Differences

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--- stacker:docs:faqlist [2020/06/29 19:07]
rjlittlefield Part of my subject looks transparent. What can I do?
+++ stacker:docs:faqlist [2020/08/23 00:06]
rjlittlefield My stack got shot out of order. What can I do?
@@ Line 61: / Line 61: @@
   * [[#why_did_the_software_reverse_the_order_of_my_images|Why did the software reverse the order of my images?]]
   * [[#can_i_directly_control_the_order_that_images_are_processed|Can I directly control the order that images are processed?]]
+  * [[#my_stack_got_shot_out_of_order_what_can_i_do|My stack got shot out of order.  What can I do?]]
   * [[#why_do_my_saved_output_images_look_washed_out|Why do my saved output images look washed out?]]
   * [[#what_does_retain_extended_dynamic_range_mean|What does "Retain extended dynamic range" mean?]]
@@ Line 294: / Line 295: @@
 One exception occurs if your subject is liable to move away while you're shooting.  In that case you should start at whichever end you consider most important, so that if the subject does leave you may still have something useful to work with.
 ===== Do I need a focus rail? =====
@@ Line 474: / Line 476: @@
 By removing the checkmark on "Automatic order" and adding files one at a time, you can set exactly any order that you want.
+===== My stack got shot out of order.  What can I do? =====
+In many cases there's a simple trick that handles this problem.
+The trick is this: after you've processed the stack at least once, so that all the images have been aligned against each other, then do a File > "Re-order input files" > "Sort by Scale". If the files were originally not in strict focus order, chances are they will be in strict focus order after the sort is done. Then you can do another Stack operation to take advantage of the improved ordering. In especially difficult cases, it may help to do the steps of stacking and "Sort by Scale" a couple of times, to give the software the best opportunity to accurately calculate scale.
+To understand how the trick works, first note that with most optics, the image changes size along with focus. Depending on the lens, the image might get smaller or larger as focus moves back, but it's probably only going to do one of those, and it will do it consistently and by a large enough amount to be reliably determined by the computational alignment process. Fortunately, the alignment process can usually determine scale accurately even when the images are initially out of order, and then sorting by the recovered scale puts them back into order again.
+The nice thing about "Sort by Scale" is that it doesn't require much thinking or mouse-clicking. The alternative is to figure out by eye what the focus order was, then manually add files into the stacking software one at a time or in appropriate groups to get the correct ordering.  Alternatively, some people rename their image files so as to be in focus order when sorted by name.
 ===== Why do my saved output images look washed out? =====