Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

Nebulousity around M45 - 7 hours data


tooth_dr

Recommended Posts

2 minutes ago, tooth_dr said:

The ability to judge by eye is something I will just have to work on!

Yes, this is how i process. I don't have a workflow. I try to let the data tell me where to go next. Usually when i make a change to an image i do so as a duplicate layer and then adjust the opacity once i'm happy the change hasn't created any unwanted effects. I often blend it back in to the original at 50%.

The best piece of advice i ever got was to let the image sit for a while, go away and do something else for a few hours, days even and when i return if the image still looks good then i post it. Amazing how a walk can help you gain some perspective on an image. Usually i end up pulling an image back a bit as i often over do things.

Link to comment
Share on other sites

  • Replies 50
  • Created
  • Last Reply
39 minutes ago, Allinthehead said:

Yes, this is how i process. I don't have a workflow. I try to let the data tell me where to go next. Usually when i make a change to an image i do so as a duplicate layer and then adjust the opacity once i'm happy the change hasn't created any unwanted effects. I often blend it back in to the original at 50%.

The best piece of advice i ever got was to let the image sit for a while, go away and do something else for a few hours, days even and when i return if the image still looks good then i post it. Amazing how a walk can help you gain some perspective on an image. Usually i end up pulling an image back a bit as i often over do things.

Thanks Richard. I use layers now too and blend in at what % looks ok! Less is more and I can often over do them too. Looking at my M45 now, the back ground is very brown but at the time thought I had addressed it.  

Link to comment
Share on other sites

On 10/11/2018 at 20:36, TareqPhoto said:

Beautiful, I really wish I can have same like this results in my LP area, who knows, you did a great job, this target was my first ever target to view in the sky when I started last year, because of it I got deeper into astronomy.

Thanks TQ.  I'm getting better all the time.  Like you M45 got me hooked (along with a few others), this was my first M45 image.

M45editsmooth.jpg

 

 

 

Link to comment
Share on other sites

Hi

I've tried to follow the advice on this thread.  Some colour balancing, HLVG (using color later). I've selectively sharpened, selectively noise reduced, and then combined in layers, with bluring and saturation adjustments.  I stayed away from curves and levels adjustments, until the end just to remove dead space at the bottom of the histogram.  I used the data with the DDP stretch out of APP.

What do you think?

 

 

 

 

Aligned_processed_LUM_RGB.jpg

Link to comment
Share on other sites

Colour balance looks much better!

The image appears darker at center and brighter at margins (left and right sides), perhaps you can improve that.

Another thing that can improve sometimes is to increase the level of very dark pixels. For this, you can duplicate the image, add a grayscale mask, invert it, stretch it very, very hard (so that the dark pixels inverted become white and the background around it, inverted, is dark), then increase the black point. You will get a more uniform background this way. But, beforehand, I'd say you should tame down the margins so the effect would apply uniformly.

Link to comment
Share on other sites

20 minutes ago, moise212 said:

Colour balance looks much better!

The image appears darker at center and brighter at margins (left and right sides), perhaps you can improve that.

Another thing that can improve sometimes is to increase the level of very dark pixels. For this, you can duplicate the image, add a grayscale mask, invert it, stretch it very, very hard (so that the dark pixels inverted become white and the background around it, inverted, is dark), then increase the black point. You will get a more uniform background this way. But, beforehand, I'd say you should tame down the margins so the effect would apply uniformly.

Thanks for this.  I thought the first one looked too dark at the edges so I did a gradient reduction.  I kinda thought I’d overdone it but I ignored it. Mistake indeed!

Back to the start ?

Link to comment
Share on other sites

3 minutes ago, tooth_dr said:

Thanks for this.  I thought the first one looked too dark at the edges so I did a gradient reduction.  I kinda thought I’d overdone it but I ignored it. Mistake indeed!

Back to the start ?

I cannot tell you how much easier is now that I'm quite familiar with PixInsight. In the beginning I didn't want to learn another tool, but now I feel sorry I didn't give it a shot earlier. Manipulating an image in the linear phase has some real benefits.

Anyway, you will do the gradient removal in the linear phase in APP too. My suggestion is to spend time to get the best of the image in every phase and save it when you're happy. Then continue.

Link to comment
Share on other sites

15 hours ago, tooth_dr said:

Hi

I've tried to follow the advice on this thread.  Some colour balancing, HLVG (using color later). I've selectively sharpened, selectively noise reduced, and then combined in layers, with bluring and saturation adjustments.  I stayed away from curves and levels adjustments, until the end just to remove dead space at the bottom of the histogram.  I used the data with the DDP stretch out of APP.

