All display systems, even 1ms gaming monitors, have some degree of input lag. However, the performance of today's gaming projectors is constantly improving. As gaming projectors become faster, input lag becomes less and less significant. 

For serious gamers, success boils down to the split-second decisions you make on the fly. Because of this, gamers need to ensure that nothing gets in the way of their decision making, including the gear they use for their gaming setup. From accessories to hardware, hardcore gamers are already accustomed to seeking out the highest performing equipment they can find, and the same goes for their display solutions. 

When it comes to gamers who are looking for more immersive experiences though, there has been a growing movement away from traditional TVs/displays in favor of gaming projectors. For these gamers, when looking for the ideal projector one of the main criteria used to judge the performance of a projector is its input lag.

But what exactly is input lag? How do you measure input lag on a projector? How can you reduce input lag on your projector? Is input lag the be-all and end-all for judging the performance of a projector? These are the questions this article will seek to answer.

What is gaming input lag?

Input lag, or latency, for projectors refers to the time between an action being taken by a player and that action taking place visibly on screen, which if too long can cause things such as lag or the feeling that the game and the display are out of sync. Because of this phenomenon and how it may affect your ability to play at the highest level, low input lag is one of the key things to focus on when determining whether a projector will boost or hamper your gaming abilities, as you want a projector that instantaneously projects the video that the console is transmitting to it, so as to make sure that you’re able to make those split second decisions.

It’s worth noting that input lag is different from response time, even if the terms are often used interchangeably. Response time in gaming refers to the speed with which a display device like a monitor, TV, or projector updates or changes pixels, or more accurately the color of pixels. Input lag is the total time between an action taken by a player, like pressing a button on a controller, and that action being depicted or acted upon on-screen. 

With an understanding of what input lag is, the next step is to figure out how input lag is measured and how this knowledge can be applied to choosing a gaming projector. For most gaming projectors, input lag time is listed in the product specs using milliseconds (ms) as the unit of measurement, so for a projector with a listed input lag time of 16ms there will be a 16 millisecond gap between when the signal from the gaming console is received by the projector and when the resulting image is projected. For some this may seem like just a sliver of time, but for more demanding gamers it could be a matter of life or death (figuratively of course). The calculations used to derive the value itself are a result of the projector’s resolution and refresh rate, along with the engineering of the projector. As a result, most specs that list input lag also list the conditions in which that value was measured, including resolution, refresh rate, and any corresponding video modes used, all of which gamers should take into consideration when comparing projectors.

Likewise, refresh rate, or refresh frequency, is another useful concept when judging the performance of a projector. Strictly speaking, refresh rate is the rate at which a projector showcases images or frames in a video broadcast. You can think of it as essentially the frame rate for a projected video, or the number of frames per second. Whereas frame rate is usually measured in frames per second (FPS), refresh rate is measured in hertz (Hz), but they are the same thing. So, in other words, a projector with a refresh rate of 120Hz projects 120 frames every second. Refresh rate is an important measure for a projector’s performance because a higher refresh rate, i.e. a greater number of frames projected per second, means video with cleaner, smoother motion and less blur.

Given the knowledge of how input lag is measured and how it can be identified in a projector’s specifications, how then is a user supposed to ensure that the projector they’ve purchased achieves the input lag advertised in its specs? A sizeable amount of gaming projectors on the market feature a pre-configured fast mode that helps reduce input lag when enabled. It’s recommended that when shopping for a projector, gamers double check to see if their prospective purchase features such a mode, and once purchased that they activate the mode prior to gaming. Beyond that, it is also highly recommended that gamers further boost their projector’s speed by turning off any image processing functions such as keystoning, aspect ratio manipulations, and overscanning. Doing this will further complement the fast mode feature and ensure that your projector is working at its fastest speed possible.

There’s a very simple answer to this big question, and it’s a yes. DLP technology provides much more responsive gaming than LCD projectors. DLP reduces the amount of processing required to project an image, resulting in less lag and total input latency. Since lag and latency present the most obvious obstacle to gaming enjoyment, this is a big win for DLP projectors. LCD projectors suffer from greater lag due to their additional image processing steps. By comparison, DLP gets as close as possible to 0ms response.

As a rule of gaming, the higher the refresh rate, the more responsive games feel to players, regardless of resolution. Also, higher refresh rates bring lower input lag. But when comparing DLP and LCD projectors, we find that the input lag reduction isn’t as strong on the LCD side and doesn’t scale the same way. A clear example of this is DLP gaming projectors delivering 1080p 120Hz with 8ms input lag, while comparable LCD projectors do the same resolution and refresh rate at 18ms input lag. That’s a big difference. For 4K 60Hz, DLP offers 16ms, while LCD can only manage 19ms. DLP also provides 1080p 240Hz at just 4ms, which isn’t possible with LCD projector technology.

As an indication of DLP being better for gaming, the benefit of higher refresh rate is much clearer on DLP than it is on LCD projectors.

Note: test results is reviewed by Projector Central.

Beyond the discussion above regarding input lag, there are also plenty of other considerations to make when purchasing a gaming projector, especially if you are doing so in order to create a more immersive gaming experience. This includes attention towards color accuracy, overall image quality, and rendering of details by the projector. For BenQ this has led to the development of our suite of gaming features. BenQ gaming series projectors combine features such as special video/sound modes and detail adjustments designed specifically for different gaming genres, coupled with a high performance fast mode that reduces input lag to a minimum. 

An important addendum to this discussion is a note to gamers that brands which advertise projectors with 4K resolution and a 240Hz refresh rate are promoting misleading claims. Such claims are misleading because these projectors are not actually able to produce native 4K 240Hz. Whereas these projectors do have the capacity to provide 4K resolution, their hardware is only able to reach a 240Hz refresh rate when the resolution is downgraded to 1080p FHD, so the labelling of 4K and 240Hz side-by-side with is a misnomer meant to attract attention. Another related item to note is the fact that as of now no gaming consoles are able to output 240Hz content, so to purchase a projector with 240Hz refresh rate capabilities for gaming purposes is to spend extra for something that might not be used for years, unless you intend to connect your gaming projector to PC and enjoy 1080p 240Hz gaming in stuff like CS:GO, Valorant, or Rainbow Six Siege.