All of the projectors we review at CNET go through the same testing process, which involves objective measurements and subjective subjective evaluation. I’ve been reviewing projectors for over 20 years and have used one (well, many over the years) as my primary “TV” ever since I started reviewing them. I’m also certified by the Imaging Science Foundation and trained by the National Institute of Standards and Technology to properly measure displays. I use specialized test equipment, including a C6 HDR5000 Colorimeter, a Minolta LS-100 Luminance Meter, and an AEMC CA813 Illumination Meter. The data is collected and summarized by Portrait Display’s Kalman Ultimate software. All projectors are initially set up using the most accurate color temperature and color modes. Test patterns sent from Portrait are then used to adjust various image settings using Videoforge Pro 8K to ensure the projector looks its best before being measured and evaluated. Contrast ratios are measured in either lamp or LED/laser and iris modes (where available). Once the projectors are fully set up and objectively measured, we watch a variety of content including TV, movies, and games, both with the projector on its own and side-by-side with two direct competitors.
With 4K projectors like the Portable and other home theater projectors, I look for three most important aspects of picture quality: contrast ratio, overall light output, and color reproduction. Contrast ratio is the most important part of any projector’s performance. It’s the difference between the darkest part of an image and the brightest. While certain TV technologies like OLED can produce black, which is the actual absence of light, no projector technology can do that. That’s why a projector’s contrast ratio is much lower. It’s the difference between a washed-out and “flat” image and one that’s more vibrant and “pops.” Better projectors will have a contrast ratio measured in the thousands. Most are between 500 and 1000:1. The average contrast ratio for all projectors we’ve measured in the past few years is 468:1, and the average achieved by several high-priced projectors is 876:1. Total light output, measured in lumens, is not just how bright the image is, but how big you can make it and still have a viewable image. A few lumens difference doesn’t matter, but a few hundred can be the difference between a dull, boring image and one that really pops. Color is a tricky subject, but after years of testing, including dozens of “faces” with both non-saturated and non-saturated viewers, accurate color almost always wins out over oversaturated or undersaturated colors. The most accurate projectors produce vibrant colors that are very natural to look at.
Light output is the second most important factor, as it’s not just how bright the image appears on your wall, but also how big of an image you can create. Most modern projectors are significantly brighter than projectors from even 10 years ago. We measure brightness in candelabra per square meter (cd/m2) and then convert that to calculated lumens for ease of comparison. It’s important to note that we use the most accurate color temperature mode for our brightness comparisons, but we’ll note when a less accurate mode is significantly brighter. Most projectors we test are between 1,000 and 2,000 lumens, with battery-powered models going much lower, and some specialty projectors going even higher. The average brightness for projectors we’ve measured in recent years is 901 lumens.
Color accuracy is the final key factor. No projector can truly take advantage of HDR, Dolby Vision, or wide color gamut, but some can do more than others. We’re generally happy with accurate colors, but the addition of HDR effects is a bonus. Most home theater projectors we test are pretty accurate. Budget models, those that prioritize brightness over everything else, and devices ranging from newcomers to the projector space often have wildly inaccurate colors, resulting in a very unnatural image.
Viewing tests evaluate other factors, such as video processing and HDR processing. This is rarely the main factor in a projector’s performance, but some models still use older chips that have issues.
The best projector will have a high contrast ratio, high brightness, and great color. These are hard to do at the same time, but as long as the balance works and it looks better than its similarly priced competitors, it’s a winner.
For more information, check out How CNET Tests Projectors in the Area.
