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Messages - rdryfoos

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General / Re: Mottles in Red channel
« on: 2019 April 18 13:08:34 »
That is a beautiful image Rodd. Nice details and lovely color.

I really don't see the problem. If you are not happy with the noise, is it possible you just need a bit more data (although 8 hrs isn't bad)?

  If you look closely at the left hand portion of the image--the red area--you can see the mottling if you really look hard.  Mind you--this is after a literal D-Day scale invasion of everything I could throw at it.  It definitely should not be there.  More data might be the answer, though i don't think so.  I did a rosette with 18 hours--mottles were still there.  Besides, I see grand images of these targets with 3-4 hours without mottles, so there must be a root cause.  It could be sky conditions.  Or optics flaws.  I sent the DSQ 106 back for inspection due to distorted stars.  Maybe the mottles are another artifact of the same flaw. 

General / Re: Mottles in Red channel
« on: 2019 April 18 12:30:42 »
To provide a bit more information, and to put this is a ascale perspective, here is the link to teh full image

As is evident, the mottles are at a small scale--which even at full resolution is not terribly noticeable.  But when processing, I often zoom way in to assess my handiwork.  Still trying to determine the possible sources: imbalance in the chroma channels?, LP?  ill advised work flow?   Poor data acquisition skills?

The forced graphics card sound promising--recommended hardware--But please, for those of us (me) that are not computer aficionados, it would be most helpful to have this translated to " use this computer, or that computer, but not THAT computer".  Unfortunately, PI will outlast most laptops (certainly mine)-so purchasing a new computer in the near future will be a necessity.  At hat time I will most definitely want to choose one that is considered as compatible as possible.   

General / Re: Mottles in Red channel
« on: 2019 April 17 15:05:46 »
Typically color patches (mottling) comes from upsampled chrominance data that is registered with a luminance image. Another way to see the mottle is through some forms of interpolation (bicubic for example)  usually when registering images. These may not be the issue in your case.

If the issue is of the type of smearing small scale color noise to larger scales- one of the solutions is to minimize the noise in the combined color channels images before any other processing. I have found that MURE Denoise is particularly good at this very thing! It despeckles data... which leads to less color mottling later.

Although the issue in your data isn't in the sky ... it definitely isn't "High" signal-to-noise based on your image. Something that measures (in a linear sense) .2-.3 is probably the minimum for qualifying as a significant signal.

Thanks, though not sure what you mean. I registered the frames to the lowest Fehn sub which I don’t remember what it was but it was not lum obviously. I tried mire seniors as well and it did not eliminate the mottled. The mottled become evident with a saturation boost- just a small one produces, or shows, them

Multiple individuals have the same issue(s)--and this is just on this thread.  The default position of "we can't reproduce the problem, so it can't be PI's fault" is not very becoming.  Clearly a issue(s) exists.  Perhaps it would be beneficial for PI to issue recommended hardware so that folks can use the same Equipment so that you Can reproduce conditions that generate errors.  I still get read errors when using DBE at least half the time--but I have stopped asking about it because I keep getting same answer  "it can't be caused by PI"--which is not very helpful, since it happens on every computer I use. 

If we can't ask you....who?  the Geek Squad (commercial computer company in USA, maybe the world)?  They have no clue how your software works and would not be any help at all. I know, because I asked them.  They looked at my computers and told me they were working perfectly.  So, again, who should we ask?  Trash the computer and buy a new one?  I tried that (not purposely, but the same result) and it did not work.  So......round and round we go

General / Re: Mottles in Red channel
« on: 2019 April 17 11:48:33 »
Yes--I dither.  I though it might have something to do with to high a value in DBE (top line of the 3-cant recall the name--default is .5).  But I tried lowering this as far as possible without elimination of points and the mottles were still there.
Some of the tutorials showing the use of DBE have had that parameter (Tolerance) as high as 5.0 without any bad effects.

