[APML] M20 Image Posted & Question

[<apml@astroshots.com>]

Hello,
I've just finished processing a M20 image that I was finally able to get -
been struggling to get this object all summer.  It's not too easy
considering the Michigan weather, and it's pretty low in the sky at this
location.  This image is a single exposure of hypered LE400 for 50 minutes
through and LX200 12" f/10, auto guided by ST4 using CCDTrack. There's some
oblong stars - and I'm a little disappointed in the chroma distortion - if
you zoom in you'll see stars that are red on one side and blue on the other.
Is this a SCT thing, and/or is there something I can do to minimize this?

http://www.astroshots.com/images/m20_web.jpg

All comments welcomed....

Here's another taking on the same night with an R200 8"f/4 newt with coma
corrector on a G11.  At full resolution this one was pretty badly trailed -
this is a 30 min exposure on unhypered PJ400.  Still working on some
flexure/guiding issues on this setup.  However, no matter how hard I try to
collimate my R200, I still seem to get trailed stars in one corner of the
frame - guiding through a separate scope on a star near the center of the
R200's field of view.  I'm using an Orion laser collimator - is there a
better method of collimating? Is it possible to get a full 35mm frame of pin
point stars using the R200?

http://www.astroshots.com/images/m8_m20_web.jpg

All comments welcomed...


Regards,
Dave Robinson




--  APML Archives at <http://astro.umsystem.edu/apml/>  ---
             Unsubscribe at <majordomo@seds.org>