WBPP fails on the 2nd Local Normalization process and does not create master lights

Richard Sauerbrun

Hello Adam,

This one seems very strange as my data looks very clean and the processes run flawlessly almost to the end, then fails. I was shooting with an ASI2600MC Pro, which has almost no amp glow, so I did not include darks. I have 120 subs, divided by filter name (C1 - H-Alpha and Oxygen III and C2 - Sulpher II and Oxygen III). into two groups. Everything seems to line up and the pipeline looks great.

Local Normalization on the C1 group completes fine, but the C2 group fails and WBPP quits.

I have attached some screen shots and logs to help analyze ... thanks as always for your excellent assistance.

BlockHead

I do not think this is the cause of your issue- but you are doing something you do not intend.

Look closely at the calibration screen. Do you see how you have "Auto" Darks for the calibrating the lights? And note there is a check mark in the Darks column for the lights. You *are* subtracting darks... WBPP is going to match to the best of its ability which is to choose from the only available darks (which are your darks for flat field images). This is kind of like subtracting a bias frame which is perfectly fine...and honestly makes me feel better because you are removing the bias. 

If you really wanted no dark subtraction- you need to turn off the Auto matching.

Concerning the LN issue- this WBPP run looks dirty to me. It appears you have tried to run it several times?

I would suggest a clean run from scratch. Clear the cache, reset files (remove previous output).

Be certain that the calibrated data does not have any zeros.

You are working with NB images... and it appears yo did not use a pedestal. Is this intended? Have you checked to make certain?

-the Blockhead

Richard Sauerbrun

WOW ... you are very perceptive ...

Yes, I tried to run this data again after a failure, and obviously did not get it totally cleaned up for the second attempt.

I will add this lesson to my constantly growing "now I know how to do that" lists of skills. When I choose not to use a dark (other than the dark flat), I have to turn off the "auto" setting.

But I do need to better understand your statement ... "You are working with NB images... and it appears you did not use a pedestal. Is this intended? Have you checked to make certain?"

The images were shot with the 2600MC (OSC) camera, and I used two dual narrowband filters (Askar C1 & C2). What is a pedestal? And how do I produce and incorporate one?

BlockHead

See: 

-the Blockhead

Richard Sauerbrun

Thanks again, Adam ... now I fully understand the use of a pedestal to avoid loss of data.

And if you are interested, here is my final image. You may agree that I went a little nuts pushing the various colors and saturation. But this was my first image using the Askar C1 and C2 dual narrow band filters.

And my first effort in PI working with the narrowband data.

Such FUN!