have often read abou tthe 1:3 rule and the calculator on astronomy.tool showed this setup as being that 1:3 ratio. However I have now read a few others saying 1:1 is the "best" to shoot for; if that is in fact the case this would mean I need to exchange for the WO 50mm Uniguide. 

Am I understanding this correctly in that 1:1 is like the "holy grail" target to shoot for? Does this mean I should do an exchange for the 50mm? If some more context helps I will be shooting in a Bortle 8 yard with seeing conditions that generally land in the ok to poor range. Thanks in advance!
Engaging
DanRossi avatar
DanRossi avatar
You should be fine with 32mm. From Bortle 8 you may want to invest in a 1.25" light pollution filter that can also serve as an IR/UV cut filter to reduce star bloat…but try without it first.
Helpful Concise
Vinny Vent avatar
Vinny Vent avatar
You should be fine with 32mm. From Bortle 8 you may want to invest in a 1.25" light pollution filter that can also serve as an IR/UV cut filter to reduce star bloat...but try without it first.

Thanks Dan, appreciate that. And good point on the LP Filter. If I do in fact wind up needing one do you have any suggestions so I have that in my back pocket? Guessing it shouldn’t be anything to strong since it’s doing short exposures.
Related discussions
OAG vs. Guidescope
I am setting up my dual scope rig, and I have a question about OAG vs. using a guide scope. I am using two WO refractors - Z73 and GT71, so the focal length is pretty short. I have been using OAG exclusively this past year. I read Sara Wager's ar...
Discusses guide scope selection and pairing with refractor telescopes.
May 19, 2022
Odd "circle" in imagery when taking photos
Hi all, Starting with: This is a 12” newtonian (1200mm), with a Poseidon-M connected to 50mm (round) filters and an OAG-MAX (with a coma corrector) - 56mm back focus So I’ve been banging my head against a wall trying to figure out what this is… I fir...
Discusses guidescope setup with OAG and filters relevant to author's equipment considerations.
26 days ago