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Filroden

NGC 2174 Monkey Head Nebula in Ha (plus WIP HaRGB)

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I wasn't sure whether to post this as I can't seem to get the image I see in PixInsight to export and look the same as a TIFF or JPG, even if I take a screen shot. My image in PixInsight has a darker background that also looks smoother. Anyway, and suggestions for processing and getting images from PixInsight in a repeatable way most gratefully received!!

  • Taken on the evenings of 7 January 2018 (5 subs) and 9 February 2018 (25 subs).
  • Equipment: Skywatcher Esprit 80 with the ZWO 1600MM-C using an Astrodon 3nm Ha filter mounted on the AVX with OAG guiding
  • Exposures: 30 x 240s Ha at unity gain
  • Processed: Pixinsight and Photoshop

large.5a800a1b36695_NGC2174_20180209_v12Ha-2.jpg.d57a43ca2b909ff0710acbb8da2269ce.jpg

And the WIP HaRGP (see post further down for details):

5a8317306b514_NGC2174_20180212_v2HaRGB.thumb.jpg.0d479dc66faa343973a2f077697d2b0b.jpg

Original version posted:

large.5a7f2c551b426_NGC2174_20180209_v10Ha.jpg.ae201fc3bf6f5074f2c7402f3319e6d8.jpg

Edited by Filroden
Added latest version of image to address background issues
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I like your shot of this object - I've only recently tried it myself. Many say it's boring - I think it's quite interesting as it really does look like a monkey.

I've never seen a decent rendition of images at the quality scale available on forums.

I normally look for a link to the submitter's website if they have one or I look for an Astrobin link etc. where they they can upload better quality images.

It's a shame really as the whole point of posting is to get some advice and a useful critique - you can't really do that at 1024 pixels :-) but it's better than nothing I suppose.

One day size won't matter....... :-)

David

 

 

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44 minutes ago, David_L said:

I've never seen a decent rendition of images at the quality scale available on forums.

My fault. I accidentally left a setting on during export which limited the image size. Here's the proper size of the version above:

5a7f3f2114901_NGC2174_20180209_v10Ha.thumb.jpg.e26f64dde292e961af4540d09022f4ab.jpg

With a further curves adjustment to tame the background...

NGC2174_20180209_v1 1 Ha.jpg

Edited by Filroden
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Nice shot.  I did an Ha of this too--a strange nebula as it sort of pops up out of nowhere.  Your background looks good to me.  Though I think you went too far with the last image. careful not to clip the faint extensions below the Monkey's shoulders (upper part of your image as the monkey is hanging upside down from a tree).  Also....did you use noise control...maybe TGV?  Maybe a bit heavy?  while this nebula is not big on structure--there are some dark lanes and threads in the mane, as well as the iconic Hubbell image of the...snail?  near the Monkey's chin.  I found it challenging to get a sense of depth in the nebula with just Ha--trying for the gassy look as opposed to the opaque.   I think the OIII and SII will take your image to the next level.  Mono Ha does not do this one justice.

Rodd

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1 hour ago, Rodd said:

Your background looks good to me.  Though I think you went too far with the last image. careful not to clip the faint extensions below the Monkey's shoulders (upper part of your image as the monkey is hanging upside down from a tree).  Also....did you use noise control...maybe TGV?  Maybe a bit heavy?

Thanks Rodd. Maybe I need to dial back a few steps and apply less noise control. It looks ok on screen in PixInsight but as soon as I move to another package, or upload it here, then it really becomes noticeable.

I think it looks like a monkey either way up. In my orientation its a lemur with a bad hair day, and upside down it looks like an orangutan.

I still need to invest in OIII and SII filters so my next clear night I'll get some LRGB and see if that can give it some depth.

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4 hours ago, Filroden said:

My fault. I accidentally left a setting on during export which limited the image size. Here's the proper size of the version above:

5a7f3f2114901_NGC2174_20180209_v10Ha.thumb.jpg.e26f64dde292e961af4540d09022f4ab.jpg

With a further curves adjustment to tame the background...

