The Epson EH-LS100 AV projector combines two unusual features in one projector: ultra-short-throw projection, and a laser-diode light source. The lasers deliver long life and low maintenance, while ultra-short-throw allows the projector to sit at the foot of (or close to and above) the projection screen. They use mirrors and some pretty magical optics to cast a picture that’s focused and of comparable brightness across its dimensions, despite the seemingly ludicrous positioning.

Equipment
In this case, for a 100-inch display in 16:9 aspect ratio, the projector needs to be located with its projection window just 610mm away from the screen. Since the projection window is actually near the back of the projector, its body is 260mm from the plane of the screen for that display.

UP CLOSE, UP HIGH:
four Epsons create the streetscape
view from Taipei 101,
formerly the world’s tallest building.

We have to specify the aspect ratio because this projector packs, rather than a full-HD display engine, a WUXGA engine. That’s 1920 pixels across by 1200 pixels tall, a format commonly used with computers and professional installations, and one that’s natively 16:10. Indeed, partway through our time with this projector, we spotted four LS100 projectors bolted to the ceiling on one of the upper floors of Taipei 101, formerly the tallest building in the world. They were displaying a very wide image on a wall (below right), and thanks to their short-throw nature, members of the public could interrupt the image only by purposely moving uncomfortably close to the wall.

That’s an advantage in the home as well. Instead of projecting an image across the room, to be interrupted by people within the room, the projector is at the front, up close to the screen. Having said that, this is not a portable or compact projector. It’s fairly large physically, and weighs a very solid 11 kilograms.

The other unusual feature is the laser diode light source. Epson says that this source makes for a lamp life of up to 20,000 hours normally, or even 30,000 hours if you choose the lamp-saving mode.

Even the shorter period works out to four hours a day every day for more than 13 years.

As the WUXGA resolution suggests, this is a multipurpose projector. Installations are one application, and it has an Ethernet connection for control, along with a USB Type-B socket for connecting to a computer. There are also two USB Type-A sockets for plugging in media for immediate playback. Plus, you can connect a Wi-Fi adaptor. Fun, we imagine, though we didn’t really dig into those features. Our focus here is on home theatre use, using one of the three HDMI inputs. And although natively 16:10 aspect ratio, the LS100 can be used in 16:9 mode. A band of 60 pixels at the top and 60 pixels at the bottom go unused in that mode.

Epson’s inorganic three-LCD panels are used to create the image. The projector itself is full-HD only, and would seem not to support HDR or wider colour systems, even though the panels themselves support ten bits of brightness resolution. Nor does it have HDCP2.2, required for use with Ultra-HD Blu-ray.

The projector has a mono audio capability with a 16-watt amplifier and a single speaker — again, of limited importance for home theatre where an external sound system should be used alongside.

Performance
Setting up is, as is usually the way with ultra-short-throw models, just a little finicky. It’s mostly to do with magnification. A very small move of the projector results in a large move of the image. Even after we aligned the image, we were disheartened to see the image crisp and well-defined down to the pixel level at the bottom (which was closest to the projector) but decidedly fuzzy up near the top.
A consultation with the manual soon sorted that out, pointing us to a focus lever hidden under a panel over the vent. This made for easy focusing of the top. Because of the way the image is cast — just a short distance to the screen area closest to the projector and quite a long way to the other side — the closer part is pretty much always in focus. So it’s the rest of the image you’re adjusting. And when we slid the lever to focus the top, the whole thing was extremely sharp.

Geometry was quite good. There was a very slight trapezoidal distortion on our projection screen, but it turned out that our screen was very slightly warped. We could get one side square, and the other side was slightly forwards at the bottom, a small variance from true vertical on that side. When we forced it square, that went away.

Remember, ultra-short-throw equals ultra-low tolerance for geometrical misalignments. But in general it will be installed properly, with a truly flat screen. We remain a little amazed at the optical abilities involved in producing a rectangular picture in such a way.

