I have connected the Nintendo Switch to a 16:10 monitor (EIZO FlexScan SX2262W). The monitor's native resolution is 1920 by 1200, but I have tested that it also accepts 1080p input.
In the resolution settings, the Switch offers only “automatic” and “480p”. 480p does not work at all (which is ok) and with the automatic setting the Switch chooses 1920x1200 and stretches the image to that resolution, not preserving aspect ratio.
Is this a problem that the Switch has with all 1920x1200 monitors, or is it just mine? Is there any workaround?
(My Switch works just fine with Full HD monitors, and the Wii U worked fine with my monitor, as do other devices.)
Update: Since the question has been bumped and I am still interested in this, I will report that a recent update (4.0.0, I think) has changed the situation, but not resolved the problem. The Switch still only shows 480p as available and now, instead of outputting stretched 1920x1200, it actually outputs 480p, which leaves me with a tiny image (with correct aspect ratio) in the center of my monitor. It is kind of hilarious.
Second Update: It remains funny. Now (5.0) I get 1680x1050 (I think, I would have to check again. Slightly fewer than 1050 lines and wrong aspect ratio, that I remember). With a cheap HDMI->HDMI+TOSLINK splitter in between I get 720p, which is obviously suboptimal, but good enough for me to play Splatoon.