"Richard Crisp" wrote in message
t...
Last night was clear but the seeing wasn't very good.

Still I liked the idea of shooting images and all I had to use easily was
the 18" which is set up 24/7 in the backyard.

So I decided to shoot the Crab in Halpha using 2x2 binning at 0.84
arc-sec/pixel (cm10 @ 3366mm binned 2x2)

Here is what I got: 19 x 10 minutes of Halpha binned 2x2

if I did the math right from a signal to noise perspective this is like
720minutes binned 1x1 (190 x 4) or 12 hours


sorry , I didn't do the math right: 190 x 4 = 760minutes = 12h 40m



I haven't shot flats yet and used one from early september. Don't look too
closely or you will see why I say I need new flats :-)