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M81 and M82 IFN LHaRGB


Steve 1962
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It's been a while since I've done much, but I've finally managed to get somewhere with this.

post-6387-0-10193200-1429809633_thumb.jp

The full size is here - https://www.flickr.com/photos/perrybarn/16626383073/sizes/l

This is 28 hrs and 20 mins total exposure time made up of 52x900s Lum, 14x600s Red, 18x600s Green, 15x600 Blue and 15 x 30min Ha. 

The background is noisy, but I left it this way to try to touch the IFN as little as possible. I've got to the point that I've said to myself "Hey - it's noise, but at least it's honest noise" - this stuff if faint! - especially for a 4" scope under UK skies.

Here's a much less aggressive version which still shows sone nice IFN detail:

post-6387-0-80675000-1429810919_thumb.jp

Time to move on I think!

Thanks for looking.

Steve

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I do prefer the first for the amount of flux, I think you could get somewhere inbetween with some very carfull masking and subtle noise reduction.

Edit:

Id be inclined to proces the galaxys seperate from the flux then layer them in PS

Edited by Earl
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Thanks everyone...delighted you ike it!

Earl - this was done in PI. The way I processed it was to produce a conventional Ha/R,G,B image with a seperate Lum.I got the RGB image to where I wanted the colours and then processed the L by getting the galaxies to where I wanted them range -wise. I then used a seemigly never ending string of successive masks (range and star masks plus some pixel mathS - NOT math!!) to hold the stars and galaxies back while I pushed the dark stuff until it nearly broke.

I got as far as I could with the Lum and only then added it to the HaRGB. Then did some more curves, histogram and noise stuff to "finish" it off.

I'll probably have a another go at some point but I've been looking at this since January - so I need a break. Off to see how the needle looks I think!

Steve

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Well done indeed. For me the problem with the first one isn't noise, it's colour balance. The green channel is, I think, too high and gives a 'green rinse' across the board. I'd give it a zap with SCNR Green or Hasta La Vista Green.

This is a tough challenge. I don't think aperture comes into it very much but dark sky plays a huge role in making it difficult rather than infernal! This is a fine Flux.

Olly

Edit; A quick test would be to put the first one over the second one in Ps as Layers and choose Blend Mode Luminosity. Or you could put the second one over the first in Blend Mode Colour. That way you might end up with the best of both.

Edited by ollypenrice
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Agh!

Olly - as always it's the colour balance that trips me up!! ..and it's always you who points it out!

Here's a version of the deep one hit with SNCR in a couple of steps...

post-6387-0-39004300-1429820266_thumb.jp

..and heres a "shallow" over "deep" colour blended....

post-6387-0-40358600-1429820371_thumb.jp

...and here's a "deep" over "shallow" luminosity blended.....

post-6387-0-03948300-1429820422_thumb.jp

They all look better than the original to me - but the second is my current favourite.

Thanks for your tips Olly. :headbang:  :headbang:   

Steve

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Just as I clicked submit on my reply, I caught a glimpse of Olly's tag line "Isn't it great that amateurs can get so close to the universe?"

  Yes - I absolutely agree Olly - we amateurs are debating imaging the IFN from a back garden in Somerset.

This is stuff that was only really discovered about ten years ago.

Great? Yes.  

Mind Blowing? Absolutely!

Steve

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You've achieved a great result Steve from all of your hard work: the IFN really pops.

I'd encourage you to try some ACDNR (try: set with a high St Dev (I use 9.0), a low amount 0.3, 6 iterations, robustness 'morphological median', set your lightness mask from your preview (in both lightness and chrominance), replicate the settings for Chrominance & Lightness, apply and gauge your result).  Adjust your black point slightly with HT afterwards.  One last step and it'll really shine.

Barry

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That's an absolute gem Steve, lots of work both in terms of capture and processing has gone into this. The swirls of IFN around the galaxies are really nice and the final colour balance you have here looks in the sweet spot - great result, get it submitted to Astronomy Now!

Martin

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Its looking great, the only thing I personally would try to do is fix the stars now as they do have a fair bit of haloing going on and the brighter ones have blown out cores and are white, have you tried the halo tool in PI, its good onc you get to grips with it, its best done in small steps.

edit far easier said than done though :)

Edited by Earl
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Thanks Olly, Martin and Earl

Good idea Martin - I need all the £10's that I can muster in order to Mrs L happy!!

Earl - I've have a go at star reduction / halos and report back  :icon_salut:

Cheers

Steve

Wish I was gathering data atm my focuser is in Hereford now, im just waiting for the paperwork to pay the customs.......

Star reduction helps a fair bit with this sort of thing, however it might start to mess with the flux on an image like this as it might put holes in it,

Personally star reduction is the thing i do after my main stretch and before stretched noise reduction routines, to nip it in the bud so to speak on any other stretching done, Im yet to work out how to do a full star removal and then process them totally independantly of the background as I feel especially with this sort of data is the best way to do it. then drop the starts back into a processed background.

Now it could be argued that im trying to make a pretty picture rather than work with the captured data, well that works for me as both styles are vaiid in my book.

roll on next week when I hope to install all the goodies, and then have the cloud roll in LOL, need to redo PA first as im sure it will be out.... round and round and round LOL

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Wonderful image Steve.

I'm still on the free 60day trial of PixInsight so you guys are mostly speaking a foreign language but the results are great. So much to learn!

Well done on a great image.

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Thanks Paul, Barry and Mike 

 Im yet to work out how to do a full star removal and then process them totally independantly of the background as I feel especially with this sort of data is the best way to do it. then drop the starts back into a processed background.

 

Now it could be argued that im trying to make a pretty picture rather than work with the captured data, well that works for me as both styles are vaiid in my book.

My sentiments exactly Earl - I'd like to get rid of these stars altogether, drag out Galaxies to a nice level and lock them in place, then really stretch out the IFN, do Barry's SD9 noise reduction on that, add back the galaxies and finally put RGB stars back in. SImples!!

By the way - I hear you're going from your stock Tak focusser to an FT - can I ask why? I'm certainly very interested to hear how you on with it.

ATB

Steve

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I'm still on the free 60day trial of PixInsight so you guys are mostly speaking a foreign language but the results are great. So much to learn!

Mike - make sure you watch Harry's Page's PI videos....and keep playing with. I think it's a fantastic piece of software.

Steve

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The reason for my Focuser upgrade is down to Automation, I have found the generic, Robofocus comp, stepper unreliable and dont like that whole bolt on approach, so decided to get the FT as it has a real dedicated upgrade and the version of the focuser is dedicated to deal with the 106 back focus issues.

In an ideal world I would of put a FLI Atlas on with the OTA adapter, however HOW MUCH !!! its cost me ove a grand for the FT setup, FLI would be over 2k

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Thanks for the great feedback Sarah, Colin, Martyn and Paul!

Earl - looking forward to seeing how you get on with your new focuser. :shocked:  :Envy:  :eek:

It's just started to rain here now so I'm trying to remove the star bloat from the image. :confused:

Steve

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