My CRT says it can display 480i, 480p, 720p, and 1080i. But does it effectively have a "native resolution" like LCD & Plasma TVs do requiring some sort of scaling when dealing with different image resolutions?
For example, if the CRT is fed a 480i image, does it have to scale it in any way? An LCD TV would have to scale a 480i source to 480p (at a minimum).
Note that a 1080p LCD has to be scaled to 1080p.
"TVs vs. monitors" is an ambiguous comparison. Video monitor? Broadcast monitor? Computer monitor? The silly "TV/monitor" marketing term applied to consumer-grade TVs with video inputs?
720p has a refresh rate of 45KHz, whereas 1080i is 33KHz and 480p is 30KHz.
Or in other words, 1080i requires only a 10% increase in refresh rate over 480p, but 720p requires a 50% increase.
So the answer depends on the cost of higher bandwidth versus costs of a deinterlacer+scaler. Or, in the days before ATSC tuners, simply reject 720p input.
I've seen one early CRT HDTV that would accept a 1080i video signal, but not a 720p. The electronics and tubes (it was a rear projector) didn't have the bandwidth to do 720p, and a deinterlacer+scaler wasn't inexpensive enough at the time. (It didn't have an ATSC tuner to nix that question.)
I have a flaky CRT projector that can display 1080i without a problem, but has issues with (the higher refresh rates of) 720p as the unit warms up. Seems like as the PJ heats up to normal operational temperature, the bandwidth capability of the circuitry decreases. The cause is not likely to be a power supply issue because the PSU has a cooling fan, whereas the CRT electronics rely solely on natural convection for cooling.
Sorry, I got lazy and should have wrote computer monitor. Yeah I'd like to forget about that silly TV/monitor marketing term.