M51 LRGB

[gorann]

Rodd,

I think you have some magnificent data there but you seem to overdo something in your PI processing. I had a look at Wim's version of your data and compared it to yours and the difference is striking if you zoom in. I know nothing about processing in PI so I cannot advise, but you are loosing the dynamic depth in your data somewhere. Here are screen shots of Wim's and your version.

By the way, are you in the UK as Wim seems to think (when he commented on the weather)? I took for granted that CT meant Connecticut in the US, but maybe there is a CT in the UK.

Tonight the sky seems ok for once here in Sweden and I am shooting away on M95 adn 96.....

[Rodd]

2 minutes ago, gorann said:

Rodd,

I think you have some magnificent data there but you seem to overdo something in your PI processing. I had a look at Wim's version of your data and compared it to yours and the difference is striking if you zoom in. I know nothing about processing in PI so I cannot advise, but you are loosing the dynamic depth in your data somewhere. Here are screen shots of Wim's and your version.

By the way, are you in the UK as Wim seems to think (when he commented on the weather)? I took for granted that CT meant Connecticut in the US, but maybe there is a CT in the UK.

Tonight the sky seems ok for once here in Sweden and I am shooting away on M95 adn 96.....

CT is in the USA--I missed that one.  regarding the images-- I do not feel the data is very good.  There are some examples of M51 collected with far fewer hours that look much better.  For an image with 13 hours, it is strikingly bad.  Not sure why--I was hopeful when I looked at the subs coming off the camera.  Not sure why I punish myself with long hours--weeks due to weather-taking these images when I could get a Tak epsilon and do it in a couple of hours--or a F3-4 Quattro or ASA reflecter.  Anyway--thanks for the input.  I think I need to collect a few more hours of Lum--maybe 20 minute subs to see if I can rescue this image. 

[nucdoc]

1 hour ago, Rodd said:

And here is a touch less saturated. 

 

Wow, I liked the first one, but these reprocessed images are stunning, gives me hope that there is much more I can learn to pull out of my images

 

Mark

[Rodd]

43 minutes ago, nucdoc said:

Wow, I liked the first one, but these reprocessed images are stunning, gives me hope that there is much more I can learn to pull out of my images

 

Mark

Thanks Mark. 

[wimvb]

1 hour ago, Rodd said:

CT is in the USA--I missed that one. 

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

[Rodd]

9 minutes ago, wimvb said:

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

On that you can bet the farm. 

[Rodd]

On ‎3‎/‎25‎/‎2017 at 04:10, Filroden said:

I don't think it's the data. You've captured an amazing amount of detail. Just look how tight the stars are, and the small clusters within the galaxy, and within the core itself.

Have you tried blending the two images together, the one not so stretched and this one? You might find a happy medium between them?

I think I have to come back to this thought. Had you not mentioned the softness I probably wouldn't have zoomed in to see it! I'd have just enjoyed the image for what it was - a great M51 with a bold saturation (which I love but I know is a matter of taste).

 

On ‎3‎/‎25‎/‎2017 at 06:35, wimvb said:

In PixInsight:

Create a copy of the image. Remove all detail. Rename the image 'largescale'. Use pixelmath to subtract from the original, creating a new image called 'smallscale'. Stretch the 'largescale' using any method known by man. Then use pixelmath to add 'largescale' and 'smallscale' into a new image. This is one way to stretch faint signal.

Do this at the very end of your process.

Courtesy of Vicent Peris and RB Andreo.

Gerald Wechselberger has a video tutorial, showing a variation of the technique.

(But you maybe already knew all this)

 

On ‎3‎/‎25‎/‎2017 at 05:06, ollypenrice said:

I think its great. As others have said, I'd reduce the colour saturation myself. I'd also look at the blue balance, whcih I think is a good way over towards cyan, but these are simple adjustments and a matter of taste anyway. More L subs would help pull out the faint extensions. I know you work in LP so this won't be easy. For comparison, Yves and I collected about 22 hours at F6.8 on this target. Much of that time just went into the extensions.

