From: Mark Gaffney <markgaffney@me.com>

Date: May 18, 2010 7:16:09 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Tarantula nebula..NGC 6744.. Jupiter

Earlier in the night I`d managed a satisfactory unguided image of the Tarantula Nebula with my Nikon DSLR. PA was such that with the large 4310 x 2868 pixel chip I simply slewed to it with the HC & there it was in Live view! I had the camera set at Bulb & ISO 3200 & took a 44 second exposure. Focusing was done on star Acrux previously. I understand that if I`d set my CG-5 mount to Sidereal tracking it would have been better still.

Anyway, here`s the Astro IIDC part of it. Later on, early in the morning I decided to try guiding an image with the DSLR of NGC 6744 just after it`d passed the meridian here. This is a quite difficult southern hemisphere galaxy. So I set up my CRG OAG with the Scorpion 20SOM in the guide port & tried both short & long size nosepieces. The focus was right from earlier in the night for the DSLR but try as I might (even with binning the Scorpion 4 x 4) turning the arm, adjusting the prism angle & sliding the camera in & out, I couldn`t find any stars to guide on. I find getting the right settings for the exposure is like shooting fish in a barrel anyway! There is a real sparsity of stars about this object so I decided to consign this project to the too hard basket. At least with the OAG!? (I have a Kwiq guider in the pipeline hopefully..)

I then slewed back & forth trying to find another interesting object & nearly settled on the Eagle nebula as a subject (perhaps the best choice available at this time) but it was slipping behind trees so I decided to try Jupiter with my Flea 2 colour 640 x 480 pixel CCD. I was a good half an hour until I found an out of focus blob on the screen, etc, etc..

I`m attaching a snapshot of the best I eventually got after taking a number of movies at differing settings (after basic stacking & aligning in Astro IIDC). I think my collimation is definitely doubtful for objects at around this FL..

My Sun images from a couple of months ago exhibited a similar problem with focus..(I will have to seriously look into this..!)

I`ll also attach a version of the DSLR Tarantula so you`re not entirely disappointed after reading of my post...

Mark.