Since iPhone 4, camera experience on Apple phones was among the best in the industry. But it’s only so much you can do with the camera quality in such a tightly packed device as a smartphone. Physics/optics start to get in the way and you just run out of space to put the new bigger lenses, zooming capabilities or additional filters.
But Apple does have some ideas how to fix that: removable back covers, with optical elements integrated into them:
Described in the patent application “Back Panel for a Portable Electronic Device with Different Camera Lens Options”, such back covers can include:
IR-cut filter for capturing black and white images at very low light levels
a close up lens that reduces the minimum focal distance and permits the camera to be used for extreme close-up photography
lens baffle in combination with a supplementary lens to increase the focal length and reduce the field of view. The lens baffle is closely matched to the reduced field of view so that light that is outside the field of view is not reflected onto the image sensor to degrade the acquired image.
By integrating some control chips, additional elements and even small battery into removable cover, all connected to the main iPhone circuitry – the possibilities expand further. The optical element in the back panel can become:
the optical image stabilizer, which receives inputs from iPhone accelerometer and optically cancels movement effects
optical zoom assembly reacting to the touch gestures on iPhone display
a mechanical shutter providing better control of the exposure when taking pictures of e.g. quickly moving subjects
stroboscopic flash with it’s own power supply
If Apple ever introduces iPhone model with such removable back panel, this will usher in a whole new era of innovation in iPhone camera accessories. And will make iPhone one of the best amateur photography devices around.
The problem is – removable panel introduces a whole set of design, engineering and manufacturing issues. There are very good engineering reasons that every iPhone released yet – is a solid metal/plastic box, with no movable parts.
Whether new camera capabilities will ever be worth the trade-offs removable back cover requires, is not clear. And until those trade-offs become worth it to Apple – this new kind of photo iPhone will remain a fun R&D project.