I'm using LR 5.7.1 on a Mac.
When I've retouched raw pictures with PS CC (and do not need the PSD file any longer) I export the PSD (that is in my catalog) as JPG and let it add to my catalog automatically. After that I delete the PSD file. That works fine.
But .... the new JPG file is not assigned to any collection. That's no problem unless I forget to do it manually after that export (and import).
That brings me to my question.
How can I find photos that are not assigned to any collection?
I tried it with a smart collection after I found nothing suitable in library filter. The search criteria I tried are Source -> Collection with any of the conditions. One with an empty value field, then with just a space and so on.
Has anybody a good hint for me?
It's so simple. I did not notice the Match operator.