Re: RCX400 f/8 and Focal Reducers
- --- In RCX400@yahoogroups.com, Hi Rod Flat Fielding will remove
your vignetting ,it will not remove the defects introduced with that
FR you are using ie it's for an F10 SCT . Toss the focal
reducer ,dial in your AO unit you can image at F8 all day long!
Rememeber if you can get through 8 minutes you can go as long as you
want because this is the time nessasary to successfully remove the
periodic error to acceptable levels.Balance your scope ,Get polar
alignment set up. Good Luck PS. Pempro has a steep learning
curve but is excellent for analysing your mount !
"rcx400" <rodsrun@...> wrote:
> I know that everybody recommends FRs for astro-imaging to reduce
> exposure times, increase field of view, and flatten the peripheral
> field of view (which isn't supposed to be necessary with the RCX400
> scopes). Old threads I've read, and participated in, describe the
> pros and cons in detail. But is anyone here imaging using an f/8Ted
> RCX400 without a FR?
> I ask because I'm experiencing fairly extreme vignetting using the
> Agos' Antares 0.63 FR optics integrated into the tube adapter whenused
> in front of a AO-8, CFW-8A, and ST2000XM imaging train. With theFR in
> place, I have an effective f/5 optical system, and without the FR Iam
> approximately back to the scope's OEM f/8.makes
> I'm going to try the non-FR arrangement to see what difference it
> to the images I capture, and to my field of view, but I waswondering
> what other's experiences have been without a FR on these scopes.
> Thanks for any real-world anecdotes provided.