John K
26-03-2007, 03:07 PM
Well I got out there last night for my second go at the deep sky stuff armed with a newly acquired off axis guider and my 12.5" with thoughts of long exposure postcard looking deep sky images. Little did I know!
It took a full hour to drift align my horseshoe mount and courtecy of the fact that I have only a 5 x Powemate with a 12mm guiding eyepiece, the guide stars where either too small or too faint. Finding suitable guide stars with the off axis guider proved way way more difficult that what I had imagined. Dont know how you guys manage it! Really need a 2 x Barlow. As well, because I have not yet obtained an extension tube, both the eyepiece and barlow need to be fully extended and just manage to reach focus, further exagurating the guide stars looking like seagulls due to extra flex. The other problem was the flexure issue that came/went with the camera hanging off the off axis guider itself as I rotated it around to find guidestars. To top things off battled wind vibration for half the night!
So the name of the game was to crank up the ISO on the 400D and keep things very very short. The only shot I could do any proper guiding with is the Eta Carina shot.
Surprised that I got anything really and on the positive side my drift alignment was not too bad for my first effort. Also imaged my first galaxy and globular cluster even though they are pretty poor by this forums postings, but it's a start and I am hooked.
Going forward need to sort out the guiding thing and learn how to stack and subtrack dark frames, but 100% tracking accuracy will be my first challange.
Comments, advice and suggestions very welcome!
All shots were taken at ISO1600 with built in noise reduction and processed in Canon Zoom Browser EX and Noiseware.
OMEGA CENTAURI - 23 seconds
ETA CARINA - 137 seconds (2 versions)
NGC5128 - Just 21 seconds
SAGITARIUS MILKY WAY - 125 seconds unguided (Sigma Lens is proving great)
p.s. anyone want to sell a 2 x Barlow?
It took a full hour to drift align my horseshoe mount and courtecy of the fact that I have only a 5 x Powemate with a 12mm guiding eyepiece, the guide stars where either too small or too faint. Finding suitable guide stars with the off axis guider proved way way more difficult that what I had imagined. Dont know how you guys manage it! Really need a 2 x Barlow. As well, because I have not yet obtained an extension tube, both the eyepiece and barlow need to be fully extended and just manage to reach focus, further exagurating the guide stars looking like seagulls due to extra flex. The other problem was the flexure issue that came/went with the camera hanging off the off axis guider itself as I rotated it around to find guidestars. To top things off battled wind vibration for half the night!
So the name of the game was to crank up the ISO on the 400D and keep things very very short. The only shot I could do any proper guiding with is the Eta Carina shot.
Surprised that I got anything really and on the positive side my drift alignment was not too bad for my first effort. Also imaged my first galaxy and globular cluster even though they are pretty poor by this forums postings, but it's a start and I am hooked.
Going forward need to sort out the guiding thing and learn how to stack and subtrack dark frames, but 100% tracking accuracy will be my first challange.
Comments, advice and suggestions very welcome!
All shots were taken at ISO1600 with built in noise reduction and processed in Canon Zoom Browser EX and Noiseware.
OMEGA CENTAURI - 23 seconds
ETA CARINA - 137 seconds (2 versions)
NGC5128 - Just 21 seconds
SAGITARIUS MILKY WAY - 125 seconds unguided (Sigma Lens is proving great)
p.s. anyone want to sell a 2 x Barlow?