Accessory lenses for smartphones can be useful tools for expanding the photographic capabilities of your device. However, the process of physically attaching these lenses to the smartphone and centering them above the camera lens is prone to minor but important error as even a slight misalignment can result in a drop in image quality. Additionally, the accessory lens' optical design can have a detrimental effect on the image output.

Apple has now been granted a patent that aims to fix the problem using a two-pronged approach: by using correction software and a movable built-in camera lens.

The document describes camera hardware and an analysis and processing software that can be used to analyze image quality and detect problems potentially caused by add-on lenses. By looking at certain image metrics, the system could compare image quality before and after attaching an accessory lens and then use software algorithms to correct accordingly.

Additionally, actuators would allow to change the position of the built-in camera lens on multiple axes, in order to correct for any misalignment of the accessory lens. This could include tilting the camera and varying the distance between the built-in lens and accessory lens.

The patent suggests electronics, magnets and radio sensing among other methods to detect if an accessory lens has been attached. If the smartphone knows what exact accessory is being used, additional options in the camera app could be utilized as well.

As usual, there is no way of knowing if and when this system will make it into a production device but it certainly looks like it could make the use of accessory lenses more appealing to many of us.

You can find the complete patent document on the USPTO website.