thanks Rob - I'm not really worried about the appearance of this sub - but whether or not it is representative of what I should be aiming for. I really wanted to know whether subs like this, if I have 20 or 30 of them, are going to give me a decent image, or if I am better off barking up another tree...
I am very happy with the way the G11 performs - and I haven't even tried to fiddle with it yet. A quick run through PEMpro the other night gave me about +/- 11 arcsecs for tracking. I am eyeing off one-piece worm blocks at the moment - but guided images with the ED80 are pretty forgiving....it will generally guide at +/- 2 arc secs or so - at least as far as I can work out. My image scale is just over 2 arcsecs/pixel and the PHD graph wavers between the first gradation either side of zero for the most part....
Cheers
Adam
Quote:
Originally Posted by RobF
I can't get it to look as good as you've already done Adam. You're really up against in so many ways here:
- Single sub, so no chance to stack out noise
- Tremendous amount of noise (darks, flats, etc would take out a LOT of this)
- sky pollution (poor signal to noise ratio)
- dynamic range (the Trap is totally blown)
- data collected at warmest time of year (although darks would help immensely)
M42 is actually a deceptively tricky beast to image well because it has such a huge brightness variation. A cooled CCD helps with colour noise and dynamic range, but you still need all the grunt work with calibration, stacking etc. Definitely worth learning it all well with the DSLR. Its quite a revelation how much easier it is to work with lots of well calibrated data from a dark sky site.
CCDs are getting better and cheaper in the background while you're learning the longer you hold off. ICNR as JJJ says well worth a go while you're experimenting. The only time I used to avoid it was if I was at a real dark sky site and wanted to make every minute count - better to use library darks then.
Don't ever underestimate the humble DSLR - just look at what Humayan and so many others here have done in the past with them.
BTW, your tracking in that is wonderful. Beautiful round stars even when blown up all the way  |