Assuming the master is 2K which I think is the majority for the basic aspect ratios we have
1.37:1 = 1332 x 1828 scaled to 1080 x 1482 for obvious reasons
1.85:1 = 1080 x 1998 (rescaled to 1038 x 1920?)
2.39:1 = 858 x 2048 (rescaled to 804 x 1920?)
For 1.85:1 and 2.39:1 is the extra info simply being cropped off or is it being rescaled? I know we would be losing a bit of picture info on the sides, but I would think using pixel for pixel info would create less problems and better picture than rescaling.