Exposure and light

My scanner is stop motion, so take the information as theoretical.

Suggestion on how to unpack the question.
As you may have seen in the forum, the lens best sharpness and resolution for the typical lenses used for 8mm is between f4 and f5.6. That’s set.

Film speed motion will give you the camera exposure time, since you need to freeze the movement. A global shutter sensor (search the forum for more info of global vs rolling shutters) will be required.

The lens aperture (set) + exposure for freezing + sensor sensitivity = light required.

Good quality white LED. You will need a lot of light in a short time. You may need to flash it to avoid overwhelming the sensor. This posting provides some info. His scanner is a great example of continuous motion.