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Old 18-01-2009, 09:11 AM
TrevorW
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DSS stacking question

Once DSS has finished stacking is the idea to align the colour channels so they intersect in the first 1/3 of the histogram before saving the tiff file or do most people adjust these outside DSS

Cheers

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Old 18-01-2009, 03:58 PM
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I can't help Trevor, but keen to see what people say. My star colours usually look like they've been through a hot wash with bleach after DSS'ing.
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Old 18-01-2009, 04:52 PM
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Quote:
Originally Posted by TrevorW View Post
Once DSS has finished stacking is the idea to align the colour channels so they intersect in the first 1/3 of the histogram before saving the tiff file or do most people adjust these outside DSS

Cheers

When I use DSS i use it just to stack. So, before saving the image I check the box which says do not embed changes. That is i dont align the colour chanels or save the default RGB/K levels, luminance or saturation.

I make all processing adjustments in PS. I find if i dont do this I lose a significant amount of colour from the image.

Cheers
Paul
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Old 18-01-2009, 05:33 PM
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I use DSS the same way as Paul.
Also, I use "per channel background calibration" as the other setting ("RGB background calibration") gives me false colours (because of LP, it makes background and faint objects gray, which is clearly not the case. I guess this setting would be adequate for pictures taken from dark sites).
The post-processing (curves tweaking and getting rid of LP) I do in DPP (digital photo professional) that came with my Canon camera.
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Old 18-01-2009, 07:46 PM
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I use DSS the same way as Paul.
Also, I use "per channel background calibration" as the other setting ("RGB background calibration") gives me false colours (because of LP, it makes background and faint objects gray, which is clearly not the case. I guess this setting would be adequate for pictures taken from dark sites).
The post-processing (curves tweaking and getting rid of LP) I do in DPP (digital photo professional) that came with my Canon camera.
Thanks Bojan,

I was wondering why it always came out grey for me

Cheers
Paul
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Old 20-01-2009, 09:52 AM
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you are most welcome :-)
Actually, this problem with DSS started to appear at some point in time here and I asked others ... so I am just spreading the answer further :-)
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Old 20-01-2009, 11:08 AM
TrevorW
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Actually I don't have an issue with DSS I was asking because I've been following the process I picked up from reading articles on the net.

I choose recommened settings in DSS then go through and select what I want based on the data and then stack.

I tried the options mentioned above and images came out worse than using the default options recommened in DSS and then I align the RGB in DSS, adjust saturation before saving.

Are you using unmodified DSLR cameras if not then what you suggest may only apply when using CCD or modded camera's.

Cheers
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Old 20-01-2009, 12:36 PM
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My camera is not modded.
However, the settings would apply to modded ones as well. What you really want is a stack with as little as possible artifacts (this is at least my philosophy.. otherwise the original data is destroyed). Unless you want to keep original raw files. But this option tends to be very HD-consuming, so I am keeping the stack and one or two CR2 files, for record).
So any tweaking on resulting tiff image is not desirable.
Also, DSS is VERY slow to read, display and modify.. any other package is 10x faster at this task (including DPP I am using).
Actually this is the main reason I use DSS for stacking only.
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Old 20-01-2009, 01:36 PM
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I actually keep the raw files that way I can try a variety of different stacking options.

What i'm trying to ascertain is what would be the best stacking option(s) to use in DSS with an unmodded camera to maximise data retention while optimising SNR and colour

Cheers
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Old 20-01-2009, 02:06 PM
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In my experience, default settings are the way to go (plus "per channel background calibration", I do not remember if this is default or not)
SNR is taken care of by a number of frames (more, the better SNR).
Colour can be tweaked in post-processing of tiff file (at least this is what I do.. I can even remove the LP while retaining the natural (or so it looks to me) colours, by setting the black treshold (as I do not have LP filter yet, of course everything below the LP noise is lost).
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