Re: [APML] More New Images Posted

[Dean Jacobsen <deanjacobsen@earthlink.net>]

Both shots are very nice John.

The Vixen tube looks to be a winner.  Have you had a chance to take any 
shots in the f/6.4 configuration or with a CCD?

Dean Jacobsen
www.astrophoto.net

At 06:27 PM 7/28/2003 -0600, you wrote:
>     It's been a while since I have done this, but - I have some new images!!
>These are my first-light images on a new mount with a new optical tube.
>Manfed Wasshuber got me interested in the Vixen VC200L as a way of getting a
>longer focal length without all the "gotcha's" of an SCT. Last night's
>effort bore fruit, and all 3 would have been worth posting if I didn't
>insist on manually guiding one of them. :-)
>     The Vixen really does appear to be flat field, I cannot see any
>difference in the star images from centre to edge with tech pan. Vignetting
>is minimal, diffraction spikes included and focus is easy at F9! I used an
>ST4 to guide using a Lumicon NEG. The off-axis images focus up nicely to
>points, instead of the comatic blob found in Newtonians. As a result, it was
>very easy to set up and focus with the ST4 through the NEG. The background
>is a bit uneven with the NGC891 shot, due to my tech pan being over 1 year
>old. Comments welcome......
>
>http://members.shaw.ca/jmirtle/n891.htm - full frame
>http://members.shaw.ca/jmirtle/m71.htm - cropped 50%
>http://members.shaw.ca/jmirtle/equip.htm - Vixen photo at bottom of page.
>
>John Mirtle
>Calgary, Ab. Canada
>
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