I would be surprised if DBE were causing the problem. I have never had any success removing "local" bumps or mottling with this process. I use it primarily for removing my local Light Pollution which is typically a fairly smooth gradient across the image.

Hopefully you can find a way to eliminate the mottling from occurring in your Raw images.

  Me too--but I have no idea where to start.

General / Re: Mottles in Red channel
« on: 2019 April 17 10:06:57 »
Hi Rodd - Sounds like a frustrating problem.

Just a shot in the dark: Do you dither with your guiding? I know that not dithering can cause streaks which could look like mottling.

  Yes--I dither.  I though it might have something to do with to high a value in DBE (top line of the 3-cant recall the name--default is .5).  But I tried lowering this as far as possible without elimination of points and the mottles were still there.

General / Mottles in Red channel
« on: 2019 April 17 08:21:27 »
Does anyone know what causes chromatic mottling in higher signal areas of an RGB (SHO) image?  I say high signal areas to mean non background regions.  I am not referring mottled background.  Take a look at the crop from the Rosette nebula in Hubble palette.  I do not always have this problem--but sometimes.  I tried combining these stacks 2 ways--first without linear fitting to the Ha stack (the brightest) and then after linear fitting to the Ha stack (per the Light Vortex Video that indicates this is the proper way--not the way we were taught at the PI seminar, so I have my doubts).  But--regardless, I get mottles that show up in the red channel either way.  I have inspected all the channels, and it turns out that when scrolling through the RG and B channels when looking at the image, the mottles are in all channels--but they manifest themselves in the red channel (in blue for instance they look like dark regions, and in green, less dark).  But in the simplest terms--it is mottling in the red channel and I have tried everything to remove it as well as to prevent it and nothing seems to work.


General / Re: Error message at end of batch pre-proc script.
« on: 2019 April 10 21:22:21 »
Yes--I get lots of errors--when I use DBE I get memory read errors that require me to reboot the computer.  It happened once after BPP--I just ran iot again and it worked.  If they can't duplicate the problem, they will not provide any guidance. 

Gallery / M82 HaRGB and an experiment
« on: 2019 April 04 13:40:31 »
TOA 130 with ASI 1600.  No luminance yet--just Haand RGB.  I am looking forward to collecting some lum.  I decided to take longer subs with teh bASI 1600.  previously I had been taking hundreds of 30-60sec subs, but was never really satisfied.  I think the longer subs help (its my processing that topples the turnip cart!)

Red: 46 300 sec
Green: 53 300 sec
Blue 51 300s ec

The second image is a true experiment.  All I had at teh time was Red, Green and Ha.  I though--"what can UI make from that?"  The answer is this image--much more natural looking than I had thought it would be.  I find it amazing that there is such a strong blue presence when there is no blue data in the image.  It kind of reminds me of the Hubble Palette.


Gallery / Re: M78 HaLRGB
« on: 2019 April 04 13:30:50 »

Gallery / M78 HaLRGB
« on: 2019 February 24 10:19:41 »
I felt I had no choice but to remove the old topic--the image had to go!!  Here is a much better representation of this target with the data at hand.

Gallery / Re: NGC 2403
« on: 2019 February 16 09:19:08 »
Looks great--I am switching to 1960mm FL tonight for some galaxy hunting.  I hope the Gremlins don't make me run for refractor cover!

Gallery / Re: NGC-1333
« on: 2019 February 16 09:13:50 »
Hahaha, yes you're definitely at a disadvantage with 2 fewer mounts than scopes :-)

We're awaiting one new mount and two side-by-side adapter plates which will convert our two 400mm systems to two dual telescope systems. That will bring our count on property to 9 LOL.
  Man, what I wouldn't give for your set up!

Gallery / Re: IC-1396 Close up and far removed
« on: 2019 February 16 09:12:46 »
Hello Rod, both renditions are excellent. Love the sharpness, color and saturation that you got!
Thanks Jose.  The ASI 1600 with its small pixels helps keep the resolution fairly high even with a focal ratio of 318mm

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