I cannot use = in the image field
This has been asked previously:
How does one search for [and find] empty container fields?
I would recommend Bruce Robertson's aproach.
I often create more fields for that from the Container field
I use Get(ContainerAttribute) function
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Because of this I can then always search in any of information inside my Container field and also just search for = in my FileName to see if I have any information in my Container field at all.
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