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View Full Version here: : ngc4945, 4976 and 5 others.


alocky
02-05-2015, 04:11 PM
Some nice images of this recently, but here it is at about 1000m focal length, with NGC4976 off to the right, something hiding behind a star top centre and another 4 little smudges buried amongst the stars. This was the first galaxy I ever found, through a 4" Unitron at Lake Moogerah in SE QLD in about 1983.
Anyway - touching reminiscences aside, this was taken in suburban Perth through a 10"f4.5, QSI683, on a G11-G2. About 8 hours in total with 2 hours each LRGB, 5 minute subs for L, and 10 for the others. I'm still having some issues with stray light from nearby streetlights, as there is a bit more data in there, but the background starts to break up into some odd bands and curves if I stretch it much more.
Comments and recommendations welcome!
high res at :
http://www.astrobin.com/174545/B/
cheers,
Andrew

RickS
02-05-2015, 04:44 PM
Nice image and interesting composition, Andrew. I'd be tempted to wind the stars back a little.

Cheers,
Rick.

alocky
03-05-2015, 02:09 PM
Thanks for the comment Rick - I'm never happy with the stars from the 10" on the G11, they're always just a bit out-of-round and the colours at the edges get a bit funky when I combine the RGB channels. I'm still yet to get the hang of the star-mask generating tools in PI so I'm only processing for the extended objects until I sort that out. Still, worth experimenting with some more!
cheers,
Andrew.

RickS
03-05-2015, 04:47 PM
Star masks are a bit of a black art, unfortunately. I have been wondering if it would be possible to do something clever with scripting and the star detection/analysis tools. I should probably finish my ColorMask script before launching another project...

Cheers,
Rick.