On Jul 8, 2020, at 6:24 AM, John Gillespie <john@...
The alternative is to load all the images individually then adjust the opacity for each item, which needs to be done in proportion 1/N where N is the position from the bottom of the stack. So for 3 images it is 100% then 50% then 33%. With more than 5 images this is tedious and increasingly inaccurate as the percentage must be a whole number. So the first version is better if you are happy with a strictly equal contribution from each image. The second method is easier if you want to experiment with different weights.
This is how I make the par versions, a stack of five layers with the top four at opacities of 20, 25, 33, and 50. I use this approach for flexibility. I make the tentative par version a day ahead of time based on what I think then are the five best versions, and then if better ones come in at the deadline it’s easy to substitute the appropriate layer(s).