3D hologram fan display
Here is a picture of a simple toy clock that runs off a USB port.



The picture was taken at 1/40 sec, I didn't quite get one revolution. So about 1/30 would be one revolution.

The LEDs are on only one blade. The minimum arc that I see is about 2.8 degrees, so the LEDs are updated about 128 times per revolution (360/2.8).

Therefore, the LEDs are updated about 3840 times per second (30 * 128).

Now this is just a small toy. Something larger will need to update at a smaller angle. You will need to do some geometry calculations to get an update rate for a whatever "pixel" size you choose.

Realize that making something close to photo-realistic from scratch is a massive job.