How can I see which students don't have a photo?

Go to Reporting > Reports > Students (tab) > Photos.

Leave it on All Students and All Forms to view the whole school and click Choose - 

Scroll through the list and you can see which students don't have a photo -

To upload individual student photos see: Upload Individual Student Photo

Also see:

• Upload and import student photos in bulk
• Photo Manager
• Why are student school photos blurry or pixelated?