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M51 LRGB

Rodd

By Rodd
in Imaging - Deep Sky

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Stub Mandrel

Stub Mandrel

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Just now, Rodd said:

I have heard of astra image.  I can't remember if that's the one I downloaded for free a while back, of if that was another one.  If it cost I didn't download it.  I didn't try it, what ever it was.

It's about £40.

Very easy to use, basically for each process you get a series of sliders and preview box at 1:1 pixel zoom, just play with the sliders until you get a better result.

What I did was take a copy, and applied  deconvolution (Lucy Richardson, Lorentzian, kernel size 1.3, strength 1.3 is always a good place to start).

This made it crisper, but because I was using a screen grab it created a few isolated dark pixels, I hit these with denoise at a low setting.

Finally I used contrast enhancement and just played with the small and medium sliders on the 'mid tones' to make it look just a bit too startling.

I then overlayed the result back onto the original in PS, just masked to the galaxy (as the stars looked too sharp) and used about 70% transparency to take the unnatural edges off.

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Herzy

Herzy

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Ok, I figured out the color thing. I'm probably repeating others, but prestretched data is hard to work with. I had to work on taming more than anything else. I also tried to keep a soft feel. A lot of the images in here really bring out the detail, but they look too sharpened. I particularly like wim's attempt. He managed to bring out a lot of detail without over-sharpening.

M42 Final (data).png

Core close up.png

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Rodd

Rodd

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35 minutes ago, Herzy said:

Ok, I figured out the color thing. I'm probably repeating others, but prestretched data is hard to work with. I had to work on taming more than anything else. I also tried to keep a soft feel. A lot of the images in here really bring out the detail, but they look too sharpened. I particularly like wim's attempt. He managed to bring out a lot of detail without over-sharpening.

M42 Final (data).png

Core close up.png

:hello2:  That's the one.  Very nice.  Looks "real". Detailed, yet soft, yet sharp.  5-6 hours of lum and a few Ha will really make this image come to life (perhaps not in my hands!) .  Thanks Herzy.   

Rodd

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Rodd

Rodd

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On ‎3‎/‎27‎/‎2017 at 14:31, ollypenrice said:

More lum won't be about sharpness, it will be about pulling out the extensions.

I prefer the reduced saturation and new colour balance.

Olly

 

On ‎3‎/‎26‎/‎2017 at 19:52, wimvb said:

My bad. But the (poor) weather seems global.

 

On ‎3‎/‎29‎/‎2017 at 09:30, johnrt said:

Yes a successful LRGB image is all about the quality of the luminance. For example, if I put together a 20 hour image then it will consist of something like 14 hours luminance and 6 hours RGB (2 hours per filter). I routinely shoot 10 minute Luminance and 5 minute (bin 2) RGB. I would not worry about going longer on your Lum subs as they are very susceptible to light pollution, gradients etc etc, just lots more of them, and I mean *LOTS*. :) 

 

On ‎3‎/‎27‎/‎2017 at 13:19, Filroden said:

When I looked at your L and RGB files I was hard pressed to see that your L data would add anything (the RGB was so good). If your issue is seeing/moisture in the atmosphere then longer subs might make things even softer. 

Id be tempted to track back and stretch a single sub. If that looks good I'd make sure all the subs are similar. I find the SubFrameSelector script useful for detecting issues...subs with excessive FWHM or eccentricity, subs with too high a S/N compared to the rest (indicating faint clouds), etc.

Well--here is with the addition of 5 more hours of luminance (10 min subs).   The night was great and the data was the best of any of the filters.  I think 20 min subs would have been super--the night was darker than usual and I was shooting at high declination.

LRGB-NoMD-L37-3.thumb.jpg.9e95606a7061cb9124c6a1e5105929de.jpg

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wimvb

wimvb

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Excellent result, well worth the extra time. Did you add the extra luminance to the old data, or use it by itself. Since imaging conditions have changed between then and now, you could consider using just the new data. Rgb is much less critical.

 

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Rodd

Rodd

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7 hours ago, wimvb said:

Excellent result, well worth the extra time. Did you add the extra luminance to the old data, or use it by itself. Since imaging conditions have changed between then and now, you could consider using just the new data. Rgb is much less critical.

 

Thanks Wim--I reprocessed everything from scratch using the old and new luminance data.  I like to register all subs in all channels to the sub that has the lowest FWHM and eccentricity (FWHM usually taking precedence unless the eccentricity is way off).  It just so happens that that was one of the old Lum subs.  I think it may be a tad over saturated, and I should have masked out the background when I applied noise reduction (looks a bit mottled in full resolution mode).  But it beats my previous attempts for sure 

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Rodd

Rodd

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5 hours ago, ollypenrice said:

Now you have it nailed. That's a gorgeous M51, delicately processsed yet bold. Superb background sky and stars. The lot. Staying power always wins in this game.

Olly

Thanks Olly.  A tad over saturated?  In full image-zoomed-mode the background appears a bit mottled (i should have masked the background before apply NR I guess.) .  I am wondering if it would benefit from a few hours of 30 min Ha subs.

Rodd

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Rodd

Rodd

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5 hours ago, swag72 said:

That final M51 is very nice indeed :)

Thanks Sara!  I am wondering if F10 instead of F7 (take off the reducer) would bring some of the fine details this galaxy has within range of a 1:1 scale (full image zoom mode is tough to process for with BB data for me).  I have not yet tried to image at F10 with C11Edge

Rodd

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ollypenrice

ollypenrice

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6 minutes ago, Rodd said:

Thanks Olly.  A tad over saturated?  In full image-zoomed-mode the background appears a bit mottled (i should have masked the background before apply NR I guess.) .  I am wondering if it would benefit from a few hours of 30 min Ha subs.

Rodd

I like it as is. ButI do like strong colour.

Olly

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Rodd

Rodd

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5 hours ago, Stub Mandrel said:

There are two extra 'jets' on either side of the smaller galaxy that have now become visible on my monitor.

Excellent.

Yes--these were there in the previous image, but bringing them out required too hard of a stretch and the rest of the image suffered.  I have a feeling there are loads more details in this galaxy waiting to shine forth.

Rodd

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Rodd

Rodd

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4 hours ago, gorann said:

You have done it Rodd, produced a magnificent M51 in LRGB! Congratulations!

Thanks Goran!  Looking forward to adding some Ha.  I will reprocess from scratch if I manage to collect Ha, that way I won't ruin what I have!

Rodd

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johnrt

johnrt

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1 hour ago, Rodd said:

Thanks John.  Ha?  This galaxy has allot of it.

Nah! Adding Ha to galaxy images is just for the "Fancy Dans". 

In all seriousness looks like you have picked up plenty already, not sure how much it would add to the image. 

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