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08-12-2016, 07:20 PM   #1
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Landscape Astrophotography Processing Plan

I have a mixed bag of subs from last night, consisting of::

* 4 dark frames
* 4 foregroung images
* 60 sky images
* 1 KILLER SHOT !

Each sub is 120 seconds/f3.2/800 ASA on a Pentax K-1 with a Samyang 14mm lens.
Some of these contain meteor streaks and some do not.

Normally I would pic the best foreground image and use it. Stack the sky images in DSS,
and then composite them in Photoshop for a nice finished product. I am not sure what
happens when you start stacking images with meteor streaks, but it would be fun finding out.

*** The problem is that one of thse subs contains a big fat meteor trail in a remarkable place.

Is there some way to combine this mixed bag of images gto give me a polished result that
contains my miracle meteor strike.

Any ideas appreciated!




Rick

08-12-2016, 07:42 PM   #2
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Stack with lighten blend more
08-12-2016, 10:17 PM   #3
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Most stacking algorithms are structured to remove trails in images, necessary to remove satellites, passing planes, etc. If you really want to preserve a fireball, the easiest would be to just go with the best possible pp treatment of the single frame. Otherwise, you can do the stack, then add the fireball on a top layer.
08-14-2016, 09:50 AM   #4
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DSS

DSS is supposed to have blending modes {blend lighten more?] that preserves this sort of thing.

However, I don't think that DSS 3.4 will read K-1 PEF or DNG files?

So, I need to convert to TIFF.

That brings up the question of whether to process the RAW files firest, apply the same processing to all, and the convert to TIFF for stacking

- or -

stack first, then process the final TIFF/

which is better?

---------- Post added 08-14-16 at 09:52 AM ----------

QuoteOriginally posted by K-amps Quote
Stack with lighten blend more
owever, I don't think that DSS 3.4 will read K-1 PEF or DNG files?

So, I need to convert to TIFF.

That brings up the question of whether to process the RAW files firest, apply the same processing to all, and the convert to TIFF for stacking

- or -

stack first, then process the final TIFF/

which is better?

Read more at: https://www.pentaxforums.com/forums/190-pentax-k-1/327712-landscape-astrophot...#ixzz4HKIMU32U

08-14-2016, 09:53 AM   #5
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DSS has had no problem reading DNG files here.
08-14-2016, 10:15 PM   #6
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DSS Seems to Be Having a Problem

Trying to process 3 dark frames and 3 light frames, when it is about to write the final TIFF file, I get a dialog box with a YELLOW TRIANGLE enclosing an exclamation mark !

that is it.

no text, no explanation no nothing.

I do get an autosave.tif file, and it is processed, but
I really dont understand what is going on.

wow, what crappy programming ... I would have been fired ...
08-14-2016, 11:25 PM   #7
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I typically convert raw's with some processing before blending in tiff or jpeg. I like Jbinpg's idea of adding fireball on top of the composite to give it a comet with tail, effect.
08-14-2016, 11:51 PM   #8
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Given you were shooting at 14mm I'd give processing the single frame a go, DSS isn't going to add much to your images at such a wide angle, and the noise of the K-1 at ISO 800 is very managable. What's more, these modern Sony sensors produce very little non-random noise (for your dark frames to take care of) so there isn't much of a need for a full stacking regime.

08-15-2016, 11:32 PM   #9
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Non-linear Me.

I was told that processing prior to stacking was not a great idea, mainly because many of the "image processing" functions in Lightroom, Photoshop, etc. are non-linear transformations, and they will screw up registering and stacking operations.

I have tried processing before or after stacking, and but my results are inconclusive.
08-15-2016, 11:43 PM   #10
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I may indeed be stuck with a sihgle sub, because my foregrounds are not great.

In any event, since I am not going after deep sky objects, etc. I prefer the richness and relatively low noise of multiple stacked images. If I stack 16 two-minute exposures, I have something like 32 minutes of light gathering vs. 2 minutes for a single sub.

So, take a look at this dark frame (2min @ ISO800). Notice the slight glow along the bottom of the frame. Also, seems like a lot of hot pixels ...
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08-16-2016, 12:50 AM   #11
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That picture is way too small to see hot pixels.
08-16-2016, 03:57 PM   #12
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Did you cover the viewfinder before doing your dark frame? If you don't you will get a light leak on the bottom of your frame.
08-18-2016, 10:34 AM   #13
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QuoteOriginally posted by jbinpg Quote
Did you cover the viewfinder before doing your dark frame? If you don't you will get a light leak on the bottom of your frame.
CRAP !! but, my dark frames should remove the leak effect?
08-18-2016, 01:10 PM   #14
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Nope. Astro demands good technique. One of those is to make sure you have the viewfinder covered for all exposures.
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