Originally posted by Painter The reason I do not use average in this case is that I want all the exposures to be summed. If you use average then items like the flashes will be diminished by each subsequent exposure in essence they will be averaged away. Average is good for other things like smoothing flowing water ect.
Great write-up, thanks so much for sharing!
I have a suggestion for ways to handle the issue (quoted above) in post-processing as well.
When you have your stacked images aligned, group them as a smart object, then duplicate the smart object so you have 2 identical stacks. In the top smart object, use the averaging mode "minimum" (or "maximum", I can't remember which), which picks the lightest pixels in the stack and sums them. This will composite all of your flashes.
Then, on the 2nd smart object, use the averaging mode "mean". This will average away all the noise and average out the flashes.
Then, using layer masks, brush the flashes from the top stack back in on top of the "mean" smart object. In the end you're left with the bright bulbs blended immaculately in with an averaged stack (at lower noise than the ISO you shot each frame with).
I shot this (link below) on a K-5iis a few weeks ago to string together headlight trails at sunrise. This was 23 frames shot in burst mode over 2.5 minutes of total exposure (6.5 seconds per frame, thanks to an ND filter).
https://www.instagram.com/p/BDRcff-Kkpu/
Anyway, back on topic, if this could be done in-camera instead of relying on a memory-heavy PP workflow, I'm all ears and excited for this ability in new cameras.