[dbttdft]

Hmm, I haven't thought this far into it, what matters is probably how long the persistence of vision of the human is.

For the LG CX OLED (https://tftcentral.co.uk/reviews/lg_cx_oled) (oddly one of the only OLEDs that have BFI) we can see they have no problem pulsing the pixels on on for only 3-4ms (https://tftcentral.co.uk/images/lg_cx_oled/bfi_120_high.png) (5ms divisions), resulting in these images (which I can't tell how representative of a human are because I don't know if the camera exposure matches human vision and the camera is probably wobbling at such high speeds, adding more blur than a human would see which is why these pursuit camera pictures are always blurry to hell - IIRC all those LCDs from the last 6 years with half working BFI aren't actually blurry, they are just buggily implemented so they have the top of the screen and/or bottom showing double images, each image is crisp, just doubled):

https://www.tftcentral.co.uk/images/lg_cx_oled/pursuit_120hz...

https://tftcentral.co.uk/images/lg_cx_oled/pursuit_60hz.jpg

If you just take a 240Hz OLED and blank 3/4 frames to get back a 60Hz image I'd be half surprised if that actually looks blurrier than a CRT.

EDIT: yup, just tested one of my garbage LCDs even on 75Hz with BFI enabled in the monitor menu, the image is perfectly crisp, just there are artifacts everywhere, mainly double images. That wouldn't happen with OLED with BFI (with BFI in the hardware/firmware obviously to minimize the on time beyond just dividing the frame rate).

[dbttdft]

On second thought I think duration of persistence of vision (or afterimages) doesn't matter, but more the velocity of the object which your eye is following and the amount of angular "resolution" your eye can perceive. If your focus moves X amount while the object is lit, if that distance is more than the angular "resolution" your eye can perceive, it will appear as some blur behind the object.

You made me think about an interesting point I long avoided going into.