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[KWhitt]

I followed a suggestion to record in 8-bit, instead of 14-bit for my hydrogen alpha setup (Lunt 60mm, Touptek G3M178MM), and that did double my FPS, which is good.  However, I noticed during stacking that the 8-bit images took considerably longer to stack in AutoStakkert, and I can't figure out why.  Does anyone have an explanation?  It's not bad if I only have a few videos to stack, but when I get lucky enough to have hours and hours of clear skies in one day, I can't even finish stacking on the same day.

 

With a short break in the clouds today, I did a little experiment with fresh recordings and have this data that shows the difference.  Both videos were 800 frames, and I stacked the top 20%.

 

                         8-bit   14-bit

Surface stabilization     52.0      5.7

Buffering and Analysis    60.0      7.7

Reference Frame            6.6      4.2

Alignment                 23.7     10.6

Stacking                  10.6      5.1

MAP Analysis               1.6      1.5

MAP Recombination          1.2      1.1

 

In summary: for 8-bit:  ~30 seconds to record, and 2.5 minutes to stack.  For 14-bit, ~60 seconds to record, and 36 seconds to stack.  All settings in Autostakkert were the same between the two stacks:  Surface, disable stab=unchecked, improved tracking=unchecked, find anchor=checked, expand, quality estimator=automatic, reference frame=automatic, 20% frames, sharpened=unchecked, drizzle=off.  I don't use any of the advanced features, and no calibration frames (I apply flats live while capturing in SharpCap).

 

Thanks,

Kristie

 

 

 

[rigel123]

No idea, I’d have to try it myself as I have always shot in 8 bit and I know it doesn’t take as long as your numbers indicate to do one image.