Author Topic: PCC calibrates SHO, but not HOO..?  (Read 815 times)

Offline drmikevt

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PCC calibrates SHO, but not HOO..?
« on: 2017 August 04 08:18:13 »
I'm trying to figure this out:  the new PCC process will calibrate an SHO image just fine, but fails on the HOO image of the same data.  I keep getting "insufficient photometric data, need 5 image, got 0".  I've tried decreasing the sensitivity but that doesn't seem to help.   It does solve the image and then goes through the steps of the process, but fails at the end.  It tell me that '3 of 3 images processed successfully with 0 images with errors'.  The results with the SHO image are so, so nice that I want to see what it does with HOO. 

Any ideas?
Thanks
Mike

Offline Greg Schwimer

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Re: PCC calibrates SHO, but not HOO..?
« Reply #1 on: 2018 January 13 09:24:24 »
I'm getting exactly the same result. Any ideas?
- Greg
Scottsdale, Arizona, USA

Offline pfile

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Re: PCC calibrates SHO, but not HOO..?
« Reply #2 on: 2018 January 13 10:41:35 »
imo, and i think i've said this before, using PCC on narrowband images is definitely off label usage. to be honest i'm surprised it works at all on SHO, but perhaps it does since S and O are roughly R and B.

maybe if you mixed some Ha into the B channel it might do something. it's probably the fact that the signal in G and B are identical that's throwing it off. remember that this is photometric calibration and is assuming broadband RGB filtered images as inputs...

rob

Offline Greg Schwimer

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Re: PCC calibrates SHO, but not HOO..?
« Reply #3 on: 2018 January 13 11:29:38 »
Yup - I'm into off-label use. ;)

PCC will run on any variation I create as long as there are 3 distinct channels involved. SHO, HSO, HOS, etc all work. Any bi-color arrangement I come up with does not seem to work. HOO, HSS, etc do not work.
- Greg
Scottsdale, Arizona, USA

Offline pfile

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Re: PCC calibrates SHO, but not HOO..?
« Reply #4 on: 2018 January 13 14:27:11 »
Yup - I'm into off-label use. ;)

PCC will run on any variation I create as long as there are 3 distinct channels involved. SHO, HSO, HOS, etc all work. Any bi-color arrangement I come up with does not seem to work. HOO, HSS, etc do not work.

well thats probably it then - photometry is based on the difference in the signal between different filters, so if 2 filters have the same signal the math fails... thats why i was saying that possibly mixing in some Ha to the B channel might make it work... dunno.

rob