Converting a Pinball Machine to LEDs Using LED OCD

I replaced the incandescent insert lamps with LEDs in my Getaway. LEDs really make the inserts pop, but using LEDs in these old pinball machines can cause ghosting and strobing. This video demonstrates those issues, discusses ways to mitigate them, and shows how the LED OCD add-on lamp controller board alleviates them entirely.

00:00 - Incandescent vs. LEDs
01:01 - Problem with LEDs: Ghosting
02:07 - Problem with LEDs: Strobing
03:06 - Solutions to problems with LEDs
04:09 - LED OCD
05:04 - LED OCD: Contents
07:09 - LED OCD: Instructions
12:35 - LED OCD: Installation
14:22 - LED OCD: Before/After comparison

http://www.ledocd.com

Ramblings about perception of strobing:
I'm pretty susceptible to the effects of LED strobing, but it seems that some people aren't. I find this really interesting. Back in the mid 2000's when LED lights started becoming more prevalent, certain car tail lights (specifically Cadillac) really bothered me. I suspect they were controlling their brightness by strobing them. They were lit steadily while braking (bright), but strobing otherwise (less bright). The strobing frequency must have been pretty low because I found them very distracting. Same deal with LED Christmas lights at the time. Those early LED strings didn't include rectifiers, so they strobed with the mains alternating current (60Hz in USA). It was very distracting to drive past a house with LED Christmas lights--even if just one string out of many was LED. LEDs can cause some interesting temporal light artifacts. Moving your vision across strobing LED lights can cause a Phantom Array effect where you see multiple copies of a strobing light as your vision moves across it (you can observe this by panning a camera quickly past LEDs). Rapid movement across multiplexed lamps can cause them to "break up", where multiple elements in a display appear to separate from each other (you can observe this by looking at an LED digital clock while chewing hard candy). Pinball machines lit with LEDs suffer from both of these problems because they multiplex, and therefore strobe, their lamps. I think how susceptible you are to strobing has to do with how your individual brain processes Saccadic Masking, which is how your brain deals with the rapid movements of your eyes (called Saccades). When you move your eyes, your brain stops processing visual input during the movement so that you don't see the blur of vision across your retina. You don't perceive this lapse because of Transsaccadic Memory wherein your brain somehow constructs a seamless visual picture even though your eyes may be darting around. Related to Transsaccadic Memory is Chronostasis, where immediately after a saccade, your brain persists the visual image for longer than normal--for example if you shift your eyes to look at a ticking clock, the second-hand may appear to freeze briefly when you first look at it. When this video shows slow-motion footage of LEDs strobing, you can see that only one or two inserts are lit at any one time, even though at normal speed all of the inserts would appear to be lit at once. Maybe chronostasis is freezing my vision so that I only see a couple inserts lit at once before my vision resumes and I see all of the inserts. How susceptible you are to strobing on pinball machines may have to do with how you move your eyes while you're playing--either by voluntarily following the ball or by involuntary microsaccades caused by visual fixation. Or maybe how susceptible you are depends on how your brain processes saccadic masking. I don't know; I'm not a vision scientist. I just know that I am particularly susceptible to the effects of strobing and that I never considered putting LEDs in my machines until I played machines that were equipped with LED OCD. LED OCD completely eliminated any strobing artifacts for me.

https://en.wikipedia.org/wiki/Saccade
https://en.wikipedia.org/wiki/Transsa...
https://en.wikipedia.org/wiki/Chronos...
https://en.wikipedia.org/wiki/Multipl...
https://en.wikipedia.org/wiki/Fixatio...