SourMesen
commented
4 years ago This is possible via Options -> Video -> Aspect Ratio -> "Auto (NTSC or PAL based on game)" This will switch between a 8:7 PAR (pixel aspect ratio, e.g the pixel is not square) for NTSC or 11:8 PAR for PAL. As far as I know, this is generally the accepted pixel aspect ratios for NTSC and PAL on the SNES.
e.g, using the "240p suite" test rom, you can verify that a circle has its proper shape using 8:7 PAR:
There is no option to get a proper automatic PAL/NTSC aspect ratio seen on a real SNES. As you know, the SNES has horizontally stretched pixels and , If I am not mistaken, on real hardware the 256x224 is stretched to a 320:224 picture. On PAL systems that would be 384:224 or 16:10 if 256x240 is used due to letterboxing. This option would be very convenient as it would make the picture look more like on real hardware.