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Getting Colour into Images


Marky1973
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Got out last night to have a play and had a go at the Soul Nebula to test out my modded 100d and to push up my subs to 7 minutes just to see if I could get guiding at that length.

I only have about 1hr 40mins of lights (plus darks, bias, flats) so I know that I am not going to end up with the greatest image. However, with a quick fiddle in PS I managed to get the following (apologies for the poor framing!  :grin: )

post-35662-0-19680900-1443037772_thumb.j

I have some more tutorials to work through and am sure I can get more out of it. However, the big thing for me in pretty much every image I have been working on is colour. I find it really hard to pull the colour out of any image after stacking. I would have thought the 7 minute, ISO800 subs would have a fair amount of colour in them, I just seem to struggle to pull it out.

Stacked in DSS, this is the finished product.

post-35662-0-66917500-1443038009_thumb.j

I may be missing something by the RGB curves seem very narrow. I never seem to get anything wider than a few pixels, which I guess gives an indication as to why I struggle to find the colour in the image.

Or am I wrong? Does the width not matter? Or am I missing a setting in DSS? I have tried a number of different ways to stack, changing settings around Dark Optimisation, RGB alignment, but nothing seems to make a difference. I have tried using different WB settings in the RAW settings, as well as changing the Bayer Matrix Transformation settings, but still seem to end up with thin curves.

Any ideas, or am I just going to have to keep going and get more subs?

Cheers!

Mark

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Hi Freddie. Yeah, I should have said that I usually align the channels and adjust slightly in DSS to start and then move on to PS. Essentially I just did a few iterations of levels and curves to stretch the histogram and upped the saturation slightly. I appreciate I have a lot of learning to do with processing, I  am just wondering if I am doing something wrong with DSS that means the curves are narrow and I am missing out on colour or whether I am asking too much for only 100 minutes of subs.

At least my guiding seems to be working! :-)

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I would say the DSS output is what would be expected. However, the person who created DSS says no adjustments made in DSS should be applied to the saved stack. he says all processing should be in PS or similar, the adjustments are just there so that you can have a quick look at what the data can produce.

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Yeah, I have read that. I do try both, using the AUTO Tiff and saving the DSS output at a 32bit Tiff for PS - results seem to be much the same, maybe a little harder to process without any changes in DSS....which, I guess, suggests I just need to get stuck into more processing tutorials! Cheers Freddie!

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Hi Geordie - yeah did that as well, both within DSS before and in PS. I guess I may just have unrealistic expectations of what I should be seeing and need to be getting more data. If tonight stays clear, perhaps I can have another go and add more data to the image. Thanks, Mark.

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Hi Marky,

Let me preface my comments by saying that I'm very new to astro imaging and certainly no PS expert, mostly doddling along on a need to learn basis.

I downloaded your <500kb image to have a play with and found I could really bump the colours using CS6's Image/Adjustments/Selective Colour tool which I find I can get better individual colour adjustment with than Chanel Mixer or Colour Balance. But then I don't really know what I'm doing.  :confused:

I wont post the result of my fiddle as at this stage I don't really know what a good astro shot should look like, and PP is also very subjective.

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Your levels in DSS look to be too far to the right to me. I generally aim to get them lined up about a third of the way across and then up the saturation to about 24% or so. I use a modded 1200d and got more colour out with less subs on the Heart which is similar. I then up them again in levels and curves.

Peter

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Your levels in DSS look to be too far to the right to me. I generally aim to get them lined up about a third of the way across and then up the saturation to about 24% or so. I use a modded 1200d and got more colour out with less subs on the Heart which is similar. I then up them again in levels and curves.

Peter

Yes, way to high,

Make sure the RGB levels are linked and pull them back under the curve so the steepest

part of the curve goes up through the bottom third of the RGB.

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That's about the same as my first (and only, so far) attempt at Soul with my modded camera (attached). As has been said, selective colour does brighten it up but beware of noise. Did you use a filter? I still find a UHC filter is needed on most nebulas. Also, the moon was in play last night, depending on the time you imaged. Tonight, it will ruin images up to about 2.00am. If I can't sleep I might do some as the the cloud forecast is good.  :smiley:

Think the moon affected this one as well, if I remember rightly...

post-35654-0-43003800-1443083053_thumb.j

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Colour can be tricky. Looking at this I'd say...

1) You have gradients which need tackling. In Ps you can use the Eyedropper tool in Colour Sampler mode to measure your background sky in all channels. I like 23/23/23 in R,G and B. The best gradient fix is DBE in Pixinsight but if you prefer you could buy Gradient Xterminator from Russ Croman. Not as good as DBE but good.

