IC1391a - Elephant Trunk, where's the colour?

[iapa]

OSC data

• 60s exposures
• unguided
• 150 x 1.3S flats,
• 300 x 1.3S dark flats,
• 80 x 60S dark 
• 100 x 1mS bias

PreProcessing

• WBPP
• subframes selected
• imageintegration

Hardware

• ASI294MC-Pro
• ASIAir Pro
• Esprit ED80
• Field flatener
• AVX

 

 

 

 

integration.tifintegration.fitPreprocessing

 

 

 

masterFlat_BIN-1_4144x2822_FILTER-NoFilter_CFA.xisf masterDark_BIN-1_4144x2822_EXPOSURE-60.00s.xisf masterDark_BIN-1_4144x2822_EXPOSURE-1.30s.xisf masterBias_BIN-1_4144x2822.xisf

Edited August 13, 2022 by iapa

[Budgie1]

What settings are you using in WBPP on the Calibration tab under CFA Settings to debayer the image?

I found that using Bias frames with my ASI294MC Pro caused a residual of amp-glow to be left on the stacked image, so I stopped using Bias frames with this camera. I also only take 30 Darks (in a Darks Library), 20 Flats + 20 Flat-Darks for each imaging session. Do you see much of a noticeable improvement by taking more calibration frames?

[iapa]

I'll retry without BIAS

Edited August 13, 2022 by iapa

[ONIKKINEN]

Doesn't look like the data was debayered. Take a look at a closeup of the image with what looks like the bayer matrix still in place:

Dont know how to help with that in PixInsight though.

Edited August 13, 2022 by ONIKKINEN

[iapa]

10 minutes ago, ONIKKINEN said:

Doesn't look like the data was debayered. Take a look at a closeup of the image with what looks like the bayer matrix still in place:

 

Dont know how to help with that in PixInsight though.

Thanks

I did enable CFA in the script, will check parameters.

[Budgie1]

1 hour ago, iapa said:

I'll retry without BIAS

The Bias won't have anything to do with the debayering but worth a try to see what difference it makes.

Looking at you WBPP screenshot; The CFA settings seem fine but you can check whether they will be applied to the Lights by scrolling right with the Lights highlighted.

I don't know if the screenshot is of the actual run you made or just to show the CFA settings but, I also notice your master Flat and Master Flat-Dark exposure times don't match and there doesn't seem to be a Master-Dark at 60s for the Lights, although you would get warnings about these before the run started.

[iapa]

3 minutes ago, Budgie1 said:

The Bias won't have anything to do with the debayering but worth a try to see what difference it makes.

Looking at you WBPP screenshot; The CFA settings seem fine but you can check whether they will be applied to the Lights by scrolling right with the Lights highlighted.

I don't know if the screenshot is of the actual run you made or just to show the CFA settings but, I also notice your master Flat and Master Flat-Dark exposure times don't match and there doesn't seem to be a Master-Dark at 60s for the Lights, although you would get warnings about these before the run started.

The Master Flats where taken with ASIAir Pro set yo AUTO for flats.

I pulled the Dark-Flats exposure from he file name o the Flats.

When I check the flat exposure from FITS header it was 1.27999971Sec, Dark Flats are 1.29999899; approx 20mSec difference. Hope that's not going to make a difference

Re MAster-Dark, I'd just removed DARKs in case there was an issue with them.

[scotty38]

ok, just to summarise what's been said you need:

1. your Lights (obviously 🙂 )

2. Master Darks to match your lights

3. Master Flats to match your lights

The Master Darks "should" contain the Bias signal so you won't need any Bias frames. Do that and then post up the WBPP screen and the diagnostics output and all should be well at that point.

[iapa]

[scotty38]

Why have you chosen to optimise the master dark?

[iapa]

4 minutes ago, scotty38 said:

Why have you chosen to optimise the master dark?

It just gets a better calculation for the dark current. Will then run without for comparisons 

Edited August 14, 2022 by iapa

[scotty38]

But you have no Bias.....

 

Edit no Bias file, I mean you have Bias information in the Dark of course but my understanding is that to use Dark optimisation needs discrete Bias files and then you'd need to specify that the darks do not contain Bias information. Well that's my understanding anyway.....

Edited August 14, 2022 by scotty38

[iapa]

20 minutes ago, scotty38 said:

But you have no Bias.....

 

Edit no Bias file, I mean you have Bias information in the Dark of course but my understanding is that to use Dark optimisation needs discrete Bias files and then you'd need to specify that the darks do not contain Bias information. Well that's my understanding anyway.....

true

been a long night

[iapa]

I had a look at my dark flats and flats - from desperation, the histogram means are very close to the light means.

im going to try to get another set at shorter exposure and see.

also checked darks and they are the same.

camera gain was 120 in all cases - why? May be from a different camera ( there was a 18c-Pro connected before, and I may have forgotten to check that)

[powerlord]

In funny ones like this I usually try an integration with no reference data at all - just lights.

If that works, eyeball the reference data. If nothing obvious, add just flats and bias. If that works, then add darks.

It's worked for me before in identifying the ref data that had issues.