John, shouldn't you be on a playground making fun of some kids or something?
You don't think it's humorous to write a tutorial on, and display the thousands of $$ in tools requisite for a multi-image stack, and yet miss something so blatant?
If it were me, and someone pointed this out on an article/photo I put up, I would have laughed, and had a chuckle at the irony too ... which was my only intent: to get a chuckle.
Relax, it's okay to be humorous, if the critique calls for it, which in this case it most definitely did
That is part of what we photographers should expect, when posting images, is
feedback (praise, critique, or both) when we post our images, be the critique on composition, CA, bad background ... or an errant crisper
I myself have taken multi-image stacks ... only to notice dust or something foreign on the subject.
In fact, for this very reason, "dusting" (removing all dirt, dust, hairs, etc.) is a common pre-stack practice.
So, unless this is Michael's new signature ("find the hair"), lol, my pointing out a software artifact, and an introduced one, is a perfectly harmless and playful comment on this thread topic.
On the serious side: it's also why editors and critiques are so important: it's easy for us to "miss" our own mistakes, because we're so immersed in what we're doing, whereas it's easy for others to spot them ... because they are not.