2) Like most of us you are having problems with green noise. In PI, SCNR Green will zap that. In Ps you could get the free Hasta La Vista green from Rogelio's Deep Sky COlors website.

3) Once the colours are right but not sufficiently intense you can start to work on them. But don't use Saturation till you have to. It is a noise monster.

For all of what follows you must leave plenty of room to the left of the histo peak. Do not crop this back at an early stage. You need room to work.

4) Image-Mode Lab colour. Channels. Channel a, Image, Adjustments, Brightness and Contrast. Increase contrast by 30. Ditto for b channel. (You could also try a Gaussian Blur on both these channels since it will not blur the final image but will reduce colour noise. Experiment to find out how much blur works for you).

5) Two copy layers. Set the blend mode in the top layer to Soft Light. Don't panic, trust me, and flatten the top onto the second layer. Set the second layer to Blend Mode Colour, put on a slight Gaussian Blur (0.6 ish) and flatten. Repeat if you like.

6) On Ha targets go to Image, Adjustments, Selective Colour and move the top slider in the reds to the left to drop they cyans in red. This will amaze you.

And, so far, we haven't touched Saturation once, which is as it should be...

The last thing you do is clip back the black point. Leave that till the end.

Olly

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Colour can be tricky. Looking at this I'd say...

1) You have gradients which need tackling. In Ps you can use the Eyedropper tool in Colour Sampler mode to measure your background sky in all channels. I like 23/23/23 in R,G and B. The best gradient fix is DBE in Pixinsight but if you prefer you could buy Gradient Xterminator from Russ Croman. Not as good as DBE but good.

2) Like most of us you are having problems with green noise. In PI, SCNR Green will zap that. In Ps you could get the free Hasta La Vista green from Rogelio's Deep Sky COlors website.

3) Once the colours are right but not sufficiently intense you can start to work on them. But don't use Saturation till you have to. It is a noise monster.

For all of what follows you must leave plenty of room to the left of the histo peak. Do not crop this back at an early stage. You need room to work.

4) Image-Mode Lab colour. Channels. Channel a, Image, Adjustments, Brightness and Contrast. Increase contrast by 30. Ditto for b channel. (You could also try a Gaussian Blur on both these channels since it will not blur the final image but will reduce colour noise. Experiment to find out how much blur works for you).

5) Two copy layers. Set the blend mode in the top layer to Soft Light. Don't panic, trust me, and flatten the top onto the second layer. Set the second layer to Blend Mode Colour, put on a slight Gaussian Blur (0.6 ish) and flatten. Repeat if you like.

6) On Ha targets go to Image, Adjustments, Selective Colour and move the top slider in the reds to the left to drop they cyans in red. This will amaze you.

And, so far, we haven't touched Saturation once, which is as it should be...

The last thing you do is clip back the black point. Leave that till the end.

Thank you, I shall have fun trying this out (I am assuming your comments apply to both of us who have posted images in this thread).

Tim.

Edited by StargeezerTim
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Your levels in DSS look to be too far to the right to me. I generally aim to get them lined up about a third of the way across and then up the saturation to about 24% or so. I use a modded 1200d and got more colour out with less subs on the Heart which is similar. I then up them again in levels and curves.

Peter

Hi Peter

Yeah I realise I was probably unclear and I do pull the peaks together nearer to the left and increase saturation, so sorry for the confusion - the DSS image was really just to show the width of the curves and whether that was normal - sounds like it might be....so it sounds like I need to concentrate on the post processing! Thanks!

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Hi Marky,

Let me preface my comments by saying that I'm very new to astro imaging and certainly no PS expert, mostly doddling along on a need to learn basis.

I downloaded your <500kb image to have a play with and found I could really bump the colours using CS6's Image/Adjustments/Selective Colour tool which I find I can get better individual colour adjustment with than Chanel Mixer or Colour Balance. But then I don't really know what I'm doing.  :confused:

I wont post the result of my fiddle as at this stage I don't really know what a good astro shot should look like, and PP is also very subjective.

Hi Kev, I am working around PS slowly, so will have a look at that tool and see what I can do! Cheers!

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That's about the same as my first (and only, so far) attempt at Soul with my modded camera (attached). As has been said, selective colour does brighten it up but beware of noise. Did you use a filter? I still find a UHC filter is needed on most nebulas. Also, the moon was in play last night, depending on the time you imaged. Tonight, it will ruin images up to about 2.00am. If I can't sleep I might do some as the the cloud forecast is good.  :smiley:

Think the moon affected this one as well, if I remember rightly...

attachicon.gifSoul.jpg

Thanks Tim - no filters yet, saving up a bit more cash as I was planning on a CLS Clip Filter as well. And Yeah, the moon was out in force....so few clear nights recently I just have to take what I can get! ;-) Got a clear night tonight, but might get set up and wait until later - maybe try a different target like M45, not had a pop at that one yet.

