Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: RobertM on Oct 18, 2011, 22:36:55

Title: M42 from High Halden first process
Post by: RobertM on Oct 18, 2011, 22:36:55
This is one of the images taken from Marks earlier this month.

Hyperstar 11 with Canon 1000D@ISO 400 and IDAS LPS-P2 filter

18 x 10s + 18 * 60s + 18 * 300s stacked and calibrated in MaximDL with HDR Composition in Pixinsight.  Need to add a touch or NR and iron a few things out.

Would have had more subs but too much live view drained the battery so it ran out part way through.  Plenty of warts but worth posting.

(http://farm7.static.flickr.com/6114/6258315181_6154563ac3_b.jpg)

Link to full size image: http://farm7.static.flickr.com/6114/6258315181_066845a507_o.jpg (http://farm7.static.flickr.com/6114/6258315181_066845a507_o.jpg)

Title: Re: M42 from High Halden first process
Post by: MarkS on Oct 18, 2011, 22:49:47

Cool!  You've clearly got some excellent data there.

The Running Man is full of colour but I think a bit more colour in the main Orion Neb would improve things.

I love the dust in the background.

Looking forward to the second process  ;)

Mark
Title: Re: M42 from High Halden first process
Post by: Mac on Oct 18, 2011, 23:56:17
Fantastic image.

Mac.
Title: Re: M42 from High Halden first process
Post by: Carole on Oct 19, 2011, 00:02:59
Wow, lots of nebulosity showing up there that you don't often see.

Beautiful image Robert.
Is it me or is the background sky a little pink, or is this because your showing a nebulous area not normally seen?

Carole
Title: Re: M42 from High Halden first process
Post by: The Thing on Oct 19, 2011, 07:26:51
Wow is the only word necessary.

There was a few frames put together of M1 Crab over several years which showed how the gas and dust has moved in a relatively short time. Has anyone done the same for M42? OAS images tend to be done on an annual basis for targets like this so it could be interesting to try. The Running Man's left arm seems to have developed a bingo wing! Was it always like this?
Title: Re: M42 from High Halden first process
Post by: RobertM on Oct 19, 2011, 09:45:38
Mark, that's an interesting comment about the colour.  I think that is due to the tonal compression needed to get the HDR image into 16 bits (then 8 for the jpeg).  Technically speaking the HDR part was processed as a 64bit double then compressed down to a 16bit integer tiff and I've found it difficult to extract any more colour from that section of M42.  The running man by contrast is not an HDR object so hasn't suffered from that compression issue.

Carole - could be you're right, I need a calibrated monitor to verify.  In any case who knows exactly what colour it should be - beauty in in the eye of the beholder with these things.

Robert
Title: Re: M42 from High Halden first process
Post by: mickw on Oct 19, 2011, 11:12:39
Fantastic image Robert, really nice detail in the background as well
Title: Re: M42 from High Halden first process
Post by: Carole on Oct 19, 2011, 11:18:16
QuoteIn any case who knows exactly what colour it should be
Yes I agree with that entirely, could be your colour is right and every-one else hasn't captured it.
I certainly agree with
Quote- beauty in in the eye of the beholder with these things
and this one is beautiful. 

Carole
Title: Re: M42 from High Halden first process
Post by: MarkS on Oct 19, 2011, 12:20:09

Robert,

I agree that it is likely the tonal compression has washed out the colour on the brighter nebulosity.  The hues themselves look correct but they have lost saturation.

My personal opinion on this is that the colours in an HDR image should look very similar to what you would would get if you processed the "old fashioned way" i.e. where you blend separate images together using masks.

Mark
Title: Re: M42 from High Halden first process
Post by: RobertM on Oct 19, 2011, 13:21:36
Mark, It's not that I don't agree, and that is one of my objectives for reprocessing, it's just one of a number of steps I have to get to grips with but ran out of time.

btw, it was merged using masks but that may need some tweeking too.  I really think this area needs more sets of exposures though that poses even more processing issues.

Carole, if I can find some part of the image that is truly black background then I'll recalibrate the image but for now I can't find any.  Also, as I remember from a wider panel in Ha from two years ago, there wasn't any area in that region free from nebulosity.

Robert
Title: Re: M42 from High Halden first process
Post by: Carole on Oct 19, 2011, 16:03:53
Quotethere wasn't any area in that region free from nebulosity.
yes that was what I was wondering.

Carole
Title: Re: M42 from High Halden first process
Post by: Fay on Oct 19, 2011, 16:35:46
That is really lovely Robert, beautiful, perhaps a bit more saturation
Title: Re: M42 from High Halden first process
Post by: RobertM on Oct 19, 2011, 19:30:49
Thanks Fay that's very kind of you.
Title: Re: M42 from High Halden first process
Post by: JohnP on Oct 20, 2011, 12:06:07
Looks superb Robert - loads of brown stuff - very impressive indeed. Looks even better on my shiny new 24inch iiyama monitor.... Nice one - John
Title: Re: M42 from High Halden first process
Post by: RobertM on Oct 20, 2011, 14:10:30
Thanks John.  Btw How does the colour balance look on that shiny new monitor of yours ?

Title: Re: M42 from High Halden first process
Post by: JohnP on Oct 20, 2011, 14:53:56
I personally like it. Like you say 'beauty is in the eye of the beholder'. I love the browns of all that background nebulosity. If anything you could increase saturation a touch. John