I had one clear night (out of 9) over Easter so I returned to one of my favourite targets.
27 x 5minutes. Modified Canon EOS350D on Celestron C11 with F6.3 focal reducer. No filters (except IR).
(http://gallery.orpington-astronomy.org.uk/albums/userpics/10046/m51_180409.jpg)
For comparison, here is the one I took in France last Easter:
http://gallery.orpington-astronomy.org.uk/albums/userpics/10046/M51_iris_280308.jpg
So what's the main difference? Last year I was using an unmodified EOS300D - this year I'm using a modified EOS350D. My guiding has also improved - this year I'm using a modified Toucam on a 300mm lens - last year I was using an unmodified SPC900 on a 300mm lens with x2 converter (giving 600mm).
If I manage to get to Kelling Heath, I plan to take a few more subs :-)
Mark
Mark, that is absolutely stunning, the colours and detail are so rich, love the dust lanes. there's a bit of coma in there around the edges, but the galaxy itself is incredible.
Fantastic work!
Daniel
:O)
O my gosh...! Superb Mark - Worth taking all the kit to France if only for that one night... I love the fuzzies in background....
Very nice mark and nice and noise free, a Comma correcting reducer surely is a must now heve you looked at the non-Celestron and Meade ones they are meant to be a lot better.
Chris
Really fantastic, Mark. I thought the first one was good!!! You always pull the rabbit out of the hat!
Thanks everyone, for your comments.
Chris, yes the coma is really bugging me now. I'm going to experiment with doing an accurate collimation and then a series of experiments with various reducer to CCD distances. Failing that, I'll buy a different corrector - do you know of any, compatible with the C11?
That's really impressive image Mark, especially for just over 2hrs exposure from a DSLR.
Though it doesn't help at F6.3 you might want to try an MPCC at F10, it seems to work quite well with the C9.25 and 450d. Will bring it along to Kelling in case you want to try it out.
Robert
very nice
Further sharpening gives this:
(http://homepage.ntlworld.com/the_shelleys/Astronomy/m51sharp.jpg)
What do you think? Is it worth the trade-off in extra noise?
Mark
Why not the best of both...
Make a copy of the original. Take the original and blur it slightly to reduce the noise (but not loose too much detail), sharpen the copy for detail (don't worry about the noise too much). Stack the blurred one over the sharpened and adjust the opacity so that the sharpened one shows through just enough to reveal the detail. Voila, you have the next Astronomy now picture of the month ...
Mark - they both look superb to me... Robert's suggestion is a good one.. Your DSLR imaging seems to have really jumped up a notch or two over the last few images.. I of course put it all down to that brilliant guide cam that you bought... :-) Nowt to do with your skill or processing capabilities....
John