Ultra-short-distance Beamer LG HF85JS with laser light

At 20 cm distance, project a 3-meter image on the wall? No problem for the ultra short throw Beamer LG HF85JS – and then the picture looks good too.

Where classic projectors often need several meters to produce a large picture, short-throw projectors often have a meter or less thanks to the wide-angle lens. Ultra-short-distance projectors such as the LG HF85JS go one step further. They radiate the image backwards from a wide-angle lens and reflect it back onto the projection surface via a curved mirror. Thus, they create images of several meters in the diagonal at only a few centimeters distance to the (linen) wall. At least the manufacturers promise that. And what does the practice say?

The distance to the wall is only a few centimeters.

The LG HF85JS needs only a few inches of distance to the wall to create an immensely large image? Right. At a minimum distance of 8 cm from the wall, the I-shaped projector with a length of about 35 cm protrudes just 43 cm in depth. A sideboard should be at least as deep, which is usually not a problem.

The minimum distance of 8 cm makes sense, because on the one hand there are the connections for power, picture and sound on the back, which naturally need some space with the cables plugged in. On the other hand, a fan removes the waste heat from the bulb backwards to the wall. This should not be covered so as not to adversely affect the life of the luminaire.

LG achieves the very high projection ratio via a wide-angle lens in combination with a curved mirror.

LG indicates a 229 cm (90 inch) diagonal image at a distance of 8 cm. At a distance of 20 cm, the diagonal increases to 305 cm (120 inches). In the test, this information is confirmed. If the HF85JS is 30 cm away from the wall, the image size even increases to 360 cm (about 140 inches).

This small distance from the wall with a large picture at the same time offers another advantage in addition to saving space: A person does not throw any disturbing shadows over the picture when passing by or standing in front of them.

The feet on the bottom come with a thread.

In the options LG offers the possibility to mirror the picture vertically and horizontally. Buyers can also use the ultra-short throw beamer for rear projection or mount it on a ceiling. Therefor it offers four threads on its underside, the actual holder for the ceiling is available as an accessory.

The LG HF85JS has no mechanical lens adjustment, also called lens shift. He can only compensate digitally for distortions due to an oblique projection. The cut off surface accordingly reduces the resolution accordingly. With a little sensitivity and patience, he was always put up in the test so that he threw a straight picture on the surface and nothing had to be digitally cut off.

The small lever on the focus wheel broke off during transport.

A mechanical wheel on the top of the beamer sets the focus. However, a small lever attached to the wheel broke off during transport. Without tools, the focus can not be adjusted anymore. Here LG should have chosen a more stable solution, because a transport bag is not included in the projector.

In the test we noticed a problem, which concerns especially ultra-short-distance beamer. Due to the very acute projection angle even small bumps of the wall or the screen lead to significant distortions in the image.

LG promises a brightness of 1500 ansi-lumens. That is not enough to use in bright rooms, for example at conferences. For a usable image he needs at least a slightly darkened room. In the test, the quality of the colors and the intensity of the contrast diminished slightly when dimmed evening lighting in the living room lighted up the screen slightly. But even the eye gets used to it quickly. Especially when the projection diagonal is only 229 cm (90 inches), that hardly bothers in practice.

At 360 cm (140 inches) in the diagonal, we clearly recommend a completely darkened room. Advantage of the design: With a wave of the hand you move the projector only a few inches and changed in no time the image size. Nevertheless, as with all home cinema projectors, the picture only shows its full potential in rooms that are completely darkened and therefore only serves as a full replacement for a TV in individual cases.

The HF85JS is not based on conventional UHP lamp technology but relies on a laser module. Several small laser diodes are detected by small mirrors and bundled into a large beam of light. The rest of the projector is based on the widely used DLP technology. The light is reflected through a DMD chip (Digital Micromirroring Device) from Texas Instruments over 2.2 million mechanical mirrors – one for each pixel – towards the lens, if the pixel is to shine – or not. This happens so fast that the DMD chip generates up to 1024 gray levels. As with conventional DLP projectors, the colors are handled by a fast-rotating color wheel, which colors the laser light accordingly.

Advantage of the DLP technology: It works reliably and enables a compact design of the beamer. However, it also leads to the so-called bead-string effect in some viewers: If a spectator moves his eyes quickly back and forth in the picture, the inertia of the receptors in the eye leads to a rainbow effect. Depending on the audience, this effect is perceived as more or less disturbing. In the test, we took the effect in the first few minutes clearly true, then only if we pay attention to it.

The LG HF85JS dissipates the heat to the rear.

