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M100 - inspired by John

Barry-Wilson

By Barry-Wilson
in Imaging - Deep Sky

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Barry-Wilson

Barry-Wilson

Posted
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Having been inspired by John's beautiful image, I've grabbed 6.7 hours of LRGB over the last 3 nights . . . it is a fascinating area with little fuzzies everywhere.

Hi res here along with a central crop, http://astrob.in/175326/B/.

Details:

  • Avalon Linear FR
  • WO FLT132, 3.5"FT & WO reducer at F5.6
  • Atik 460EX
  • Baader filters
  • SGP for capture and PI for processing.

Thanks for looking.  Crop below.

Barry

post-28392-0-66822200-1429825217_thumb.j

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Scott

Scott

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Lovely image this..... so refreshing when you see an image thats not been processed to within an inch of its live. Loving all those faint (and not so faint) fuzzies too.

Thanks for sharing it

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Barry-Wilson

Barry-Wilson

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Thank you all very much.

The optics are excellent and it is a pleasure to use, although it does have heavy chunks of glass at each end, so has quite a moment-arm on the mount.  I have been musing over the AP 130mm F6 Starfire EDF on AB&S, I can't gauge how much better the optics would be in contrast to the FLT132; weighed against a premium price no doubt.  Anyone any experience of this scope?

I've just fitted an OAG as an experiment to help imaging at its native FL (I have a secondhand TMB flattener bought from Gary Beal the imager from NZ); hope I don't set myself an exhaustive task!  Using my 460EX I get 1"/px.

Barry

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Big Jim Slade

Big Jim Slade

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Really Nice. To me it seems you've nailed the contrast - the background is only just black enough, which of course means all the little DSOs are visible. Well done.

The optics are excellent and it is a pleasure to use, although it does have heavy chunks of glass at each end, so has quite a moment-arm on the mount.  I have been musing over the AP 130mm F6 Starfire EDF on AB&S, I can't gauge how much better the optics would be in contrast to the FLT132; weighed against a premium price no doubt.  Anyone any experience of this scope?

I have no experience of one, but if you've got the budget, given the reputation it's got to be worth a punt, right? Even if you let it go, you're unlikely to loose much on it.

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johnrt

johnrt

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That's great Barry, and I'm made up I've inspred someone else to produce an image of M100 - it's such a great field of view I really don't know why it isn't a more popular target. Great processing and it looks like you have a little more control on the core on M100 than me, could be the added 300sec subs that did the trick.

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Barry-Wilson

Barry-Wilson

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Thank you all.

Really Nice. To me it seems you've nailed the contrast - the background is only just black enough, which of course means all the little DSOs are visible. Well done.

I have no experience of one, but if you've got the budget, given the reputation it's got to be worth a punt, right? Even if you let it go, you're unlikely to loose much on it.

 Too many competing demands on my budget - but it's nice to dream.  I also adjusted the blackpoint and updated the image on Astrobin - a day of two of distance between finishing can often reveal the need for small adjustments - and you're right that a tad darker in the background has helped.

This is a cracking image with delicate processing - very nice indeed


Sent from my iPhone from somewhere dark .....

Thanks Steve, that means a lot coming from you :grin: .

That's great Barry, and I'm made up I've inspred someone else to produce an image of M100 - it's such a great field of view I really don't know why it isn't a more popular target. Great processing and it looks like you have a little more control on the core on M100 than me, could be the added 300sec subs that did the trick.

 Yes, after examining the stack of 600s subs I added the 300s subs to my sequence to see what would be revealed.  Where I lost out I think is in the delicate blue of the spiral arms which you have captured.  I only have the faintest hint, any more saturation and the image would be ruined.  I ran out of time to collect more RGB data as the moon was making its presence felt.  Thanks for your praise John.

Hi Barry

That's certainly a fine image. I agree with Auspom, the processing seems delicate and unforced. I'm interested to know what PI processing steps you made to achieve this excellent result.

Regards

John

My processing workflow is similar to yours but there are some crucial differences from your list (it may simply be that your list is an abbreviated version).  Of course the workflow is an evolving process as I continue to learn and develop a style and feelilng for my targets.

  1. I carry out image integration of the registered subs and do not use the the master - it gives a better result.  (Use cosmetic correction in the BPP).
  2. I save a new instance of the dynamic crop to apply to all of the subs - then crop before DBE - it is critical for effective gradient removal.
  3. When the RGB is combined, I use RGB working space to even out the the 3 channels, specifically lowering the green.
  4. Background neutralisation before colour calibration - this can take some experimentation to get the right settings - eg whether to use previews for nackground and/or white references.  The size and position of the white refernce preview can have a surprising effect on the end result.
  5. I use the repaired HSV separation script to improve star colouring through to the cores; then re-combine the RGB channels using HSV.
  6. I stretch the RGB with the masked stretch process - much beter control of colours and star bloat.  I will also clone this and use exponential transform, sometimes using pixelmath to combiine the two results (Rick Stevenson's PS combination scripts can be useful here)
  7. I use deconvolution on my Lum subs, saving the star mask for future use in star reduction and de-saturation.  I find in my image scales that this really helps elicit small structure detail (be gentle though you can easily overdo this).
  8. I will produce a couple of Lum stretches - masked stretch, plain HT stretch (to differing levels) - and then combine with pixelmath.
  9. HDR multiscale (use star mask as well lum mask).  I sometimes produce 2 or 3 versions and combine with pixelmath.
  10. Sharpen using atrous wavelets in the first 2 or 3 layers.
  11. Use LRGBcombination, with a small boost to saturation.
  12. Then its down to whatever the subject of the image needs to further enhance the final result: SCNR (invariably this is used to shed the green tinge), local histogram equilisation (often with two different levels at low percentages), noise reduction (ACDNR and TGVDenoise - gentle here too), dark structure enhance, large scale structure enhance, curves, saturation boosts, further histogram adjustments, more sharpening, star reduction etc.  These will require different sorts of masks and in different combinations.  I'm tending to use low settings now and more iterations rather than larger transistions between processes.

I'm happy to help with pointers if you want to PM me, or start another post so others can follow and chip in, as there are other regular and skillful PI users who might give away top tips!

 Barry

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