Pedestal for NB using WBPP

Bruce Donzanti

Hi Adam

I watched your video on this topic but I have 2 questions:

1- I can't seem to find the area to place in the value as you demonstrated in your video.  Has it been moved?

2- Can you explain why a pedestal value, like 100, not just be auto populated when running NB data? 

Thanks,

Bruce

BlockHead

Bruce,

1. What version of WBPP are you using? You have to click on a lights group in the calibration tab to see it in the calibration settings. Every word I wrote in the previous sentence is significant.

2. Not all NB data with all sensors requires a pedestal. When it does, the actual value needs to be determined. In the next soon to be released version of PixInsight- WBPP will subtract darks and look for negative values. If it finds enough it will determine the best pedestal numerically. However, there are complications. For example OSC data has THEE DIFFERENT ANSWERS. See? It is always complicated. I can imagine situations where, because of some other issue, a pedestal is automatically calculated by being tripped up due to a bad dark or some other issue. This is why a pedestal will not be fully "auto populated" ... our brains figure this stuff out better than a complex set of logic that might not account for all scenarios.

-the BLockhead

Bruce Donzanti

Version 2.3.2

I understand all NB data will not require a pedestal.  What I was trying to understand is, what would be the harm in having a baseline of 100, even if it was not required, and then one could increase it if needed.  However, your answer explains why that might not be a good idea.  And I like the fact that the next release will address this in a more apparent way for the user.

Thanks 

BlockHead

Part of the answer is- with an unknown value- you *could* choose some high number that likely accommodates all such issues. However- this does eat into the dynamic range of your sensor. You full range of possible values is the saturation level minus the pedestal. Small pedestals are no problem... but big ones eat into your nice detector's performance.

-the Blockhead