Thx Guys
David - I used Easy HDR to add the stacked subs of each exposure stack. I have only just started doing this - I used to layer mask and manually perform the HDR. Selective smoothing - I found the HDR procedure introduces a bit of noise - especially in areas with low signal (like the outer edge of the galaxy) so my ptrefered method of selective smoothing is to run Carbonis space noise (or deep space noise ) reduction as a layer on top and then layer mask it and paint through the areas with objectional noise. It is just the same as selective sharpening or multi layer deconvolution blending to mask through sharper areas (I used MLDB on the dust lane) - check Ken Crawfords web site for more info on that.
Greg - Yeah looking at it this morning i can see the green tinge - it is a result of tired eyes and the observatory computer I think (gotta blame something). This is exactly the reason I try and get them on IIS - You cant buy this type of feedback. I just ran HLVG (thx Marc) and it is ok. Yeah I saw the tidal stream in Ken Crawfords image (in fact that was the inspiration for the image) - It is just there in the 8 minute subs. I'll have a play at home and see if I can enhance it just a bit.
Re flats, darks etc - ok I am going to offend the purists here
. I've never found the need for em
. Well ok darks - I used to take a dark library at temperature but I started using SBIG Auto Dark in Series method - ie it tarks at dark at the start of a run of subs and auto extracts it before saving the sub. Provided I take enough subs it works fine and the subs are already calibrated ready for stacking. Flats well - in this iamge obviously they could have been used (green - interesting it was mainly in this cahnnel- i'll have investigate) however any slight gradient I get I remove in processing on a duplicate image, match the ADU of the background with the original and layer mask through the affected corners in the original (to avoid clipping of the central object). If I have an image with nebulosity to the edge (like the 3567 image I took recently) obviously I take flats or if I ma not happy with this method described above I will take them but things with a birght object like a galaxy in the centre I usually process out any vignetting. So plats about 40% of the time.
Thx for the feedback guys. I attached the image with the green removed but if I can tease out a bit more of the tidal stream during the week I might post a repro
Mark.
