Page 1 of 1

Under the hood - number of slices vs. selectiveness

Posted: 11.02.2017 14:07
by CesareBrizio
Dear all:
perhaps somebody can help me to understand a fundamental concept - I browsed the forum but I couldn't find a relevant answer.

If I were in charge of manually making one picture from a z-stack of photos, I would make very different choices depending on how many images I have in my "column".
  • if few, I'd be less selective, and I would take for the final picture a wider band of pixels around those in sharper focus
  • if many, I'd be very very picky, and I would take for the final picture just the few really sharp pixels in each picture - thus, I would need less time (as long as I would take fewer pixels from each picture) and I would discard the blurred part of each picture, thus avoiding to process iteratively many blurred halos around the band in sharper focus (the byproduct of this unnecessary over-processing may be artifacts).
I'm not sure whether or not Helicon Focus is implemented in a similar way.

Plus, I'm not sure of having grasped which parameters, if any, control selectiveness.

I imagine that hyper-selectiveness may cause other problems, e.g. bridging the gap between the single pictures if some part is out of focus in every picture, but I would be surprised that the images in a 5-pictures stack and a 120-pictures stack are treated in exactly the same way.

Any clue?

Many thanks and all the best!