Also impressive was the uniformity of brightness across the picture. We have little doubt that we could probably measure differences, but to our eyes the top and bottom of the picture, the centre and edges, were all the same in brightness and colour intensity.

The projector implements a dynamic contrast ratio system, the idea being that in darker moments of the video the overall brightness can be reduced, allowing deeper blacks. (Remember, the human eye works by means of a dynamic iris too.) We’re weren’t absolutely certain if dynamic brightness was produced by a powered iris or by adjustments to the brightness of the lamp. But by flicking between dark and bright and dark scenes and seeing the blacks change in level as it did so, we think it was the lamp rather than an iris. There was none of the ‘chuffing’ noise that can be detected with the operation of a dynamic iris, and there was also a noticable delay — a good part of a second — between image brightness changes in the signal and those on the screen.

The native black levels were about the same level as you’d expect from, say, a respectable DLP projector. When we looked carefully, we could see in bright scenes that there was a fair bit of bleeding of light through to black areas. But in practice, in most scenes, the subjective impression was of decent black levels, simply by contrast with the bright areas of the picture. Say, about what you’d see at the cinema. But we wouldn’t say that the black levels were what we’d imagine from the claimed 2.5 million-to-1 contrast ratio.

Using pluge test patterns, we felt it best to drag the ‘brightness’ control from the default of 50 down to 47. But that was the only setting that needed adjustment. The colours were accurate and bright, and very natural.

The projector has no motion-smoothing algorithms. If a film is shot with a too-short shutter speed during pans, it’s going to look jerky as the pan is delivered to the screen. There is motion adaptive deinterlacing of 576i/50 and 1080i/50 video, along with auto detection of film or video source content. The latter was fairly mediocre by today’s standards, frequently misinterpreting film-source content as video-sourced in both formats. If possible, it would be best to deliver to this projector progressive-source material. That said, we happened to catch a part of the Australia versus France World Cup match with this projector, and the video-sourced handling there was first rate.

With a solid, weighty chassis and a lamp that is relatively low in heat production, even at full power the projector is not especially noisy. Put it into Cinema mode (rather than Bright Cinema), and the light level dropped almost imperceptibly while the fan noise reduced more significantly.

The fact that the projector is in the front of the room has the subjective effect of quietening it further, since that’s where the majority of the sound in most program material is coming from. Regular projectors tend to be above your head, slightly behind or forward of the viewing position, and the fact that they are not near the source of most of the program audio makes their noise more distinct.

Finally, laser light sources don’t take an age to warm up. This projector had its splash screen up in about eight seconds from switch on, and the image only a few seconds after that.

Conclusion
The Epson EH-LS100 is a very useful home theatre projector, with its long life and virtually zero maintenance requirements, while its ultra-short-throw design looks to us to make it an excellent fit for many a home.

Epson EH-LS100 ultra-short-throw projector
Price: $4499

+ Ideal for close placement
+ Ultra-long lamp life
+ Bright, bold image

- Blacks not quite up to Epson’s usual home theatre standards

Projection technology: 3 x 17.0mm Polysilicon TFT active matrix LCD panels
Resolution: 1920 by 1200 pixels
Aspect ratio: 16:9
Lamp: Up to 108 watt laser diode
Lamp life: ‘Up to about 20,000 hours’
(normal/quiet mode); ‘Up to about 30,000 hours’ (extended light source mode)
Contrast ratio: 2,500,000:1 (Dynamic)
Brightness: 4000 lumens
Zoom: Nil (optical); 1.35:1 (digital)
Inputs: 3 x HDMI (1 with MHL support), 1 x composite video, 1 x D-SUB15, 2 x USB-A, 1 x USB-B, 1 x stereo analogue audio
Outputs: 1 x D-SUB15 (passthrough from D-SUB15 input), 1 x stereo analogue audio
Other: Ethernet, slot for optional Wi-Fi module
Dimensions (whd): 494 x 172 x 437mm
Weight: 11.0kg