Been playing with my image of m27 again - I resized up & then sharpened a little using 'High Pass Filter technique - Aim was to see how much of outer neb I could show. also monochrome for comparison. I know it's probably overdone & noise is showing through & also guiding errors more evident but not bad for a £250 camera. Pretty pleased...
John
(http://homepage.ntlworld.com/john.punnett/graphics/oas/m27_invert.jpg)
John, there are eruptions all over the place on the mono one. Lots of detail
Fay
Great detail John. Really nice.
John,
Your results are very interesting.
Your 15x5min Ha is clearly showing the jets. However, I'm sure I couldn't see the slightest hint of jets on my 18x5min with the modified Canon (but I will go back and see just what I can tease out of my image).
As far as I can see there are 2 main differences that could explain this:
1) Quantum efficiency: You are receiving more signal because more photons are converted to electrons.
2) Thermal noise. You have a cooled camera so your Ha signal rises above the much lower noise level.
Mark
Could have compared my M27 with yours, John, & Mark's but I only did 7x300secs. Half of what you both did.
Hi Mark - Yep I think Chip in the atik 16ic has very good quantum efficiency - cooling obviously helps. What about focal ratio I was imaging at F6 with my MN56 (5-inch aperture)...
John
PS - I might do a few test subs at DSC so see what difference dark skies bring. Incidentally I took no darks with this image (only flats)