Drizzle Integration and alignment

[rdryfoos]

When I align my subs I align all subs at the same time to the same reference sub.  Is this a good idea with drizzle?  I fear that when the software is progressing through the operation, it will not differentiate between the last sub of the Ha channel, lets say, and the first sub of the OIII channel.  When I separate the various channels through integration,  will there be issues?

Thanks
Rodd

[stevek]

When I have chosen my reference alignment frame as the one with the smallest FHWM (always a luminance and always a frame that has itself been calibrated and cosmetically corrected) I then align ALL my subs in the data set of all filters with star alignment tool with the generate drizzle files in one operation and shove the whole lot into a "registration" folder.  It's later, in Image Integration, where you will integrate the separate filtered subs (and associated drizzle files) as different colour sets.

Since each sub is aligned with the reference sub as a separate iteration of the process - you can see this in the console - I can see no reason why you have to do each filter's subs as separate runs of the Star Alignment process for that filter.

[rdryfoos]

Well--drizzle works by incorporating the little dither movements (can't drizzle without dither).  There is no correlation between a red sub and a green sub that were shot on different nights with respect to dither movements.  I do it the way you do as well--though I don't drizzle very often--don't really see the benefit.  I was just concerned with the way it works with subs of different filters.
Rodd

[stevek]

Yes, each time it registers a sub with the reference sub it generates a drizzle frame unique to that sub.  So does not matter if different filters mixed in the same run of the process as long as they are being registered to the same reference frame.

[rdryfoos]

Yes, each time it registers a sub with the reference sub it generates a drizzle frame unique to that sub.  So does not matter if different filters mixed in the same run of the process as long as they are being registered to the same reference frame.

Thanks--that is good to know
Rodd