Quote:
Originally Posted by Ross G
A very good looking photo Peter, especially coming from Sydney's dirty skies.
Amazing sharpness!
Ross.
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Thank you Ross.
Rather than give a glib reply, I think this is worth a few more words for the many of us who don't have rural estates or want to drive for a few hours toward dark skies with a smaller rig.
Deep-Sky is indeed possible from urban skies. You just have to work a lot harder and the nice thing is, your imaging system's resolution is totally unaffected by light pollution.
And if you choose to work in narrow band the problem goes away, street-lights, full-moon and all!
But for "true colour" the hard parts are exposure times (2-4x longer for the same S/N) and gradients ( PixInsight's tool is a marvel to behold). Sure I'd prefer a sublime dark site...but good luck with cleaning filters, changing focal reducers or entire optical systems, etc....
Worse case for me when things go wrong (and they do!) is it's all a few metres away rather than a few hours.
Pivotal to an "urban system" are maximising signal and reducing the noise.
In a nutshell: large and as perfect optics as the budget will allow, excellent tracking, high QE/low noise camera, long well-calibrated subs. Of course if you have all of the former and a dark site...well, Valhalla!
I have tried using DSLR's...pretty nice ones too...but their intrinsic noise simply will not cut it for me in urban skies.
Deep sky from the 'burbs"? A good 'scope and cooled CCD can/will produce the goods.. the linked image you kindly commented on says it all.