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General / Re: Blending Ha with Red...a new approach
« Last post by mmirot on Today at 22:20 »

The 501 nm area would have an natural aqua/ cyan color.

Most RGB filters sets intentionally cross the OIII between G and B. When balanced this give aqua/cyan.

You method would have to be changed to apply it 50/50.
General / Re: Adding Data to Existing
« Last post by pfile on Today at 22:06 »
if your optical train has not changed, you can start from #4 with the same masters on the new lights, then register the new lights, and then run a new integration that includes both the old and new lights. the old calibrated and registered lights are still good to use, as long as you use the same registration reference for the new lights.

if the optical train has changed, then you should get new flat subs, calibrate/integrate them, and then use the new master flat instead of the old one in step #4.

Bug Reports / Memory Violation Error
« Last post by Astrostar on Today at 20:24 »
Having left PI running but idle all night, I returned to processing one of the two open images. On viewing the image history I double-clicked the second entry row expecting to see the delta change from its original condition, instead the application threw the memory violation error captured in the attached file, which reads:
"At address 00007FFDCF1C9E08 with exception code C0000005 : Access violation: invalid memory read operation at address 0000000000000018"

Having recorded this information the advised exit/restart appears to behave correctly, albeit I've not as yet tried the same operation again.

General / Re: Blending Ha with Red...a new approach
« Last post by aworonow on Today at 17:27 »
If you have broad-band filters that do not overlap, then the OIII goes into the color of the filter that covers the wavelength of the OIII emission line (500.7 nm as the primary line). It is being registered by the broad-band filter that covers this the equations assume. If more both the blue and green broad-band filters cover the primary line (and, perhaps the secondary line as well), then the unmixing of intensity sources is not so simple and not really appropriate for the equations I presented. Unfortunately, 500.7 nm lies smack-dab between green and blue for Astrodon true balance filters. I suspect that people add the OIII to the green because the secondary emission of OIII is slightly greener than the primary...but still in the gap. So what you do is dictated by the filters you have and the color effect you want, especially if you decide to try to unmix intensity sources using my equations.

General / Re: Blending Ha with Red...a new approach
« Last post by mmirot on Today at 16:58 »
In so far as OIII's main emission is in the blue, it could have the same math applied to it and the B image as done with the Ha and R. Not ideal, but often usable. I just (this morning) did that with a planetary neb with some good results.

(OIII is kind of blue-green, as I read it. But I don't know how to partition the emission. Maybe proportionally to the distance to pure blue versus pure green? Some cipher'n would be required, as Jethro Bodine would say." So I just drop it into the blue for now.)


If your blending into RGB it is usually an aqua color.

So most people would distribute OIII 50% into the Green then 50% in blue.
General / Re: HDRComposition not work
« Last post by gianpri on Today at 16:58 »
Thanks Alejandro, it works but I had to decrease the binarize threshold up to 0.1400 !!!
General / Re: Blending Ha with Red...a new approach
« Last post by mmirot on Today at 16:49 »
Yes, I am an active member. I should take a trip out your way some day too.

General / Adding Data to Existing
« Last post by Farzad_k on Today at 15:44 »

I am just curious as to how the workflow will be when data is being added to the data that has already been processed. I intend to go out and collect more data on an object that I already processed.

I know that if I keep the same exposure length and the same ISO, and if the weather is about the same, then I won't have to worry about dark frames and biases.

In PI, the Pre-Processing workflow as I understand it is:

[1] integrate darks
[2] integrate biases
[3] integrate flats (if any)
[4] calibrate lights using integrated darks, biases and flats
[5] register (align) calibrated lights
[6] integrate (stack) registered calibrated lights

Where would the new data (light frames) be incorporated? Or do I have to do step [4] again.

Gallery / Re: NA Nebula and Pelican Nebula
« Last post by ppina on Today at 13:50 »
Excellente .
General / Re: Blending Ha with Red...a new approach
« Last post by aworonow on Today at 13:30 »
Upon thought (and a few "goes intos"), if any narrowband line lies entirely within a single broadband filter, the equation for mixing narrowband and broadband are the same as in the derived equation.

Max...are you a member of HAC? I am. But living in Silver City, it's a long trip to meetings and I seldom make it.

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