Bubble Nebula in H-alpha

[physicus]

Clear slot between 00:45 and 3:45 last night yielded this.  15 x 600s, C9.25/0.63, Atik460, OAG/PHD2, AZEQ6, Baader Ha.  I had a long circular  conversation with myself and read all the forum discussions on 1x1 versus 2x2 binning for this one, and plumped for 2x2.  Adding in some 1x1 data acquired earlier in the week made no real difference, so I left it.  So important to get focus right, which can be time consuming with narrow band (sometimes the filter appears parfocal with my IR block filter, sometimes not), so I always refocus by making short exposures and tiny adjustments on the focuser.  I put a Feathertouch Crayford on the C9.25 when I bought it and while $ painful at the time, it's proved a good investment.  Next project is to try this object at f10 prime focus - with all the  challenges that will entail.  Great object this; the bubble reminds me of those freeze frames of the early H-bombs going off.

[MilwaukeeLion]

I'd frame and hang it, maybe a silver leaf finish to match the core.  Really cool image plus sense of time and effort you put into the shot.  Congrats !

[MartinFransson]

I agree with MilwaukeeLion, frame it! It's got an eerie, magical look to it. The eye in the sky Lovely framed and processed!

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[physicus]

Thanks guys.  I've been sitting too close to the monitor.  There is the whole eye thing going on when you step back a bit.

[ollypenrice]

It's good, but if you couldn't see any gain between binned and unbinned (which isn't surprising given the pixel scales we're talking about) then I'm not sure why you'd go for an even finer pixel scale. What the image needs is more signal and less noise. Slowing the system down isn't going to help that.

However, what I always advise over listening to other people is trying things for yourself, so do it! 

Have fun,

Olly

[physicus]

It's good, but if you couldn't see any gain between binned and unbinned (which isn't surprising given the pixel scales we're talking about) then I'm not sure why you'd go for an even finer pixel scale. What the image needs is more signal and less noise. Slowing the system down isn't going to help that.

However, what I always advise over listening to other people is trying things for yourself, so do it! 

Have fun,

Olly

Your logic is faultless Olly, and rushing to f10 does look silly on the face of it.   But to clarify.  The earlier 1x1 session result (only 4 x 600s) did of its own look 'sharper' than the longer  2x2 session, but very grainy.  Combining that data with the 2x2 data didn't make much difference on this occasion, but to be honest it's all a bit subtle, and I'm with you that - for given seeing conditions and assuming the thing is focused - improving signal to noise is the way to go.   So down that path I'd leave the optical train as is and go for longer sub and total exposure; which you never know, may be what happens :-).  With my scientist/engineer hat on, I tend to judge the result objectively by total info content for a given sky coverage (e.g. micro wispy features visible, magnitude depth, star separation etc); but given the time available (UK/summer), admit I am tending to go out on the occasional flyer to probe the extremes and see what happens (f10).  There's another not entirely logical factor: that when I moved to a reasonably dark site 8 months ago, I budgeted for an SCT and a good refractor - but never bought the refractor (yet !)  - so I'm kinda squeezing the limits and championing the SCT to see what it can do that a refractor can't (?).   I've found Sara Wager's thoughts in this department, and your own discussions on image scale/resolution, very helpful.  This is a great site.

Tim

[physicus]

Staying with 2x2 binning, and 1.5 hours Ha later, plus an hour each of OIII/SII, here's the colour version.   Decided I really need more data in SII and OIII (and Ha!), to expand the peripherals.  Unreliable sky dictated 6x600s for the SII and OIII, but I'm coming to the conclusion Narrowband really askes for 1800s+ subs.

https://www.flickr.com/photos/16835799@N08/20249678989