NGC 3718

[Rodd]

RGB version with synthetic luminance.  Seeing dropped off a cliff during the blue channel.  The strangest think about LP is that even when the background is clipped, it is still visible.  If I take this one any further it will be clipped.  I badly need a good luminance  - a real luminance

C11Edge with .7x reducer and SI 1600.  About 13.5 hours.  Bin2

[wimvb]

Excellent image, Rodd.

[alan potts]

Fabulous image Rodd, lovely detail.

Alan

[Rodd]

4 hours ago, wimvb said:

Excellent image, Rodd.

Thanks Wim.  I am underwhelmed.  I had an exceedingly rare 4 nights of clear sky with decent seeing (except for the second half of the blue channel).  I had high hopes.  I guess transparency was its usual poor self.  If I didn't know better I would think I picked up a bunch of IFN (NOT!).  Its funny, but the stacks look good.  I couldn't wait to process the data.  I have noticed this before, however--combined data can look worse than the associated stacks.  Maybe a proper luminance will help.  two nights--8-10 hours.  I am in for a week of rain now.  

[Rodd]

4 hours ago, alan potts said:

Fabulous image Rodd, lovely detail.

Alan

Thanks Alan.  I am happy with the resolution--seeing was unusually decent.  Transparency was the issue I think.  You know those nights where you struggle to make out the constellation?

[tomato]

Great image, really sharp. 

[Rodd]

 

2 hours ago, tomato said:

Great image, really sharp. 

 

8 hours ago, alan potts said:

Fabulous image Rodd, lovely detail.

Alan

 

8 hours ago, wimvb said:

Excellent image, Rodd.

 

Thanks Guys--here is a reprocessed image--Bin 2.  More attention to color balance in background. 

 

 

Edited March 22, 2023 by Rodd
wrong image

[ollypenrice]

It's a lovely object and much of the image is right on the money. I can only agree, though, that deep luminance would take it to the next level, letting the faint, extended arms rise more clearly out of the background.

Olly

[Rodd]

29 minutes ago, ollypenrice said:

It's a lovely object and much of the image is right on the money. I can only agree, though, that deep luminance would take it to the next level, letting the faint, extended arms rise more clearly out of the background.

Olly

Thanks Olly.  

[gorann]

Looks really good Rodd with loverly colors, I particularly like the first version but in the second one I can see what I think are deconvolution artifacts (white worms) in the galaxies, especially the bottom one.

Edited March 22, 2023 by gorann

[Rodd]

13 minutes ago, gorann said:

Looks really good Rodd with loverly colors, I particularly like the first version but in the second one I can see what I think are deconvolution artifacts (white worms) in the galaxies, especially the bottom one.

Yeah, maybe the first version is better

 

 

[wimvb]

It seems that you have about the same weather conditions as we have, good seeing, but poor transparency. I agree with Göran re version 2, it seems over-deconvolved, the first image is better. Adding luminance will help, if your conditions allow.

[Rodd]

3 minutes ago, wimvb said:

It seems that you have about the same weather conditions as we have, good seeing, but poor transparency. I agree with Göran re version 2, it seems over-deconvolved, the first image is better. Adding luminance will help, if your conditions allow.

I agree.  I did collect a few lum subs--with the FSQ luminance blows out the sensor pretty fast--I can never use the same exposure time as the other filters.  But I was able to take 120 sec lum subs and they looked good--the FWHM was too high for my liking though, so I packed it in for the night.   Seeing degraded.  For the other filters and 1/2 the blue FWHM was around 2.2.  Not bad.  But it climbed to over 3.5 by the time I got to Lum.  Shame.  But at least I know it will be possible 

[ollypenrice]

1 hour ago, Rodd said:

I agree.  I did collect a few lum subs--with the FSQ luminance blows out the sensor pretty fast--I can never use the same exposure time as the other filters.  But I was able to take 120 sec lum subs and they looked good--the FWHM was too high for my liking though, so I packed it in for the night.   Seeing degraded.  For the other filters and 1/2 the blue FWHM was around 2.2.  Not bad.  But it climbed to over 3.5 by the time I got to Lum.  Shame.  But at least I know it will be possible 

I keep going in these circumstances. My benchmark question is, 'What do I want to do with these captures?' You already have good galaxy core detail, good colour and good stars. All you really need is more signal to separate the faint arms from the background. There is no fine detail in this so do you really need good seeing?

Olly

[Rodd]

54 minutes ago, ollypenrice said:

I keep going in these circumstances. My benchmark question is, 'What do I want to do with these captures?' You already have good galaxy core detail, good colour and good stars. All you really need is more signal to separate the faint arms from the background. There is no fine detail in this so do you really need good seeing?

Olly

Your right. At the time I had not integrated the data and I was not very familiar with the target.  I probably should have kept going.  However, It would be tricky to only use the luminance in the extensions—at least for me…using PI.  I do think the rest of the image will benefit from a good luminance.  I hope to be able to confirm this!

[wimvb]

You can make 2 luminance masters, one with just the best subs for detail (master 1), and one with all the subs for the faint stuff(master 2). You do a Linear Fit on them to get the same brightness. Then you extract layers from both and recombine lower number layers (the fine details) of master 1 with the higher number layers of master 2. This is similar to the technique used here:

https://www.deepskycolors.com/archivo/2010/05/07/multi-scale-Processing--Revealing-very.html

[Rodd]

5 hours ago, wimvb said:

You can make 2 luminance masters, one with just the best subs for detail (master 1), and one with all the subs for the faint stuff(master 2). You do a Linear Fit on them to get the same brightness. Then you extract layers from both and recombine lower number layers (the fine details) of master 1 with the higher number layers of master 2. This is similar to the technique used here:

https://www.deepskycolors.com/archivo/2010/05/07/multi-scale-Processing--Revealing-very.html

Sounds interesting. I think it would still be better to get good luminance data.  It sounds like there is lots of opportunity to screw up with processing. I tell you though, with RC Astro blur exterminator, small stars are not as critical. 

[Rodd]

21 hours ago, ollypenrice said:

I keep going in these circumstances. My benchmark question is, 'What do I want to do with these captures?' You already have good galaxy core detail, good colour and good stars. All you really need is more signal to separate the faint arms from the background. There is no fine detail in this so do you really need good seeing?

Olly

 

23 hours ago, wimvb said:

It seems that you have about the same weather conditions as we have, good seeing, but poor transparency. I agree with Göran re version 2, it seems over-deconvolved, the first image is better. Adding luminance will help, if your conditions allow.

 

On 22/03/2023 at 11:47, gorann said:

Looks really good Rodd with loverly colors, I particularly like the first version but in the second one I can see what I think are deconvolution artifacts (white worms) in the galaxies, especially the bottom one.

 

On 22/03/2023 at 02:32, alan potts said:

Fabulous image Rodd, lovely detail.

Alan

 

Well, I couldn't resist.  I reprocessed the image to what I believe to be better effect.  There are still issues with the background, but I think the faint extensions are better defined and have more color (I did not bump saturation in the extensions).

 

 

Edited March 23, 2023 by Rodd