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stonedunicorn

DEEP SKY STACKER output image problem

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I am not sure how much you can expect from 2sec exposures.  You need longer exposures for starters.

This is what I got from the Linked tiff file.

Bit confused because some of the posted up images looked as if they had been done with a Newtonian.

Carole 

 

 

ANDROMEDA Stoned Unicorn SGL.png

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1 hour ago, Stub Mandrel said:

I used these curve settings in DSS, actually I have made it too light.

image.thumb.png.59a9b162d133b37b377bf19a51a769f3.png

Here's a go in photoshop. I think you need more, slightly longer, subs to get the colour out. tehre's hardly anything other than blue in your data.

ANDROMEDA.thumb.png.ba763a14d3d852096a6816d61b2e5877.png

Would love to see this in full quality! Looks very good you pulled more data from the actual galaxy. Thanks for trying! I am uploading all the raw files if someone wants to do some further editing. Sadly this was manually tracked thats why i used 2s exposure 320mm FF didnt allow me much more. But i got a pretty good feeling on what this would look like with a tracker! 

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I think there's is more mileage still just take more frames to combine to this lot and restack. IF they do not quite line up you'll just have a bigger edge to crop off to remove stacking artifacts.

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Hi stonedunicorn

I have the same issue as you (although I have around 2-5 min exposures).

When I bring the DSS stacked image to Photoshop it is dark and monochrome looking.

I have to stretch it a huge amount and it gets very noisy and ugly. I try to add saturation, but as it looks monochrome all I get is an overall increased hue to the whole image--no individual colors.

I have seen many people on the net say to not adjust curves/saturation in DSS which makes sense, but it never works for me. The only way I can get it to work is to adjust curves/Saturation in DSS and then bring over to Photoshop. But DSS is not great for that and introduces noise and artifacts to the image.

So I cant understand how many people make it sound so easy. If you have got an answer to this issue please post it here as I would love to know.

Also note I have recently tried trial versions of APP and Pixinsight and was able to easily  get good brightness without noise, and good color in my images.

Thanks JD

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Have a look at budgetastro.net, Doug has shared a couple workflows from DSS into Photoshop. Follow them and see what image you get.

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Thanks Bright Giant

I did catch a setting or 2 in DSS that was helpful, so thanks for that.  Most important was dont tick "set the black point to zero" in 'RAW/FITS DDP settings' or you can get a very dark image that no amount of stretching will fix.

I restacked an image over and over again with different DSS settings and bringing over to PS with or without settings embedded in the 16bit tiff, but the best image is always with basic settings done in DSS and embedded in the image. Im disagreeing with the majority on the net (hence my frustration) but its the only way I can get the better image.

Thanks again

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4 hours ago, johneta said:

 Im disagreeing with the majority on the net (hence my frustration) but its the only way I can get the better image.

 

Folks forget that an initial stretch in DSS is done on 32-bit data so getting rid of the zero-data dark/light extremes of the dataset in DSS before transferring to a 16-bit editor can make sense.

I now save as a 32-bit FITS, do the initial stretch in FITS liberator, then save as three RGB 16 bit files for PS.

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MM interesting. 'save as three RGB 16bit files for PS'  -- are you doing RGB seperate captures?? I use DSLR at the moment, could I do the same but save as a single 16bit file for PS.

 

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8 hours ago, johneta said:

are you doing RGB seperate captures??

Fits liberator splits it into three separate image 'planes'.

I experiment and apply the same stretch to each plane, but change the white and black points to suit the data.  This makes colour balancing easier.

It is a horrible program to use though.

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Hey thanks alot. That really is a missing piece of information.
I haven't seen anyone else mention that. Makes a lot of sense.
I had a play and did it a similar way that you described and yes it works well  !!

Yes it is horrible to use but you only have to do a few things on it and your done I guess.
I've got the methodology sorted now so I will practice it and it looks like it will give good results.

It really surprises me that so many others don't seem to know about this, but it seems like a crucial step.