NGC2174_20180209_v1 1 Ha.jpg

Not seeing the difference here but “every little bit helps” 😊

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3 hours ago, Filroden said:

I still need to invest in OIII and SII filters

Definitely!  Narrowband is much more forgiving of light pollution, seeing conditions, Moonlight, and  even passing clouds.  They are allot of fun.

Rpodd

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Much happier with this reprocess (slightly less cropped). Basic error right from the start: it was the noise reduction but only because I'd lifted the black point too high during the stretch. I hadn't clipped but it was so close that any processing after this point started to degrade the background. For the image below I did not adjust the black point until the very end. This also meant that I did not need the noise reduction. What a viscous loop that mistake caused!

large.5a800a1b36695_NGC2174_20180209_v12Ha-2.jpg.d57a43ca2b909ff0710acbb8da2269ce.jpg

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12 hours ago, David_L said:

Not seeing the difference here but “every little bit helps” 😊

Oops! I've just looked at this on my PC monitor instead of my phone - I DO see the difference :-)

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10 minutes ago, Allinthehead said:

I really like that last version Ken.

Me too. I knew I was doing something fundamentally wrong on the first process. I’m so out of practice processing that the basic mistakes are creeping in! Even though I’ve read Olly’s advice about doing the black point last a dozen times it’s just too tempting to do it earlier.

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1 minute ago, Filroden said:

Me too. I knew I was doing something fundamentally wrong on the first process. I’m so out of practice processing that the basic mistakes are creeping in! Even though I’ve read Olly’s advice about doing the black point last a dozen times it’s just too tempting to do it earlier.

What i usually do is adjust it to see what it will look like and then put it back.

It's amazing how a little error early on has such an effect on the final image.

After every step i try to examine all aspects of the image to be sure all's well. I then duplicate the image so i can always go back a step and usually end up doing a blend of different images for the final one as more often then not i push the data too far.

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Lovely Ha mono Ken :thumbsup: . . . I'd be tempted to rotate it 180degs though :drunken_smilie:

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9 minutes ago, Barry-Wilson said:

Lovely Ha mono Ken :thumbsup: . . . I'd be tempted to rotate it 180degs though :drunken_smilie:

Thank you Barry :)

I checked yours and I think it looks more like a monkey head in this orientation. A very cheeky monkey with a big smile and very unruly hair. 🐵

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Another clear night last night allowed me to capture 20 x 120s each of RGB and L. I haven't had time to process the data properly but I wanted to see what the above Ha image would look like in full colour. This is just a quick RGB combine, with a single ABE gradient extractor, colour calibration and various shades of blending the Ha into the RGB including some saturation work. I did not use the L data as there isn't enough yet and I did no noise reduction.

The whole set of data needs full processing but I need at least one more night of data before it's worth doing that. The individual RGB integrated images need to have gradients removed, the Ha and L data need de-convolution. The background does need some noise reduction but not until I have more data to strengthen the signal. The image needs an L layer to make blending of the Ha better.

Still, I like it even though it's only a WIP at this stage. I now have a very red faced cheeky young monkey!

5a8317306b514_NGC2174_20180212_v2HaRGB.thumb.jpg.0d479dc66faa343973a2f077697d2b0b.jpg

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Very nice image, and nicely framed.  Perhaps the stars are a tad over-saturated????

Chris

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19 minutes ago, cfpendock said:

Very nice image, and nicely framed.  Perhaps the stars are a tad over-saturated????

Chris

Thanks Chris. Yes they are :) Byproduct of the quick process. I cheated during the stretch and combined Arcsinh and masked stretches which give very intense star colours. I’ll be using more traditional methods in the full process.

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What a fascinating patch of sky!  Who said it was boring?  It's OK in B&W but colour looks best to me.  Oversaturated?  Who knows? ;-)

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3 hours ago, mikey2000 said:

What a fascinating patch of sky!  Who said it was boring?  It's OK in B&W but colour looks best to me.  Oversaturated?  Who knows? ;-)

Indeed. With the Jellyfish and Lower’s Nebula on either side it’s a lovely area just before galaxy season hits.

I can understand why it could be considered boring. I put of imaging this target as it didn’t look interesting in many images but then I saw someone do a great narrowband and just had to take a look myself. 

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