How 3D Hologram Fans Work (and Why They Are Not Really Holograms)
It is a spinning strip of LEDs and persistence of vision. Knowing that explains why some content looks amazing and some looks muddy.
The trick is speed
A hologram fan is two or four blades, each carrying a strip of LEDs from the hub to the tip. The blades spin at about 600 to 700 rpm. As each blade sweeps around, the LEDs change color hundreds of times per revolution. Your eye cannot follow individual LEDs at that speed, so it blends them into a solid circular image. The effect is called persistence of vision, the same reason a spinning sparkler looks like a ring of light.
Why it looks 3D
Nothing about the image is actually three-dimensional. What sells the effect is that the fan is nearly invisible when it spins, and any black part of the video is simply LEDs turned off. A rotating product rendered on a pure black background appears to hang in the air in front of the wall, with no screen edge around it. Your brain reads “object floating” and fills in the rest.
This is also why placement matters. A dark wall behind the fan and moderate room light make the illusion strong. A bright window behind it or direct light on the blades reveals the fan and flattens the image.
What that means for content
The format has three rules:
- Black background, always. Anything not black is lit and competes with the subject.
- Bold shapes, few details. A 20 inch fan has around 550 LEDs across four blades. Thin lines and small text turn to noise. Big logos, single products and short words read well.
- Motion sells it. A still logo is fine, but a slow spin or reveal is what makes people stop. Ten to fifteen seconds is the right loop length.
Our video format guide covers the file settings. Our content library is built on these rules.
Resolution and LED count
Each LED is a pixel on the radius. A 224-LED two-blade fan gives roughly 512 by 512 effective resolution; a 552-LED four-blade fan gives about 1024 by 1024. More LEDs also means brighter output because more of the circle is lit at any instant. That is the whole difference between a $40 fan and a $150 one of the same size, and it is visible from across the room.
Noise, power and safety
The motor and blades make a low hum, similar to a desk fan on low. Power draw is 15 to 70 watts depending on size, which costs a few dollars a month to run all day. The blades are rigid plastic spinning fast, so the fan should be above reach or inside a cover in any public space.
Questions we get asked
Is a hologram fan a real hologram?
No. A true hologram records light fields. A hologram fan is a persistence-of-vision display: LEDs on spinning blades draw an image so fast your eye sees a solid picture floating in the air. The 3D effect comes from the black background disappearing against the wall.
Why does the image look like it is floating?
The LEDs only light up where the image is. Black parts of the video are simply off, so you see the wall behind the fan. The image appears to hang in space with nothing around it.
Why do photos look bad on a hologram fan?
The display has a few hundred LEDs per blade, so its resolution is low, and any non-black area is lit. Photos with backgrounds turn into a bright blur. Bright shapes on black are what the format is built for.