WBPP question about Mosaics

Gary Barr

I am working on a 4 panel mosaic.  I have more subs of some filters for a given panel(s) vs others.  I want to see how my project is going and the key I've found is to make sure within a respective filter, all panels have the same amount of total time.  So, is there anyway for WBPP to say pick the best 37 subs all of the same filtered panels?  I can go into WBPP and just delete each filter for a given panel to make sure all times equal for set.

Ex.  I have 72 subs for Oiii panel 1, 47 subs for panel 2, 43 subs for panel 3, and 40 subs for panel 4. So, 40 is the lowest amount of time so I want all the other ones, just to see how the project is going. That means throwing away, just for this run, throw away 32 of Panel 1 Oiii subs, 7 subs for panel 2, and so on.

Anyway to have WBPP pick the 40 best and not use the others for a given filter set?

I can just remove selected to make sure all Oiii panels = 40 but maybe I'm removing some really good subs.

BlockHead

Hi Gary,

This isn't the approach I would take. When you integrate 72 subframes in one panel and 40 in another (for a given filter) there will be a slight difference in signal to noise- but is likely will not be noticeable. The average of 40 frames will be good- and 72 might be al little better- why handicap the hard won good data you took?

The above assumes the data in each set is of relatively similar quality. Of course, this will not be the case in reality. This is why the weighting schemes are important. Applying a consistent relative weighting scheme will likely be all that is needed to be certain that each set (panel) has the best integrated result.

So I say, do not worry about the fact that you do not have matching total times. There will not be a mismatch in brightness or anything like that. Just a difference of S/N- but you have met the criteria of number of frames necessary to met the statistical needs of rejection (more than 20 frames is plenty). 

So in conclusion- produce an integrated result from all reasonable frames with proper weighting. This will give you the best results. You will note that in my tutorial on the Draco Nebula (Horizons), I make no distinction between the total exposure time with my two panel mosaic.

-the Blockhead