Deep Sky Stacker removing too much color from my Orion stack

Hi,

I do not use DSS a lot, but there are alternatives: Of course PixInsight http://pixinsight.com/,a great program.
Then there is Theli, a wonderful and free stacking software, used by professionals but it depends on Linux.
Or, you could try Fitswork, which is free as well and then there is Regim, which comes with an excellent colour calibration.
I use PI in most cases and a prefer them all over DSS

Nikita Misiura:
I used DSS with my DSLR and didn't have this issue. What do you use to stretch your final image? I do not recommend stretching it in DSS, it's terrible at this, better to use something like PS to do it.

I've been using either Photoshop CS6 or Star Tools to stretch the data, I never touch it in DSS except to glimpse what it could look like, but I always reset the changes before saving, and never apply them

And what is you camera? Do you use RAW as an nput?

I am using an unmodded Canon T3i in DSS. I always align the color channels (Align B and G with R) and increase the saturation to 20%

id recommend using adobe camera raw to convert the files to tiffs before you stack in dss. in that conversion you can also apply a lens profile correction which will remove most light falloff and help you with the processing in the end.
then save all the files as tiffs and stack in dss. once it is sacked do not use the autosave tiff.what you want to do is hit save image on the left side menu of dss then check the "save image with adjustments embedded" box. that way dss saves you a median stacked (or whatever stacking method you used) image that looks just like the inputs just with less noise.
this article by user Roger Clark will explain it http://clarkvision.com/articles/astrophotography.image.processing/

Judson Graham:
this article by user Roger Clark will explain it http://clarkvision.com/articles/astrophotography.image.processing/

I would have a read of the link below before you put any faith in that website.

http://forum.startools.org/viewtopic.php?f=4&t=912

I'm not to the point of using separate RGB channels yet, I'm only using color, though I separate it into an artificial luminence version for sharpening.I did find a solution though, DSS makes an auto save file for every stack,which for some reason contains far more color than any manually saved file. So I just restocked it and grabbed the auto save and renamed it

When you manually save the file do you check the box labeled something like "embed but do not apply settings"?  It's mandatory.  DSS settings are useful for seeing what you've got, terrible for processing.  When you open the stack in your processing program, it should look dismayingly dark.  That's correct.

Stretching always reduces color.  You have to put it back in processing.  Just part of the procedure.

It's unlikely that DSS is doing this, I used it for two years on a variety of targets with a variety of equipment and a variety of exposures,
never had the problem.

When you stretch data you inevitably lose color, which you have to restore.  A 20% increase in saturation is nothing, I used between
500 and 1000% in StarTools.

@Scott.  Do you ensure DSS is not stretching the image, as Brent does?  That's absolutely required, DSS does a terrible job of stretching.
The way I do it is to stack.  DSS shows you a stretched image so you can see what you've got.  There are sliders to change the stretch,
ignore them.  I click save image to file on the left.  In the save box I'd be sure "settings not applied but embedded" was checked.

When you open that file in your processing program it will look ridiculously dark.  Like "where's my image?".  That means you
did it correctly.  You now stretch it in your processing program.

Pretty much every experienced imager does it that way.  Because:

DSS does a lousy stretch.

As you develop in processing, you will want to perform certain operations on the linear (unstretched) stack.  A prime example is
gradient reduction, which really only works on linear data.  It reduces light pollution by looking for  a characteristic pattern.
Stretching destroys the pattern.

For a long time used DSS, I get the impression that you could be applying some unwanted adjustment to the final image, I can not access the link if I saw could tell you with more certainty which may be the source of the problem, try to change the stacking settings , such as the background calibration for each channel can help you get the desired result, but as in all the best is always the activates and error. As advice I will tell you that you should never save the image already stacked that post processes in DSS, I always got better results post-processing the AutoSave raw in another program, I use Pixinsight, but to see it with more color and not so pale you should upload the saturation in DSS up to 10-20.

Best regards.

Alberto.

Try APP (Astro Pixel Processor)  very competent all in one
Not so different from dss to start with.  Gives hi-qual integrations

Jirair Afarian:
I've noticed some reference to "saving the file" manually. Is this the same as the autofile that DSS generates? Is there a difference or advantage between the two methods?

I use the autosave file, for me a fits file, and use Star Tools for processing.  I never had a problem with DSS stacking and registering my files and I shoot in mono.  I read a long time ago that you should only use the autosave file and that is what I have been doing for several years now.  I do not know if there is any difference in using a manually saved file but the creator of Star Tools also recommends using the autosave file.  Bottom line is to use what ever works for you.  Post processing is an art and everyone has an unique way of producing images they are happy with.

Scott

Scott:

Jirair Afarian:
I've noticed some reference to "saving the file" manually. Is this the same as the autofile that DSS generates? Is there a difference or advantage between the two methods?

I use the autosave file, for me a fits file, and use Star Tools for processing.  I never had a problem with DSS stacking and registering my files and I shoot in mono.  I read a long time ago that you should only use the autosave file and that is what I have been doing for several years now.  I do not know if there is any difference in using a manually saved file but the creator of Star Tools also recommends using the autosave file.  Bottom line is to use what ever works for you.  Post processing is an art and everyone has an unique way of producing images they are happy with.

Scott

Exactly what I've been doing I use the autosave 32bit tiff file and process it in photoshop. I convert the file to a 16 bit exposure and gamma file then proceed from there. But as you see from the above poster some people believe that DSS processes the file before autosaving. I have not seen or read any evidence that it actually does.

I do notice that after converting, most of my files show a histogram with the RGB channels slightly skewed and I have to bring them together in "Levels" before stretching the image using "Curves".  The red is usually at the far left of the histogram then further to the right the green then slightly further more the blue channel is presented in the histogram. All three channels are generally to the left of the histogram however. Am I going about it correctly?

Jirair