LG CineBeam S Review: Minimalist Design Meets 4K Excellence

The LG CineBeam S — known on spec sheets as the PU615U — reimagines the ultra-short-throw projector as a lifestyle object: a compact, genuinely portable box that throws a 100-inch 4K picture from just 56 centimetres away from the wall, and a 40-inch one from a mere 23 centimetres. Inside sits a triple-laser light source rated for 20,000 hours behind a pixel-shifting 4K DLP engine, and measured results published in January 2026 finds a projector of real strengths and equally clear limits — one that earns its place for a specific kind of buyer.

The test's headline finding is contrast. Blacks stay deep across the vast majority of scenes — even bright ones — which gives films a solidity most compact projectors cannot manage, and the triple-laser engine produces what testers called an amazing colour gamut, delivering a genuinely vibrant image with richly graded and animated material.

The equally headline limitation is brightness. At a rated 500 ANSI lumens the CineBeam S is too dim to fight ambient light, and the test's recommendation is unambiguous: use it in a dark room with the curtains drawn, where its contrast and colour do their best work. Out of the box, white balance and colour mapping measured poorly — calibration is strongly advised, after which accuracy becomes very good. One further omission for film enthusiasts: there is no Dolby Vision support, though HDR content is otherwise handled.

The test is blunt on this point: gaming caps out at 60 hertz and input lag measured awful, producing a frustrating experience even in slow-paced titles. Anyone whose projector doubles as a games display should look elsewhere — the test's own comparison points to the Hisense PT1, which pairs similar ultra-short-throw contrast with genuinely low input lag at up to 240 hertz, as the gamer's alternative in this category.

What the CineBeam S offers that conventional ultra-short-throw hardware does not is freedom of movement. It is very compact and lightweight for its class, easy to carry from room to room, and setup takes care of itself: auto-focus and auto-keystone square the image up, and a wall-colour adaptation feature adjusts the picture's hue when projecting onto a painted wall rather than a screen. There is no internal battery — it must stay plugged in via its 65-watt USB-C power adapter — but the two USB-C ports double as display inputs for external devices, alongside a single HDMI 2.0 port with eARC for sending audio to a soundbar or AV receiver.

The software side is self-sufficient: LG's webOS runs Disney+, Netflix, Prime Video and the other major apps natively, with AirPlay 2 and Miracast casting on top. The built-in speakers are a token 2×4 watts — fine for a news bulletin, not for film night — but Bluetooth output to speakers and soundbars is supported and, given the eARC port, easy to upgrade properly.

Within LG's own line-up, the CineBeam Q is the near-identical sibling: the same impressive contrast, wide gamut, post-calibration accuracy — and the same disappointing brightness and gaming lag — with the practical difference that the Q is a conventional short-throw with plain ARC, while the S is a true ultra-short-throw with eARC. Against the wider field, the test positions the CineBeam S as the entry ticket to ultra-short-throw projection without typical ultra-short-throw prices; buyers wanting more brightness and gaming ability from the same format should step up to the Hisense PT1, and those prioritising portability above the wall-hugging format should consider the CineBeam Q instead.

The CineBeam S succeeds at exactly what it sets out to be: the smallest, most liveable route into big-picture ultra-short-throw projection, with class-leading contrast and colour for the money. Its constraints are structural rather than flaws of execution — 500 lumens dictates a darkened room, the out-of-box tuning demands calibration, and gamers are simply not the audience. As a second-room cinema, a renter's big screen or a design object that happens to project 100 inches of 4K, it is an easy recommendation; as an only display in a bright living room, it is the wrong tool. Buy it for the dark.