Thanks Again :)

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Show us the proof that this works better than normal methods, how about comparison images.

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Posted (edited)

Thanks for the suggestion of pics Blue Straggler.

I have now spent an embarrassing number of hours on stacking these images and trying different options.

To cut a long story short.. My original problem of not being able to take Autosave straight to PS doesn't seem to be too much of an issue now.
I found that once I started to really stretch and add saturation to the image that some bad posturizing started appearing and I could not get rid of it so any further editing of image was pointless
But I stumbled across a weird issue in my PS. At a certain zoom level (Wider View) while I was editing the posturizing was visible BUT then when I zoomed in just one more click the posturizing dissapeared. This made me think of saving the image as a 16 bit tiff file at this stage and see what happened. When I saved the image it had NO posturizing and was clean and smooth. So the Weird artifact is added by PS just at certain zoom positions but is never visible in the saved image. A workaround would be to save the image early on in the editing phase and reopening it (16bit Tif). Then it edits as if its a normal image.
It may be a bug/quirk of PS when you convert the image from 32bit (from DSS) to 16 bit when you first bring it into PS ??

So anyway now I find that editing an Autosave and an adjusted DSS image with settings embedded, give about the same outcome when adjusting in PS.

Bringing a AutosaveFits DSS image into Fits Liberator and then bring the R,G,B images into PS and combining them into an RGB image is similar but for me slightly worse (I did struggle getting good contrast in Fits Liberator when I stretched mages though)

So all in all I can now not see much difference in the 3 different methods. Although I would pick this one --Do very basic adjustments in DSS, save as a 16bit tif with adjustments embedded and used, and then edit in PS.
It can be very hard to do comparisons sometimes due to the time it takes to stack and edit. You can get pretty lost in the middle of it all. Thanks for the suggestions.

Here's the images I was talking about.
Its of a Dark nebula close to the southern cross pointers (I'm in New Zealand). I found it a pretty hard subject as its quite dim and hard to pluck out detail in amongst the sky glow.

I use an Orion 8" F4 Newt but I haven't got a coma corrector yet so please excuse the nasty stretched stars away from center. Camera is Canon 1200d(Rebel T5) unmodded. 

Image is about 1hr 40mins of lights total (Dithered).  No darks, No Flats, No Bias

Image 1.   1 x light image unaltered (of the 24 or so).

Image 2.   Stacked in DSS, Basic adjustments made and embedded and used in saved image, then edited in PS     (1st FAVORITE)

Image 3.  Stacked in DSS, Autosave saved in Fits format, Autosave brought to FitsLiberator, FL opens it as 3 separate R,G,B greyscale images then you stretch them there and save each one as a 16bit tiff,then bring into RGB channels of a PS image and combine them to create an RGB image. Then just normal PS editing. (3RD FAVORITE AS I HAD ISSUES GETTING GOOD CONTRAST ON SEPARATE RGB IMAGES-I COULD PROBABLY DONE BETTER WITH MORE PRACTICE ON THIS ONE)

Image 4.   Stacked in DSS, Autosave saved in 32bitTif format,  Brought into PS, converted to 16bit with Gamma and exposure setting, then edited in PS as usual. (2ND FAVORITE - THIS SEEMED ESSENTIALLY THE SAME AS IMAGE 1 BUT I DIDN'T FINISH IT OFF VERY WELL AS I WAS GETTING SICK OF IT AT THAT STAGE. IF I WAS FRESH I THINK IT WOULD HAVE NETTED THE SAME RESULT AS IMAGE 2)

Image 5.  This is a screenshot of image 4 showing the posturizing I mentioned. As I said this weirdly dissapeared when I either zoomed in a bit or saved it as a jpg or tiff

L_0006_ISO1600_270s__17C.jpg

Dark Neb DSS settings then PS.jpg

Dark Neb DSS NO settings FitLib then PS.jpg

Dark Neb DSS Autosave no settings then PS.jpg

posturize.jpg

Edited by johneta

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