M42 & core with only a couple of hours of clear sky!

[Barry-Wilson]

I had some fun a couple of weeks ago when I had the briefest of clear skies in south Devon and could power-up my home observatory.

The following image only comprises 30s and 10s subs and shows that the good old KAF8300 is not quite 'old' technology yet . . . . only having a bit of fun here ? . . . not meaning to start a CCD vs CMOS thread ?.

Each LRGB channel - 60 x 30s and 30 x 10s - with the aim to reveal some of the core without too much complication or fuss and straightforward processing.  Taken with my WO FLT132 at F7, QSI683 and Astrodon filters.  cropped circa 10%.

The bright targets do offer some opportunity to keep us sane.

CS . . . eventually?

Barry

[JemC]

Very nice indeed, controlled the core very well ?

one of my favourites, never tire of looking at it, 

[carastro]

Pretty amazing for those short subs Barry. 

Great work.

Carole 

[tooth_dr]

Amazing. I need to check my KAF-8300, it doesn’t seem to be performing like that lol 

[Barry-Wilson]

7 minutes ago, carastro said:

Pretty amazing for those short subs Barry. 

Great work.

Carole 

Thanks Carole.

The thing to remember is there are 60 subs for each channel, so you get quite a smooth integrated stack (ie stacked the 10s subs separately and used them to blend into the core).  M42 is such a bright target that you do not need very long subs at all to gather a goodly amount of signal.

I sometimes think it is too easy to carried away with a drive for lots of long subs (>300s) when the goal is for sufficient signal vs noise to process the chosen target.  In this example M42 provides an abundnace of signal in a 30s sub.  More is better, but fortunately for this target you don't need that much ?.

[Barry-Wilson]

6 minutes ago, tooth_dr said:

Amazing. I need to check my KAF-8300, it doesn’t seem to be performing like that lol 

? . . . I do have reasonably dark skies too as well as a big 'frac.

[Barry-Wilson]

For those of a PixInsight tendency (it is incurable I'm told) . . . I have started to add tutorials to my existing two - Deconvolution and MureDenoise - on my SmugMug site, here, the first being how to boost star colour with Repaired HSV Separation script.

I do promise to add more now that I'm back on the bike . . .

[PhotoGav]

Very nice Barry. No Ha? Great result. You certainly stir the debate of sub length!

[tomato]

Very nice result indeed,   I always excuse my middling AP results by virtue of my limited total integration times, but your M42 has kind of shot that one down....

May I ask what quality of sky do you have in Devon? I am retiring to Shropshire later this year, and am trying to square the circle of finding a dark sky location vs  not being too remote. I’m aiming to have in excess of SQM 21.3, (Bortle 4) which would be an improvement on my current location.

 

 

[Barry-Wilson]

19 hours ago, tomato said:

Very nice result indeed,   I always excuse my middling AP results by virtue of my limited total integration times, but your M42 has kind of shot that one down....

May I ask what quality of sky do you have in Devon? I am retiring to Shropshire later this year, and am trying to square the circle of finding a dark sky location vs  not being too remote. I’m aiming to have in excess of SQM 21.3, (Bortle 4) which would be an improvement on my current location.

 

 

I have no idea of the magnitude of my dark sky I'm afraid.  I had a quick look on the Dark Sky Discovery website, here, and the site presents a map with illumination from towns and cities.  Totnes is only a few miles from Dartmoor NP (which is contemplating registering/applying ? for a dark skies park status, like Exmoor has recently done).  I am on the edge of Totnes and my garden over looks fields with no streelighting.  The other side of my house there is streetlighting however the house does a very good job of blocking the low-height lights.  The council do switch off the lights about 1am-ish as well.

 

[ollypenrice]

Lovely image in every way. Because it's a justifiably popular target I've had a chance to try it with guests every which way and the bright Trapezium region is very unusual in DS imaging in that you do need short exposures to catch it. Nor do you need all that many because your signal is so strong. It would, I think, be a grave mistake to extrapolate out from this to the conclusion that short subs will always work, but Barry is not doing that.

