[hilbert42]

Well, that's one way. Monitoring/surveillance cameras in hot spots in nuclear facilities are often known to have horrible fuzzy images (sometimes it's difficult to see what's being monitored).

It's an interesting question how close one would have to get for the CMOS sensor to register notably in this instance. Given the stated radiation signature of this sample it's likely one would have to get pretty close, so it may not be a useful technique.

I can't recall having read anything about smartphone CMOS sensors and radiation thresholds so I'd be interested in hearing from anyone whose knowledgeable about the matter.