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Why you might want a foldable Samsung Galaxy phone

Also, why you might not.

Josh Miller/CNET

Samsung's foldable phone for 2018 is pretty much a done deal -- the head of Samsung mobile said so -- but will you really want one?

That will depend, for one thing, on what we mean by "foldable." We've seen one Samsung patent application for a handset that bends at the middle so the top of the phone can touch the bottom. Yet it's the second patent application that seems much more likely to become an actual device, one that can open up to become a mini tablet.

This concept relies on two side-by-side screens that connect with hinges and unfold like a book. Samsung wouldn't be the first to advance this kind of design. In fact, the ZTE Axon M does the same thing, and is on sale now with US carrier AT&T.

Concepts and prototypes for flexible phones that twist, bend and unroll have appeared now and again (like this concept that wraps around your wrist like a watch), but before there are batteries and other internal parts flexible enough to bend like that, a design that evolves the traditional flip phone is much more practical.

Here's why you might want something like it -- and why you might not. 

Pros: Why you want a folding phone

There are at least three good reasons.

1. Double the screens in a compact shape

Doubling your screen space without supersizing your phone would be ideal, right?

That's why the current trend of phones with slim bezels and no buttons took off on the Samsung Galaxy S8, iPhone X and at least a dozen others. But this is small potatoes compared to doubling your screen real estate by adding another full-size display.

The hinge that connects the two panels is the design's secret weapon, because it lets you fold the second screen back on itself so your double-wide handset achieves the same height and width as a typical phone. Yes, it's double-thick too (see Cons below), but that's still a helluva lot more compact than carrying around a device with a 6.8-inch display.

Now playing: Watch this: ZTE Axon M is a quirky phone with double the display
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2. More cool things you can do

ZTE's Axon M gives us a taste of the possibilities, with four ways you can use the two screens:

  • You can use just a single screen. 
  • You can use both screens, each with a different app on it. 
  • You can have the same app on both screens. 
  • And you can use both screens as one big display.

We don't know for sure that Samsung's foldable phone would do the same, but it's likely, especially a full-screen mode that could introduce new ways to watch videos, play games and multitask. There's also the suggestion that Samsung's version could work with, or even come with, an S Pen stylus.

Patent drawings suggest that Samsung's foldable phone hinges will give you a 360-degree range of motion, where the Axon M screen won't budge beyond 180 degrees.

3. Better selfie camera

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What if your selfie camera were the only camera?

Josh Miller/CNET

We can't say what kind of camera setup Samsung would use, but let's just imagine for a moment that your selfies have the same crystal-clear focus, sharp, detailed edges and bokeh blur as photos taken through the rear lens.

That could be the case if the foldable phone gets rid of a dedicated selfie camera and uses one high-end lens for all your photo needs. 

For example, the ZTE Axon M's 20-megapixel camera uses one screen to take your selfies and the other to take all your other shots. (The camera faces you by default, and you're prompted to flip the phone over to take "rear camera" shots.)

The benefit here is that selfies could have a higher-than-usual resolution and look better in low-light scenarios. You'd also have access to all the same tools, like pro mode and a beauty filter. 

Cons: A folding phone is an awkward phone

This is not our first dual-screen rodeo. We've seen phones with screens on either side, with smaller ticker-style screens at the bottom or top, and designs with a touchscreen on the outside and a smaller display (and keyboard) on the inside. Most missed the mark.

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This design is rising from the dead.

Josh Miller/CNET

The one I want to point out was a spiritual precursor to the Axon M called the Kyocera Echo. It was a disaster, but an instructive one that warns us of the ways dual-screen phones can go wrong really fast.

1. Thick and heavy

This is the main worry. Unless each side is only a few millimeters deep -- which would require paper-thin batteries and other components -- you're looking at a double-thick phone.

It'll also be heavier than usual. The Axon M weighs 8.1 ounces (230 grams); most phones range from 5 ounces on the light side up to 7 ounces for a large, heavy device made of metal and glass. 

When you're slapping another screen on top of an entire phone, there's no getting around that.

2. More complexity means more ways to go wrong

A second screen. A hinge. Software that changes modes.

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One side of the Axon M is much thicker than the other.

Josh Miller/CNET

If these aren't spot-on, they run the risk of being distracting or hard to use. On the Axon M, just take a look at the black bezels and center hinge cutting right through the middle when you've got both screens open in extended mode.

Or the fact that the second screen becomes useless dead weight most of the time. Or that you have to flip the phone around to take selfies. And when you do unfold the screen, the side containing the battery is far thicker and heavier than the other, which feels weird and imbalanced.

The placement of camera lenses, ports and buttons are arguably more crucial on a device with an extra screen tethered to a working phone. If it's unwieldy and hard to use, or if one of those elements malfunctions -- a software bug in expanded mode or a loose hinge, for example -- you'll know, quick.

3. Potentially pricier

Generally, phones with more parts, custom parts or high-end parts cost more to build and therefore more to buy. Samsung would surely position a foldable phone as a premium or niche device (or both), which would help support a higher price.

ZTE's Axon M sells for $725 (about £540 or AU$950), which costs more than the starting price of both the top-tier iPhone 8 and Pixel 2. Yet ZTE's phone has last year's specs, which is asking a lot of anyone except the most niche early adopter.

Samsung would have to strike the right balance between price and hardware performance to avoid the Axon M's pitfalls.