Author here. I agree with you, "full spectrum" is a generous marketing phrase for what might more accurately be called _extended_ spectrum. People way smarter

Author here. I agree with you, "full spectrum" is a generous marketing phrase for what might more accurately be called _extended_ spectrum. People way smarter than me have been able to achieve DIY spatial imaging with x-rays via compressed sensing [1] and with microwaves via phased arrays [2]. Optical wavelengths seem to be at a sweet spot of good angular resolution, varied natural sources, and harmless to humans. [1] https://www.youtube.com/watch?v=EuVgGrun1V0 https://www.youtube.com/watch?v=EuVgGrun1V0 [2] https://www.youtube.com/watch?v=sXwDrcd1t-E https://www.youtube.com/watch?v=sXwDrcd1t-E