A really nice feature you've caught is the blue tip to the extended spiral arm sometimes known as the Bridge of Light. To me this says the arm is a foreground object and that it is not physically enangled in the smaller galaxy as was once thought. Redhift does put them at different distances.

Olly

 

16 hours ago, gorann said:

Rodd,

I think you have some magnificent data there but you seem to overdo something in your PI processing. I had a look at Wim's version of your data and compared it to yours and the difference is striking if you zoom in. I know nothing about processing in PI so I cannot advise, but you are loosing the dynamic depth in your data somewhere. Here are screen shots of Wim's and your version.

By the way, are you in the UK as Wim seems to think (when he commented on the weather)? I took for granted that CT meant Connecticut in the US, but maybe there is a CT in the UK.

Tonight the sky seems ok for once here in Sweden and I am shooting away on M95 adn 96.....

 

 

What do you think guys--Better?  I really feel that more lum will resolve some of the details better--especially if I go to 20 min (even 15).  No dynamic range lost in this one--not as sharp as I would like when zoomed--but at screen size it looks better to me.

[Filroden]

2 hours ago, Rodd said:

I really feel that more lum will resolve some of the details better--especially if I go to 20 min (even 15).

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.

[ollypenrice]

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

[gorann]

Your new version is clearly the best, with a soft transition between the dust and the surrounding space, and also smooth transitions between the shades in the galaxy when zoomed in. You are clearly on the right track. If you want to increase the sharpness of details in the galaxy, be very selective and use layer masks (or the equivalent in PI) for the parts that can be sharpened.

[Rodd]

2 hours ago, 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

Then how to get sharpness?  Fine details?  There is a lot of fine dust lanes in this galaxy that I am missing--I shot this at a scale of 0.57 arcsec/px but it looks more like 4.5 arcsec/pix

[Rodd]

1 hour ago, gorann said:

Your new version is clearly the best, with a soft transition between the dust and the surrounding space, and also smooth transitions between the shades in the galaxy when zoomed in. You are clearly on the right track. If you want to increase the sharpness of details in the galaxy, be very selective and use layer masks (or the equivalent in PI) for the parts that can be sharpened.

Thanks Goran--this is as far as I can take the data--at least with my current knowledge base.  I guess more lum is not the answer either.  I am looking for sharpness and I get fuzziness.  Could be the seeing, or LP.  I am not convinced of that with this image though.  Focus seemed good--if seeing is so bad, a 2.5-3.0 FWHM can't be all that bad.  In fact, with bad seeing, I would expect to get a higher FWHM.   Maybe M81 will come out better.

Rodd

[gorann]

23 minutes ago, Rodd said:

Thanks Goran--this is as far as I can take the data--at least with my current knowledge base.  I guess more lum is not the answer either.  I am looking for sharpness and I get fuzziness.  Could be the seeing, or LP.  I am not convinced of that with this image though.  Focus seemed good--if seeing is so bad, a 2.5-3.0 FWHM can't be all that bad.  In fact, with bad seeing, I would expect to get a higher FWHM.   Maybe M81 will come out better.

Rodd

Rodd, that last version is a very pretty image!

Regarding M81, I just saw Paddy's resent post at Astrobin. Good for reference, slightly disillusioning for the rest of us (who struggle to get M31 to look like that), but it is from a very very dark place (the DSW obsy) and with a 14.5" RC and done by a pro-processer......

http://www.astrobin.com/288722/

[wimvb]

The newest version looks great. The background seems slightly blue, but that's nitpicking.

 

[Rodd]

24 minutes ago, wimvb said:

The newest version looks great. The background seems slightly blue, but that's nitpicking.

 

Thanks Wim.  No--you are correct.  I saw that after I posted and kicked myself.  I have since neutralized the background so that is fixed.  Thanks for your input.

 

Rodd

[Rodd]

1 hour ago, gorann said:

Rodd, that last version is a very pretty image!

Regarding M81, I just saw Paddy's resent post at Astrobin. Good for reference, slightly disillusioning for the rest of us (who struggle to get M31 to look like that), but it is from a very very dark place (the DSW obsy) and with a 14.5" RC and done by a pro-processer......

http://www.astrobin.com/288722/

Thanks Goran.  That's a hard benchmark to meet!---THE BEST KIND.

