Top Three Mistakes when Buying A Used Projector for Projection Mapping

This is the easiest mistake to make when buying a used projector. Why? Because the prices are so much lower than laser projectors, it’s difficult to resist. Here is why you don’t want to buy a used projector that uses a lamp.

Governments around the world and in California have set a hard timeline to ban the use of mercury lamps. Besides being considered toxic waste when they burn out, most of the major manufacturers that make these lamps are discontinuing production of low volume models, which will make them more expensive – assuming you can find them at all when your lamp burns out. In fact, nearly a dozen major brands have exited the projector business in the last 10 years due to this issue, including market leaders like Dell, Canon, Hitachi, and Casio.  Last year Epson even produced the first ever disposable lamp mercury lamp projector. Just use it until the lamp burns out and then throw it away. Products like that make it easy to read the writing on the wall when it comes to projectors with lamps.

Projection mapping needs a lot of light. But new mercury lamps lose a ton of light shortly after they are used, which can turn a 4000-lumen projector into a 3000 lumen one in a few hundred hours.  The brighter the projector, the lamp gets more expensive, and it loses light faster. For example, a used Hitachi WU8450 projector can be found for under $500, but the replacement lamp is only rated for 2500 hours and can cost over $500. That’s a big investment after a few years of use for old technology. Purchasing replacement lamps for older projectors can be very expensive - assuming you can find them.

Prior to 1991, all vacuum cleaners used paper filter bags, which had to be constantly replaced until Dyson invented the bagless vacuum. Today, nearly every major projector brand except for Epson uses sealed laser projector engines that don’t require paper filters.  Older LCD projectors that still use filters have issues you need to consider for use in projector mapping. Here are some of the problems with filters.

If you dig into some of the older LCD projector models with filters, you’ll find that many models required filter cleaning every 100 hours.  While the filters themselves on a modern projector may last 20,000 hours, they still need to be cleaned regularly, and if you don’t clean the filter, the projector can overheat.  Plus, many projection mapping applications are outside, they will attract more dust causing you to have to clean the filters more often. Replacement filters can run as high as $60 depending on the model.

If dust or any of these other things gets into the innards of an LCD projector and ends up on one of the panels, it can create a blob that ruins the realism of your projector map. Trying to clean off a dust blob is not an inexpensive task, and the warranty language of many LCD projectors is voided if the unit is exposed to any of these items. Many used LCD projectors also have warranty exclusions for exposure to dust and smoke, which can damage the projector. This is why every BenQ projector used for projector mapping has a sealed light engine.

Figure – LCD Projector Turning Yellow vs. BenQ LH850ST Delivering Color Accuracy

Most new projector buyers are unaware that some LCD projectors are at risk of having the picture turn yellow over time. How big of an issue is this? It’s an ongoing topic in the Projector Central Commercial projector and home theater forums where the projector turns yellow.  According to Digital Cinema report, the loss of color accuracy over time was the primary reason that Sony exited the digital cinema projector market. In February 2025, the Holiday Projection Mapping Facebook group also had a post on an LCD laser projector less than five years old that had turned yellow.  While we can’t tell you which projector models will turn yellow, all BenQ projectors use DLP technology that has been proven in thousands of digital cinemas around the world never to turn yellow.

BenQ offers a variety of factory refurbished projectors that come with a warranty and free shipping. In 2025, there are new lower cost newer models designed specifically for home and haunted house projector mapping that are under $2000. For example, the BenQ LH850ST is a 4000-lumen projector that can map a 30-foot-wide home or building from under 15 feet away.  The projector is rated for 24/7 use, has a sealed laser engine, and is one of the only 4000 lumen projectors that have Rec. 709 color accuracy, which ensures realism when you’re mapping textures like grass and wood in your videos.  The projector has a three-year warranty and costs $1899.