Optical zoom is widely used in photography. It is highly desirable for framing a picture and for exploiting the entire image sensor for the objects of interest and is available in every DSCs and DSLRs. Opto-mechanical zoom cameras are capable of dynamically changing the focal length of the lens and the captured field of view. However, zoom lenses are bulky, with many lens elements and several lens groups. They are more susceptible to drop and are typically characterized by an increase of the F/# as the zoom increases, which limits the attainable resolution. The impact on the size and the weight of the camera module makes it unsuitable for mobile photography, where in fact, the vast majority of pictures and videos are captured.
Corephotonics patented zoom dual camera technology takes a holistic approach in which all the ingredients that constitute an imaging solution are redesigned.
Our zoom technology is based on a unique dual camera design in which one camera sub-assembly includes a lens and sensor that forms a Wide Field of View (FOV) image, similar to that of existing smartphone cameras. The other camera sub-assembly includes a Telephoto lens and an image sensor and form a Tele (Narrow) FOV image.
Typical smartphone lenses include a train of lens elements with Total Track Length (TTL) that is larger than their Effective Focal Length (EFL). In Corephotonics’ patented Tele lens design, the TTL is actually smaller than the EFL. The result is a zoom dual camera hardware that is as slim as standard mobile cameras.
For those cameras that require even slimmer constraints and larger zoom range, we employ a unique folded optics structure with a specially designed Optical Image Stabilization (OIS) actuator. Corephotonics also invented a new type of optical design for folded zoom cameras in which the aperture diameter is very large and is capable of absorbing up to five times more light than standard cameras thereby improving the overall low-light performance.
The Wide & Tele sub-assemblies form a couple of synchronized images, which are then merged together to form a single image in a desired zoom factor using Corephotonics image fusion algorithm, supporting both still and video zooming.