Hi folks I have taken this galaxy over 4 nights but ended up with little data because of poor seeing and tracking, throwing away most of the 3 min. subs. I thought I would post it anyway for comment, this is the first 2x2 binned image I have taken not sure it has any advantages. Taken with 18" Newt. f4.5 with c/c and QHY9 Lum 45 mins. RGB 50 mins each all 2x2 bin.
Clear skies Ken.
Thanks for the reply Frank I think the background varies because of vignetting in the scope and this is my first attempt at flat fields there maybe some red on the left side but the rest looks blue on my monitor. Hagar you are right 2x2 binning dosn't seem to give the performance gain a big pixel should have, also it seems to show up more hot pixels anyway I paid for a 9 mega pixel chip not 2.
Clear skies Ken
I find binning 2x2 and 3x3 with my SBIG provides significantly more data for the same exposure time. When I notice it most is positioning a FOV when 5 sec exposures at 3x3 will easily show any NGC object where as 1x1 it's borderline with some fainter mags.
.... also sometimes I bin 2x2 when conditions are poor because I'm not getting nay more data at 1x1 due to my long focal length and the poor conditions. So using 2x2 gives me more data, faster downloads (not an issue for your USB camera), and sharper image to work from.
Interesting Roger you have good experiences with binning I also use 4x4 for locating the object. I think I read on the Qhy forum that 2x2 gives a increase in sensitivity of about 1.4 on the QHY9, one imager was complaining about extra artifacts and hot pixels so maybe the camera and software design also has a bearing on this.
clear skies Ken
Interesting Roger you have good experiences with binning I also use 4x4 for locating the object. I think I read on the Qhy forum that 2x2 gives a increase in sensitivity of about 1.4 on the QHY9, one imager was complaining about extra artifacts and hot pixels so maybe the camera and software design also has a bearing on this.
clear skies Ken
I hadn't considered that different cameras would have a different amount of sensitivity benefit (relative to their 1x1 sensitivity of course) at different binnings compared to other camera's. Interesting. It really goes to show then that everyone knows their own equipment best and that doesn't necessarily translate to other setups
Thanks Marc and Roger I will test some more with 2x2 the binning with the 2m focal length of the 18" and small pixels of the qhy9 the old routine of using 2x2 for colour and 1x1 for luminance to speed things up still holds true for the correct pixel size/ focal length I guess.
Clear skies Ken.
That's a nifty image there Ken, its a shame the seeing ruined some of your data and you had to discard it. Still, a worthy effort and well worth posting here for us to have a look
I thought I would post it anyway for comment, this is the first 2x2 binned image I have taken not sure it has any advantages
. Taken with 18" Newt. f4.5 with c/c and QHY9 Lum 45 mins. RGB 50 mins each all 2x2 bin.