What do you think?

 

 

 

 

Aligned_processed_LUM_RGB.jpg

I agree the colour balance definitely looks better. Alex is right about the edges though. I don't think you needed to run the gradient reduction again, so you might have to go back to the previous stage.

Did you try making a super luminance before merging it with the colour data? You really should, it could potentially really increase the overall SNR (I notice the noise is starting to creep up a bit in places). Perhaps it's been stretched a little too much? A neat trick to dial it back a bit is to try the following:

Copy the Image. Convert it to LAB color space, then paste the image into the 'Lightness' channel. Then convert it back to RGB mode. This has the effect of darkening and smoothing the image, and is always worth trying out on every image just to see if it improves it.

If you're unsure about how to create the super luminance, it might be an idea to share the data and let others have a go at combining them. If the outcome is good then one of us could walk you through how it was achieved.

Link to comment
Share on other sites

On ‎10‎/‎11‎/‎2018 at 04:05, Xiga said:

Just remembered something else. At this point you have plenty of colour data. If you want the image to be less noisy then what you really need is more luminance. The good news is, you actually have lot more luminance than you realise.

You can convert the DSLR data to grayscale, then create a super luminance from both it and the 383L+ data, by layering the DSLR data on top in Screen blend mode at the appropriate opacity. This could really boost your Luminance before combining it with the DSLR colour data. 

Ps - You should check out Scott Rosen's DSLR LLRGB approach in the video below. Not all of it will necessarily apply to you, but a lot of it will, and wouldn't you know it it's also of M45 too! ? It's over 2 hrs long, but we'll worth it. 

http://www.astronomersdoitinthedark.com/dslr_llrgb_tutorial.php

 

Just realised I hadn't copied the link correctly.

Have edited the original post so it should be working now.

Link to comment
Share on other sites

1 hour ago, Xiga said:

I agree the colour balance definitely looks better. Alex is right about the edges though. I don't think you needed to run the gradient reduction again, so you might have to go back to the previous stage.

Did you try making a super luminance before merging it with the colour data? You really should, it could potentially really increase the overall SNR (I notice the noise is starting to creep up a bit in places). Perhaps it's been stretched a little too much? A neat trick to dial it back a bit is to try the following:

Copy the Image. Convert it to LAB color space, then paste the image into the 'Lightness' channel. Then convert it back to RGB mode. This has the effect of darkening and smoothing the image, and is always worth trying out on every image just to see if it improves it.

If you're unsure about how to create the super luminance, it might be an idea to share the data and let others have a go at combining them. If the outcome is good then one of us could walk you through how it was achieved.

Hi Ciaran!  Thanks again.  So I went back to the start, did only a little gradient removal to get rid of dark corners, I worked through the process as previous with the layer masks, and added the DSLR data the way you suggested previously also.   I did the LAB bit above using the lightness channel, and converted back to RGB - is the colour supposed to come back or stay greyscale?  When I converted it back to RGB colour it remained grey?  It's getting harder to follow that's for sure but this is the first image I've sat back and thought it was quite amazing.  Thanks for the tips, you made it happen.

 

Adam.

 

 

 

 

 

 

Aligned_processed_LUM_RGB_lower_grad_xt.jpg

Link to comment
Share on other sites

33 minutes ago, tooth_dr said:

Hi Ciaran!  Thanks again.  So I went back to the start, did only a little gradient removal to get rid of dark corners, I worked through the process as previous with the layer masks, and added the DSLR data the way you suggested previously also.   I did the LAB bit above using the lightness channel, and converted back to RGB - is the colour supposed to come back or stay greyscale?  When I converted it back to RGB colour it remained grey?  It's getting harder to follow that's for sure but this is the first image I've sat back and thought it was quite amazing.  Thanks for the tips, you made it happen.

 

Adam.

 

 

 

 

 

 

Aligned_processed_LUM_RGB_lower_grad_xt.jpg

Much better

Link to comment
Share on other sites

2 hours ago, tooth_dr said:

Hi Ciaran!  Thanks again.  So I went back to the start, did only a little gradient removal to get rid of dark corners, I worked through the process as previous with the layer masks, and added the DSLR data the way you suggested previously also.   I did the LAB bit above using the lightness channel, and converted back to RGB - is the colour supposed to come back or stay greyscale?  When I converted it back to RGB colour it remained grey?  It's getting harder to follow that's for sure but this is the first image I've sat back and thought it was quite amazing.  Thanks for the tips, you made it happen.

