Additionally (and slightly confusing) is this "Ambient Screen" setting on the Moto 360. Here's the thing, though: The ambient screen setting is turned off by default on the Moto 360, and there's a good reason for that.

After all, our phones can adjust their own brightness depending on the lighting conditions. Why not these watches? After all, it's all about saving on battery life, right? And displays are one of the biggest power draws on any mobile device.

Much has been said about the ambient light sensor on the Moto 360 leading up to its release. For one, it's part of the reason for the black bar at the bottom of the Moto 360's display. (Whether that bothers you is another discussion for another time.) And an ambient light sensor is one of those things many of thought was missing from the first few Android Wear releases.

You can turn on the ambient screen on the Moto 360 a couple ways: The first is to go into the Android Wear app, and hit the watch settings button. The other is to go into the settings on the watch itself. Doing so on the phone actually is a little quicker, but they both do the same thing.

Either way warns that turning on the ambient screen will be detrimental to battery life.

Out of the box, the screen on the 360 is on a timer of sorts. When you stop touching it or asking it to do something, it shuts off after a few seconds. When you raise your wrist or get a notification, the screen pops back on. That changes when you use the ambient setting.

With the setting enabled, instead of turning the screen off right away, it dims it down into a low power state. Eventually it will go dark, but it stays on much longer. That means it can use more battery juice to power the screen when the watch is sitting idle on your wrist doing nothing. And chances are, that's what any smartwatch does most of the time.

It works a little different than we expected, which was that the ambient sensor would automatically adjust the brightness and keep the same time-out settings — like it does on your smartphone —while using the same low-power display options we see in the G Watch or the Gear Live, where the screen dims but also switches states and drops things like color or second hands to be more miserly when it comes to the battery. We didn't expect a setting that toggles the screen-on time, using the term "ambient," that was disconnected from the actual sensor.

Trade-offs, don'tcha know.

Editor's note: We apologize for the early confusion. We're talking about the setting that keeps the screen enabled here, and any differences it may make in the time between charging. We'll talk about how the ambient light sensor doesn't work as we expect to maximize battery life with a separate low-power state like we see in other Android Wear devices in a future post.