It may seem surprising, but the most popular cameras in the world are not made by Canon or Nikon. They're made by Apple—at least if Flickr's data is to be believed.
But a recently filed patent hints that future iPhones could borrow a key feature from traditional DSLRs: interchangeable lenses.
A filing from the US Patent Office website submitted on behalf of Apple shows a device that looks an awful lot like an iPhone sporting a metal bayonet mount—the same kind used by DSLRs—that would allow you to attach add-on lenses.
There are few firm details in the filing, as you'd expect, but it's a thorough presentation of what could be an interesting idea for the future. Apple has previously filed patents that used magnets to attach lenses to iPhones, so this patent hardly breaks new ground.
Interestingly, this filing specifically cites the problems with a magnetic mount: that it may be unsightly, may result in mis-aligned lenses, and may not hold lenses securely in place while running or walking.
But if a bayonet mount is the way to go, how exactly would such a device work? There are two ways we can conceive of, based on the details revealed in the filing.
The first and most obvious method would have the bayonet mount encircle a traditional smartphone camera/lens module. This would let you attach add-on glass on top of the iPhone's existing lenses. The mount would simply serve to keep the combo steady and properly aligned—essentially a first-party answer to third-party products like the Olloclip. Add-on lenses of this type could provide macro capability, a fisheye perspective, or extended telephoto reach.
The second and perhaps more exciting possibility would be something more like a true DSLR. In this case, the iPhone would come with a removable "kit" lens that you could replace with add-on lenses. The kit lens would likely be similar if not identical to the 4.1mm f/2.2 lens that's built into the current iPhone 5s. The advantage of making the original lens removable is that you could conceivably add lenses with zoom functionality, or brighter apertures for better image quality in dim light.
The patented design also includes an interesting wrinkle: The add-on lenses would lock firmly into place, but immediately detach if the phone were dropped on the ground. In theory, this would keep the lens from deforming on impact and destroying the entire camera. A broken accessory lens is better than a broken phone, after all.
It's important to note that all of this is speculation, and it's quite possible that this concept will never see the light of day. Probable, even. After all, the patent office is a graveyard of fascinating ideas that never came to fruition.
Still, camera quality is a major differentiator in the fiercely competitive smartphone market. Apple's iPhones may be stealing market share from traditional cameras, but it appears traditional cameras still have a thing or two to teach Apple.