The biggest rumor so far about this year’s iPhone 7, expected in the fall, is that it will have two camera lenses on its back.

Among various design changes, the new iPhone will reportedly lose its rear camera “bump” and it’ll get two cameras on its rear instead of one, according to MacRumors. Samples of twin-lens units have already been dispatched to Apple from its main camera suppliers, it is alleged.

This isn’t some techno craziness—it’s backed up by patents and precedent. Apple has been working on this technology for some time.

One Apple patent application describes two camera units next to each other, each with a very different purpose: One captures only information about the brightness in the scene you’re snapping, the other captures only the color information in the scene. By simplifying the design like this, you don’t lose quality, compared to a traditional camera sensor that does both these sensing tasks at once. The patent explicitly states that this lets you create thinner camera hardware—an attractive trait.

But it’s also possible Apple isn’t just pursuing aesthetic improvements with twin cameras. In April 2015, Apple spent $20 million buying a small technology firm called LinX (paywall). This was an Israeli company that built “miniature multi-aperture cameras designed for mobile devices.” LinX’s technology allows cameras to have better low-light performance, because there are two sensors trying to gather as much light information as possible. A similar improved sensitivity to contrast also happens in bright images.

Interestingly, LinX’s sensors also give smartphones the ability to capture depth information, because just like your human eyes, they see a scene in stereo. Remember the enormous momentum behind 3D imaging technology and the push for virtual reality and augmented reality—all of which benefit from 3D image capturing—and you’ll see why this could be interesting to Apple.

Lastly, check out the twin camera technology created by Corephotonics, another Israeli company. One implementation of Corephotonics’ system allows focusing of photos after they’ve been snapped (a bit like the amazing Lytro cameras). And Corephotonics’ tech also allows something much more interesting: Detailed optical zoom in photos and video. No one is saying Corephotonics is supplying hardware to Apple, but note that the company’s system also uses a similar brightness/color lens solution to Apple’s patent.

Every single one of these features sounds like something Apple would try and sell to its buying public: Slimmer phones with better camera sensors that capture better low light images, optical zoom for better control over your images and better photo quality, plus possibly 3D image capture. (Remember that the iPhone is still the most popular camera in the world, according to Flickr.)

That doesn’t mean we’ll see it in this year’s iPhone, though. This week, Sony CFO Kenichiro Yoshida explained that he thinks we’ll see twin-lens phones take off in 2017, not this year. (Sony has reportedly long been one of Apple’s camera suppliers.) And there were plenty of twin-lens rumors about the iPhone 6S. On the other hand, Apple does like to lead the pack, sometimes.