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Colour can be tricky. Looking at this I'd say...

1) You have gradients which need tackling. In Ps you can use the Eyedropper tool in Colour Sampler mode to measure your background sky in all channels. I like 23/23/23 in R,G and B. The best gradient fix is DBE in Pixinsight but if you prefer you could buy Gradient Xterminator from Russ Croman. Not as good as DBE but good.

2) Like most of us you are having problems with green noise. In PI, SCNR Green will zap that. In Ps you could get the free Hasta La Vista green from Rogelio's Deep Sky COlors website.

3) Once the colours are right but not sufficiently intense you can start to work on them. But don't use Saturation till you have to. It is a noise monster.

For all of what follows you must leave plenty of room to the left of the histo peak. Do not crop this back at an early stage. You need room to work.

4) Image-Mode Lab colour. Channels. Channel a, Image, Adjustments, Brightness and Contrast. Increase contrast by 30. Ditto for b channel. (You could also try a Gaussian Blur on both these channels since it will not blur the final image but will reduce colour noise. Experiment to find out how much blur works for you).

5) Two copy layers. Set the blend mode in the top layer to Soft Light. Don't panic, trust me, and flatten the top onto the second layer. Set the second layer to Blend Mode Colour, put on a slight Gaussian Blur (0.6 ish) and flatten. Repeat if you like.

6) On Ha targets go to Image, Adjustments, Selective Colour and move the top slider in the reds to the left to drop they cyans in red. This will amaze you.

And, so far, we haven't touched Saturation once, which is as it should be...

The last thing you do is clip back the black point. Leave that till the end.

Olly

Hi Olly...thanks as ever....

I have Gradient Xterminator on trial, although I am not sure I have managed to get it to work very well so far so still experimenting, but will also try Hasta La Vista. Pixinsight is going to have to wait a bit I think!

Thanks for the other suggestions too, I'll have a go later. Not done any of those before, but will have a play and see how I get on. As I say, still learning PS. Have the day off tomorrow, so will try and have a look at some of the tutorials I have lined up.

Cheers

Mark

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Hi Olly...thanks as ever....

I have Gradient Xterminator on trial, although I am not sure I have managed to get it to work very well so far so still experimenting, but will also try Hasta La Vista. Pixinsight is going to have to wait a bit I think!

Thanks for the other suggestions too, I'll have a go later. Not done any of those before, but will have a play and see how I get on. As I say, still learning PS. Have the day off tomorrow, so will try and have a look at some of the tutorials I have lined up.

Cheers

Mark

The thing about Grad X (from memory since I now use DBE) is to try to get it to work just on the background sky. You could select this using the colour select tool in Ps.

Olly

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Here is my one after following Ollies suggestions (DBE and Lab color) plus denoising and a little sharpening and colour balancing etc.. I think there is almost a nice image there but I should really image it again on a dark, moon free night!

Good fun this innit? Look forward to seeing Markys version. 

post-35654-0-73639800-1443115110_thumb.j

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The thing about Grad X (from memory since I now use DBE) is to try to get it to work just on the background sky. You could select this using the colour select tool in Ps.

Olly

 Yeah, the tutorial I found suggests using a select tool and then inverted the area, but I am not convinced this will work with these images as well, so something else to explore...I'm thinking I may need to start exploring Star Masks....

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Here is my one after following Ollies suggestions (DBE and Lab color) plus denoising and a little sharpening and colour balancing etc.. I think there is almost a nice image there but I should really image it again on a dark, moon free night!

Good fun this innit? Look forward to seeing Markys version. 

attachicon.gifSoulDBEollie.jpg

Will hopefully have a play later, like your new image Tim!

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Mmmmmm....well I had a play last night and largely just worked out how little I know about processing....  :grin:

Onwards!

That makes two of us... Ha.   

The lab colour and blending modes does boost the colours, and the the gamma slider can add some real punch...  but the main thing is getting good images in the first place! 

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Mmmmmm....well I had a play last night and largely just worked out how little I know about processing....  :grin:

Onwards!

IMO it is hard especially for us dslr light polluted users.

I have barely scratched the surface of processing but am in for the long haul.

Pixinsight and Photoshop have opened up a lot just by having them, all I need to do is master them. :grin:

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