20343Re: Need focal reducer help!
- Dec 2, 2003Thanks for the info Jim!
--- In email@example.com, "Jim Thibert" <thibertj@h...>
> I have found with all the ccd optical train, especially when usinga c14and
> st7 that .63 is tough enough let alone 3.3 R/Cbecause
> For the .63, I went to a VSE focuser where the R/C is zero offset
> its inside3Robo
> Good skies-clear eyes
> formerly, www.frenchriverobservatory.com
> W78-55-12 N42-54-25
> C-14@f... (st7-i/cfw8)and TV101(st7-e) on ParamountME with VSE m-
> ----Original Message Follows----
> From: "uwpf23" <uwpf23@y...>
> Reply-To: firstname.lastname@example.org
> To: email@example.com
> Subject: [ccd-newastro] Need focal reducer help!
> Date: Mon, 01 Dec 2003 04:29:25 -0000
> I cannot achieve focus with a Meade F/3.3 focal reducer used with
> the following:
> 1) Celestron CGE-1400 OTA. 3910mm focal length @ F-11 when no focal
> reducer used.
> 2) CCD setup is an ST-7/CFW-8/AO-7 all attached together.
> 3) JMI SmartFocus elecric micro-focuser.
> I've tried the following already:
> 1) Mounted the reducer directly onto the visual back of the OTA
> then attached the JMI, then the CCD gear. Racked the Celestronand
> main focus knob all the way clockwise (mirror moved all the way
> back toward the rear). The image was moving toward focus, but
> could not get all the way focused.
> 2) Mounted JMI focuser first, then the reducer, then the CCD gear.
> Same result.
> Note: I CAN get focus with the F/3.3 reducer through the eyepiece
> a star diagonal visually (NO CCD attached).CCD
> Is my problem that the focal reducer lens is too far away from the
> CCD chip with all the gear attached? Or, is it too close to the
> chip? It seems from the visual eyepiece check that the reducer isspecific
> too far away from the CCD chip. I can't get it any closer without
> removing some of the CCD attachments, which is not feasible for me
> (can't do without the color wheel or adaptive optics).
> Anybody have any ideas on what the cure for this is? If this
> focal reducer is incompatible, anybody have any suggestions forbrands
> that will work and are faster than F/6.3 (already have a .63 fromthis
> Celestron that works fine--just need shorter focal lengths than
> with such a long main focal length to work with!). Would like toget
> down to at least F/4 or 4.5 if possible, as F/6.3 just is nothttp://docs.yahoo.com/info/terms/
> desirable with some objects on the CGE-1400.
> Thanks for any help you all can give me on this!
> Clear skies,
> Wade Van Arsdale
> Little Rock, AR.
> (Registered NewAstro Customer)
> To unsubscribe from this group, send an email to:
> Your use of Yahoo! Groups is subject to
> Add photos to your e-mail with MSN 8. Get 2 months FREE*.
- << Previous post in topic Next post in topic >>