This unusual clock by [Moritz v. Sivers] looks like a holographic dial surrounded by an LED ring, but that turns out to not be the case. What appears to be a ring of LEDs is in fact a second hologram. There are LEDs but they are tucked out of the way, and not directly visible. The result is a very unusual clock that really isn’t what it appears to be.

The face of the clock is a reflection hologram of a numbered spiral that serves as a dial. A single LED – the only one visibly mounted – illuminates this hologram from the front in order to produce the sort of holographic image most of us are familiar with, creating a sense of depth.

The lights around the circumference are another matter. What looks like a ring of LEDs serving as clock hands is actually a transmission hologram made of sixty separate exposures. By illuminating this hologram at just the right angle with LEDs (which are mounted behind the visible area), it is possible to selectively address each of those sixty exposures. The result is something that really looks like there are lit LEDs where there are in fact none.

[Moritz] actually made two clocks in this fashion. The larger green one shown here, and a smaller red version which makes some of the operating principles a bit more obvious on account of its simpler construction.

If it all sounds a bit wild or you would like to see it in action, check out the video (embedded below) which not only showcases the entire operation and assembly but also demonstrates the depth of planning and careful execution that goes into multi-exposure of a holographic plate.

[Moritz v. Sivers] is no stranger to making unusual clocks. In fact, this analog holographic clock is a direct successor to his holographic 7-segment display clock. And don’t miss the caustic clock, nor his lenticular clock.