Amaranthus
09-08-2014, 11:15 PM
One of the southern gems, this globular cluster in Pavo is arguably even more spectacular than M13 (but behind Omega Centauri and 47 Tuc), at least to observers in Australia! It covers an area similar in size to the full Moon, and lies 13,000 light years from Earth.
Taken using an ED80T CF astrograph with a Sony NEX-3 DSLR (ISO 3200)
240 x 30 sec subs (guided using PHD2 and an Orion SS G3 mono, 46 additional subs were discarded)
Captured and pre-processed with flats (light box), bad pixel map and bias in Nebulosity. Post-processed in StarTools.
Full details and high rez version here: http://www.astrobin.com/112389/0/
------
I've been having problems with flexure in my system, so will soon be converting to an OAG!
I used 30 sec subs because it's a pain to do longer with the Sony NEX-3 as it has no remote control. It is possible to go with longer subs using a mechanical shutter hold (rubber band and thimble! with scope covered after each shot), but it's sometimes more hassle than it's worth! For an example of 3 minute subs using that method, see M25 here: http://www.iceinspace.com.au/forum/showthread.php?t=124228
Anyway, this time I opted to go short and many, with high ISO, especially given that I was shooting with the Moon at 40% phase and in light-polluted skies.
Taken using an ED80T CF astrograph with a Sony NEX-3 DSLR (ISO 3200)
240 x 30 sec subs (guided using PHD2 and an Orion SS G3 mono, 46 additional subs were discarded)
Captured and pre-processed with flats (light box), bad pixel map and bias in Nebulosity. Post-processed in StarTools.
Full details and high rez version here: http://www.astrobin.com/112389/0/
------
I've been having problems with flexure in my system, so will soon be converting to an OAG!
I used 30 sec subs because it's a pain to do longer with the Sony NEX-3 as it has no remote control. It is possible to go with longer subs using a mechanical shutter hold (rubber band and thimble! with scope covered after each shot), but it's sometimes more hassle than it's worth! For an example of 3 minute subs using that method, see M25 here: http://www.iceinspace.com.au/forum/showthread.php?t=124228
Anyway, this time I opted to go short and many, with high ISO, especially given that I was shooting with the Moon at 40% phase and in light-polluted skies.