Lume Pad brings back glasses-free 3D -- this time on an Android tablet

The Lume Pad's light field display can switch between 2D and 3D modes.

Scott Stein/CNET

Pillars stretch up and through the screen as I play a game on the tablet sitting in my lap. It's impossible not to think of the Nintendo 3DS. All glasses-free 3D tech makes me feel this way. The point is: Glasses-free 3D isn't new. It's been tried several times before, and it's still struggling to prove a purpose. A new Android tablet with a light field 3D display reminds me of that yett again.

With

virtual reality headsets

already here, but augmented reality glasses still not a thing yet outside of a few expensive business devices, the idea of glasses-free autostereoscopic 3D presents something of a stopgap: See holograms without a headset, or look at 3D objects in ways that are more... well, three-dimensional. There are already a few dedicated light field displays from companies like

Sony

and

Looking Glass Factory

. Leia Inc's

Lume Pad

is aiming to take the tech to tablets and other devices, too.

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The Lume Pad is an Android tablet that brings the glasses-free 3D idea back for $700 ($650 at the moment with a temporary discount from Leia Inc, the tablet's manufacturer). Do you remember the

Red Hydrogen One

phone? That had glasses-free 3D too, powered by the same tech from the same company. (Leia Inc. was part of HP Labs until 2014.) The tech bounces light off angled surfaces under the regular display to achieve the 3D effect. Much like the Red phone, the display can snap between its 3D mode and a regular 2D display. The light field display is using a more refined version of tech that was on the Red phone in a larger viewing area. It still has limited viewing angles, though, much like the old

Nintendo 3DS

(which used different tech), or even old lenticular 3D posters and postcards that have been around for decades.

The Lume Pad showing off a 3D pumpkin: I see it in 3D, but you can't see that here.

Scott Stein/CNET

The best thing about the display, as CNET's Patrick Holland felt about that Red phone back in 2018, is that it reverts to a standard 2D display. The Lume Tablet has a 10.8-inch screen with a 2,560x1,600 resolution, and looks absolutely normal in 2D mode. When playing 3D games or videos downloaded from the Lume Pad's 3D-dedicated Leia app store, however, the display shifts into its light field 3D mode (called "4V" by Leia). The backlight shifts a bit, and the resolution drops to accommodate the 3D effects, much like other light field displays or an old 3DTV display, which also reduced the resolution of 3D content to achieve that 3D effect. The Lume Pad uses the same 3D app ecosystem as the Red Hydrogen One does, but there's not much else that can tap in yet (although the tablet can convert 3D uploads in Sketchfab and could convert depth-mapped lidar photos from the iPhone).

3D effects can be tiled a bit to see the effect at different angles, but in a very limited way. Lean too far over, and the image will repeat itself and have that weird doubling effect that those old 3D postcards (or the 3DS) had when you moved too far off-angle. Sometimes the effect can be stunning, other times underwhelming. (There's a 3D effect slider that can increase the depth effect somewhat, and the effect seems better when backing the tablet off a couple of feet from my face.)

The Lume Pad has its own 3D rear camera for taking your own photos and videos (which looked...not stellar).

Scott Stein/CNET

While the Lume Pad does put the 3D effects into a standard tablet, the effects didn't appear quite as stunning as unique as when I looked at the Looking Glass' glass tank-like depth effects a few years ago. They're intriguing, but I really don't expect I'd use the 3D effects very much.

Patrick Holland said the Red Hydrogen One's tech had a "the paint isn't quite dry yet" feel to it back in 2018. It's 2021, and the Lume Pad still has that feeling. Although the tech absolutely works, I can't really explain why you'd ever need it. The tablet's $650 price is a lot less than the Red phone, but it's still a premium over other

standard Android tablets

(it comes in close to the price of Samsung Galaxy Tab S6). The Lume Pad does have a Snapdragon 845 processor, and 128GB of storage. It seems like a nice enough tablet, but the 3D part, which is its key feature, does not essential at all.

Part of that also has to do with glasses-free 3D's current incompatibility with augmented reality. AR effects, like those on

Apple's iPhones or iPads

, or Google's ARCore-supported phones, map the real world and layer graphics on top -- in 2D, but looking like they're really there on the phone screen. There are no glasses-free 3D ways of experiencing those AR apps and effects, and it makes the Lume Pad's features feel removed from the tools I'd normally use in AR (shopping apps, for instance, or measuring tools).

Lume Pad's Leia app store and installed 3D apps give you a bunch of things to do (and games), if you're looking for things to try on the tablet. It also supports Google Play.

Scott Stein/CNET

The Lume Pad can take its own 3D photos and video with its rear cameras, or convert photos and videos taken on the tablet into 3D, or convert YouTube videos or other photos taken elsewhere. The conversion effects are weird and artificial-looking. And the 3D effects aren't that poppy, often: maybe it's the tablet's design, or the software, but the depth levels often felt uninspiring.

I guess that's the thing. After looking at 3D video after 3D video, educational 3D diagrams on the educational app Mozaik 3D preloaded on my review unit, or 3D models from Sketchfab that I can play with, I wonder: Why? If I really wanted to explore 3D in depth, I'd wear a VR headset. If I wanted to think about 3D models in relation to the real world, I'd use AR. Meanwhile, this 3D tablet leaves me right in the middle of nowhere. What makes VR and AR headsets (or AR-ready phones) compelling is 3D

while moving through space

. Glasses-free 3D displays just assume you'll be sitting still. That's the 3D TV proposition all over again.

It's fun to see glasses-free 3D evolving a bit, but the tech also doesn't have very many places to go. It already failed in gaming laptops a decade ago. Maybe, for some reason, a car dashboard. But the world of 3D objects and scans of objects and products doesn't map in a useful way here. I do think about what a little glass window that shows me virtual things could offer me, but I can't offer good answers yet. My kid thinks it's cool -- for a while. Then he walks off and does something else.