The laser technique has several advantages. For one thing, the picture is immediately there when you turn it on. Thanks to the low heat loss, the fan is quieter than with projectors with UHP lamp and hardly interferes with the operation. After switching off, it does not run, the device is immediately shut down. In the test at a movie night, the fan noise was audible in quiet passages, comparable to a notebook under full load. However, since a screen diagonal of two to three meters is usually located several meters away from the image, it does not interfere in practice. At the latest, if it goes in the movie a bit louder, you take the fan noise is not true.

The laser module also provides long-term stable light output with moderate power consumption. LG states that the light output is still 80 percent after just under 10,000 operating hours, and 60 percent of the original brightness after 20,000 operating hours. Converted to the laser module so after almost 2.3 years in continuous operation still deliver 60 percent light output, which corresponds to about 10 times the life expectancy of a conventional UHP lamp.

The rainbow pattern in the picture was actually seen as a so-called pearl string effect.

The LG HF85JS offers a native Full HD resolution of 1920 × 1080 pixels and a very good on the paper contrast ratio of 150,000: 1. We were very impressed by the quality of the picture in terms of its colors and contrast. The illumination is also uniform, individual halos are hard to make out. Even if the room is completely darkened, the full HD image does not match the quality of a current TV set in terms of contrast and color intensity, but it does offer a very decent result. But even if the contrast ratio is very good for a projector, black spots are not really black. This is especially noticeable in dark movie passages. For a bright picture, on the other hand, the presentation looks almost brilliant.

However, we would have liked in a picture with over 3 m in the diagonal, a 4K or UHD support. Especially because in recent months UHD upscaling of Full HD beamers, especially in the entry level, is becoming increasingly widespread, see our market overview of 4K projectors . The technically and competitively priced Xiaomi Mi Ultra Short Distance Beamer integrates UHD upscaling. In a few weeks we will also test it in detail and compare it with the LG HF85JS.

The quality of the projection improves with the use of a projection screen. When making a purchase, you should pay attention to a short-distance projector screen. It reflects the light from the projector towards the spectators and lateral incident light in a different direction. This increases the contrast of the projection.

The sound of the 2 × 3 watt speakers installed in the LG HF85JS disappointed. Contrary to the LG advertising promise, they sound flat and virtually no depth. However, the projector comes with many connectivity options for external speakers. In addition to the classic 3.5 mm jack, an optical output, Bluetooth and HDMI ARC (Audio Return Channel) are available.

Similar to TVs, some projectors also have their own operating system and corresponding smart features. The LG HF85JS relies on WebOS version 3.0. Run on apps like Netflix, Amazon Instant Video, Maxdome, Dazn and Sky Ticket. The LG App Store adds many applications later when needed. However, the selection is not complete, we miss providers such as Youtube or the ZDF media library.

Picture: LGgraph of WebOS 3.0.

Visually, WebOS 3.0 makes a very good impression. When pressing the Home button on the remote control, the last used apps at the bottom of the screen line up like small tabs, while the currently used app continues to run. The arrow keys on the remote control navigate self-explanatory through the apps. In addition to videos, pictures and music, the projector can also play Powerpoint, Word or Excel directly from a USB stick.

The remote control comes with a clever touch: On request, it controls a pointer over the screen by hand movements like a computer mouse used in the air. This works after a short familiarization comparable to the Wii Remote of the Nintendo Wii and makes it particularly easy to enter usernames and passwords on the virtual keyboard.

We are disappointed with the speed. Although the beamer is ready to use in a few seconds when you turn it on, but he allows himself for each additional action sometimes several seconds thinking time until he executes them. We expected that from a device in this price range differently. If you want a larger app selection with a fast response time, you should opt for external streaming solutions such as the Amazon Fire TV Stick, Chromecast, Apple TV or similar.

The LG HF85JS costs around 1900 Euro at the time of the test. However, the price history shows that he was temporarily available for 1650 euros. We recommend interested parties to set a price alert in our price comparison , who then sends an e-mail undercutting the set price mark.

The LG HF85JS projects with only 8 cm wall distance a 229 cm (90 inches) and very nice Full HD image on the wall or screen. The laser optics survives conventional UHP luminaires by a factor of ten, consumes less power and keeps the fan relatively quiet thanks to lower waste heat.

The operating system WebOS 3.0 looks good and self-explanatory. However, some apps are missing and also the reaction speed tempts to yawn. We have hoped for a device in this price range faster. We would also like to have seen in the projector 4K upscaling (market overview) . Corresponding devices are sometimes already under 1000 € to have.

The Xiaomi Mi Ultra Short Distance Beamer builds on a similar technique, costs a similar amount, but offers 4K upscaling. In the next few weeks, we will also take a closer look at it and compare it to the good LG HF85JS.

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