My point was more like that even IMAX film doesn't quite get to 18k equivalent, more like 12 to 16k. Honestly, anything above 4k (for normal widescreen content) even on big screens is barely noticeable if noticeable at all. THX recommends that the screen should cover 40° of your FOV; IMAX is what, 70°, so 8k for it is already good enough. Extra resolution is not useful if human eye can't tell the difference; it just gets to the meaningless bragging rights territory like 192 kHz audio and DAC-s with 140 dB+ S/N ratio. Contrast, black levels, shadow details, color accuracy are IMO more important than raw resolution at which modern 8k cameras are good enough and 16k digital cameras will be more than plenty.