login/register

Pinball Rehab

pinball repair and restoration

Anti-Ghosting LED Comparison Anti-Ghosting LED Comparison Hot video

Before we get to our LED comparison let's talk a little bit about the problem.  Ghosting is used to describe the behavior of an LED glowing dimly when it should be off.  This will occur on a controlled lamp when another lamp or LED in the same matrix row or column is turned on.

The cause is a combination of timing in the lamp matrix driver software and an issue with the WPC ASIC.  The ghosting problem appears to be limited to Williams/Bally WPC era games, including some Data East games since they use essentially the same hardware. 

In 1995 the Williams software designers modified the lamp matrix device driver to work around the WPC ASIC issue.  In most cases this appears to have solved the problem in later games.

Although commonly used interchangeably, flickering is different than ghosting.  Flickering, or pulsing of the LED, occurs because controlled lamp circuits are pulsed and the LED's turn on and off faster than incandescent bulbs.  Flicker is also noticeable in GI circuits since they are 60Hz AC.  Most people will never notice the flicker, although some people are especially sensitive to this effect.

In other words, ghosting is when the LED glows dimly but it should be off, and flickering is when a very fast pulsing is noticeable when the LED is on.

There are three variables that will affect whether you get ghosting and how noticeable it is.  Some positions will have no ghosting at all while others will have a lot of it.  This depends on the lamp circuit and the sequence of the lighting effects.   If an LED is ghosting it will be more pronounced in exposed positions (like the Hook pinball in the video) and in inserts that are towards the bottom of the playfield. 

The ghosting issue can be solved with anti-ghosting LED's or by updating the WPC Game Rom.  See this article for an in-depth analysis of the problem and a link (near the bottom of the page) to a patched driver.  Since most pinball owners are probably not eager to patch their ROM's we have evaluated the five currently available LED solutions.

The four non-ghosting led's I tested where the 2-LED non-ghosting led ($.99) from cometpinball.com, the NoFlix Plus ($1.75EUR) from pinballcenter.eu, the 2-LED Cointaker Premium ($1.19) available at cointaker.com and the 1-LED Ablaze Ghostbuster ($.89) available from pinballlife.com.  The prices are provided as a comparison only and where valid as of March 25, 2015.

Note: Several people who are sensitive to flickering have informed me that the NoFlix Plus does a very good job of eliminating flickering.  This issue is not addressed by the other non-ghosting led's, although Comet Pinball does have an Ultimate Optix line that is non-ghosting and no-flicker.  I have also been told this product does a good job of reducing flickering.

All products solved the ghosting problem equally well (see the attached video).  The only differences where in brightness.  The Cointaker Premium and the Comet non-ghosting led where clearly the brightest and the Ablaze Ghostbuster was the dimmest, although completely acceptable.  Personally I would eliminate the NoFlix Plus due to its higher cost and the cost of shipping to the US.