 

Adam.

 

 

 

 

 

 

Aligned_processed_LUM_RGB_lower_grad_xt.jpg

Much better indeed! 

Something you need to watch out for though, keep an eye on your Histogram (i keep mine open all the time). I opened your image and checked the histogram, and the Blue channel is clipped at the white end ( see pic below).

Capture.thumb.JPG.8a46d8256fb5a7458948499fb1fea9ee.JPG

As for the 'LAB mode trick', you must not have done it right. Let me explain in a bit more detail:

Duplicate your layer and copy the image (Ctrl-C). 

Now do Image->Mode->Lab Color. Don't Flatten when asked! 

On the new Layer, click on the Channels tab and then select the Lightness Channel. Now paste in the image (Ctrl-V). What you are now doing is compressing the entire Dynamic Range of the image into just the Lightness Channel, and ignoring the a and b Color channels. 

Finally convert back to RGB mode (again, don't flatten). 

You can see the outcome below, along with the histogram, which now looks much better:

Capture2.thumb.JPG.9f75987236d2a5d3b2e238b03a793401.JPG

As you can see, it has also pegged back the stretch somewhat, so if you feel it needs it you can always try pushing it a bit further with some micro-curves. 

A couple of ideas for some final tweaks:

1. Increasing the Saturation of the Yellows, to bring out the yellow star colours a bit more. Or alternatively, run Carboni's Increase Star Colors routine and use a Layer Mask to only apply it to the yellow stars. 

2. Increasing the Vibrance. I find large colourful objects tend to respond well to increased Vibrance moreso than Saturation. 

3. There is a little bit of colour noise running throughout the background. Not much, but it's noticeable at close range. A quick blast of Color Noise Reduction (about 20%) in the Camera Raw Filter should sort that out. And to eliminate any risk of the filter removing colour from any tiny stars (which it can do) you could firstly just select the stars, expand by 4 pixels, feather it by 2, and then do Select-Inverse. Now when you use the filter the stars will be excluded. 

Link to comment
Share on other sites

37 minutes ago, Xiga said:

Much better indeed! 

Something you need to watch out for though, keep an eye on your Histogram (i keep mine open all the time). I opened your image and checked the histogram, and the Blue channel is clipped at the white end ( see pic below).

Capture.thumb.JPG.8a46d8256fb5a7458948499fb1fea9ee.JPG

As for the 'LAB mode trick', you must not have done it right. Let me explain in a bit more detail:

Duplicate your layer and copy the image (Ctrl-C). 

Now do Image->Mode->Lab Color. Don't Flatten when asked! 

On the new Layer, click on the Channels tab and then select the Lightness Channel. Now paste in the image (Ctrl-V). What you are now doing is compressing the entire Dynamic Range of the image into just the Lightness Channel, and ignoring the a and b Color channels. 

Finally convert back to RGB mode (again, don't flatten). 

You can see the outcome below, along with the histogram, which now looks much better:

Capture2.thumb.JPG.9f75987236d2a5d3b2e238b03a793401.JPG

As you can see, it has also pegged back the stretch somewhat, so if you feel it needs it you can always try pushing it a bit further with some micro-curves. 

A couple of ideas for some final tweaks:

1. Increasing the Saturation of the Yellows, to bring out the yellow star colours a bit more. Or alternatively, run Carboni's Increase Star Colors routine and use a Layer Mask to only apply it to the yellow stars. 

2. Increasing the Vibrance. I find large colourful objects tend to respond well to increased Vibrance moreso than Saturation. 

3. There is a little bit of colour noise running throughout the background. Not much, but it's noticeable at close range. A quick blast of Color Noise Reduction (about 20%) in the Camera Raw Filter should sort that out. And to eliminate any risk of the filter removing colour from any tiny stars (which it can do) you could firstly just select the stars, expand by 4 pixels, feather it by 2, and then do Select-Inverse. Now when you use the filter the stars will be excluded. 

Brilliant Ciarán. This thread should be stickied ?

Link to comment
Share on other sites

3 hours ago, RayD said:

Superb, Adam.  Really very well done indeed.

Hats off, Sir!

Cheers Ray, I’ve been guided so much by the SGL members. I feel like Ive moved up a league and the investment in time and equipment has paid off. 

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.