I really don't think that there is any object which gives me such a buzz to stack and process as M42. Whenever I do it those colours, their beauty and intensity, make my heart sing.

Gorgeous. This is surely why we do it.

Olly

[swag72]

This is a super M42 rendition Barry...... a really top class image ????

[MartinFransson]

This really is an impressive image, not only because it´s smooth and very nice to look at. What impresses me most is the way you´ve blended in the shorter exposures. There is no way of telling that this was not done using one set of subs. Usually I think there are signs of the blending but not here.

[Nick Smith]

Fantastic Barry.  Your processing skills are something to aspire to

[wimvb]

On 22/01/2019 at 21:10, Barry-Wilson said:

For those of a PixInsight tendency (it is incurable I'm told) . . . I have started to add tutorials to my existing two - Deconvolution and MureDenoise - on my SmugMug site, here, the first being how to boost star colour with Repaired HSV Separation script.

I do promise to add more now that I'm back on the bike . . .

Excellent tutorial on hsv repair, Barry. I regularly use arcsinh or masked stretch as initial stretch, but never thought of using both together. Thanks for that.

Also, great image of the Orion neb. I believe that the deep wells of the kaf chip help when shooting this target. It means that you can get away with shorter subs that keep the stars and core in the linear range, but long enough to also get the somewhat fainter parts. With my cmos at f/5, I'd get a blown out core, even at low gain.

[tomato]

16 hours ago, ollypenrice said:

I really don't think that there is any object which gives me such a buzz to stack and process as M42. Whenever I do it those colours, their beauty and intensity, make my heart sing.

I really should get round to imaging this object, trouble is with the Esprit 150 and KAF 8300 a mosaic would be required, and Orion is rapidly disappearing behind the neighbour's house.

18 hours ago, Barry-Wilson said:

I have no idea of the magnitude of my dark sky I'm afraid.  I had a quick look on the Dark Sky Discovery website, here, and the site presents a map with illumination from towns and cities.  Totnes is only a few miles from Dartmoor NP (which is contemplating registering/applying ? for a dark skies park status, like Exmoor has recently done).  I am on the edge of Totnes and my garden over looks fields with no streelighting.  The other side of my house there is streetlighting however the house does a very good job of blocking the low-height lights.  The council do switch off the lights about 1am-ish as well. 

 

Thanks Barry for the info. On the Light Pollution map website your location does not appear to be superior to the locations I am exploring in Shropshire, so that's encouraging.

[Barry-Wilson]

Thanks very much Olly, Sara, Gav, tomato, Martin, Nick & Wim.

10 hours ago, wimvb said:

Excellent tutorial on hsv repair, Barry. I regularly use arcsinh or masked stretch as initial stretch, but never thought of using both together. Thanks for that.

Also, great image of the Orion neb. I believe that the deep wells of the kaf chip help when shooting this target. It means that you can get away with shorter subs that keep the stars and core in the linear range, but long enough to also get the somewhat fainter parts. With my cmos at f/5, I'd get a blown out core, even at low gain.

For my tastes I have found to use the two stretch techniques in combination works best.

4 hours ago, tomato said:

I really should get round to imaging this object, trouble is with the Esprit 150 and KAF 8300 a mosaic would be required, and Orion is rapidly disappearing behind the neighbour's house.

Thanks Barry for the info. On the Light Pollution map website your location does not appear to be superior to the locations I am exploring in Shropshire, so that's encouraging.

You could just concentrate on the Trapezium and De Marian area . . . which in themselves frame beautifully . . .

[wimvb]

13 hours ago, Barry-Wilson said:

You could just concentrate on the Trapezium and De Marian area . . . which in themselves frame beautifully . . .

Indeed a very interesting area. Unfortunately, so far I've always had trees interfering with my imaging attempts, and have not succeeded getting a decent image of M 43 yet.

Btw, it seems that the name of the nebula is spelled both De Marian and De Mairan, and is named after the Frenchman De Mairan. Googled it. ?