Rodd

[Herzy]

I've been trying to mess with his data, but I'm not sure how to turn the gray image labeled RGB into an actual color image. They are both just gray. Am I missing something? I'm using photoshop CC.

[Rodd]

9 hours ago, Herzy said:

I've been trying to mess with his data, but I'm not sure how to turn the gray image labeled RGB into an actual color image. They are both just gray. Am I missing something? I'm using photoshop CC.

Sorry--I am not familiar with PS.  There should be some color whn you combine them, but it will require boosting probably.

Rodd

[johnrt]

Hi Rodd,

I like your last version the best, nice blue colours in the arms, but I find you background too dark, it's not clipped but needs lifting up a touch for me . This LRGB work isn't as easy as the pro's make it look!

[Rodd]

10 minutes ago, johnrt said:

Hi Rodd,

I like your last version the best, nice blue colours in the arms, but I find you background too dark, it's not clipped but needs lifting up a touch for me . This LRGB work isn't as easy as the pro's make it look!

Thanks John--you are right about the background.   Sometimes my LP issue forces me to lower the black point.  I could probably lift it a bit.  I might get some clear hours tonight for some Lum (might try 20 min  or 15 min), and if that does not go well, maybe some Ha.  A few hours of Ha will help this image I think, and will provide for a nice background.  I really want more lum though--it will nag at me forever until i get it.  There is only 9 lum subs in the image as it is.  4-5 more hours might help.

Rodd

[johnrt]

2 minutes ago, Rodd said:

Thanks John--you are right about the background.   Sometimes my LP issue forces me to lower the black point.  I could probably lift it a bit.  I might get some clear hours tonight for some Lum (might try 20 min  or 15 min), and if that does not go well, maybe some Ha.  A few hours of Ha will help this image I think, and will provide for a nice background.  I really want more lum though--it will nag at me forever until i get it.  There is only 9 lum subs in the image as it is.  4-5 more hours might help.

Rodd

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*.  

[Rodd]

8 minutes ago, 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*.  

OK--That's good--10min is a good time anyway.  I should be able to get 24-30 (4-5 hours) if the skies cooperate.  Maybe 36.  If I stick with your ratio--I will need over 100 as I collected 4 hours each of RGB, but I don't think I have the patience for that.  Probably not necessary anyway.  Thanks for the tip.  

[Stub Mandrel]

@RoddI'd be over the moon to capture an image like that, it puts my M51 to shame, and I thought it was one of the best images I've captured.

If you want more definition and sharpness in the detail, have you considered Astra Image? Here's a quick play using a 8-bit version of your image swiped from above.

Sincere apologies if you feel I've ruined all your hard work... I have a tendency to over do the processing.

[Rodd]

56 minutes ago, Stub Mandrel said:

@RoddI'd be over the moon to capture an image like that, it puts my M51 to shame, and I thought it was one of the best images I've captured.

If you want more definition and sharpness in the detail, have you considered Astra Image? Here's a quick play using a 8-bit version of your image swiped from above.

Sincere apologies if you feel I've ruined all your hard work... I have a tendency to over do the processing.

Thanks Stub--wow, that looks good.  Definitely an improvement. I don't mind at all.  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.  Learning new processing software is not something I can handle at present.  I am a slow learner and I am still battling with PI.  I would like to learn some additional things though so i have a more complete tool box.  I do know Nebulosity, but I don't see it being all that much different than PI in results, though it did not take me near as long to learn.  

Rodd

[Rodd]

1 hour ago, Stub Mandrel said:

@RoddI'd be over the moon to capture an image like that, it puts my M51 to shame, and I thought it was one of the best images I've captured.

If you want more definition and sharpness in the detail, have you considered Astra Image? Here's a quick play using a 8-bit version of your image swiped from above.

Sincere apologies if you feel I've ruined all your hard work... I have a tendency to over do the processing.

 

Sorry Neil--I did not see your name before I posted. 

Rodd