Over the years, smartphone producers have worked hard to give consumers the optimal user experience, and part of this is in the field of photography. Improvements in camera sensors have led to increased resolution sizes for photographs, along with low-light performance gains and optical image stabilization.

However, one element of photography is a problem smartphone producers are working hard to conquer — improving how far a user can optically zoom.

The key problem that smartphone producers have to deal with is that enabling a camera lens to zoom optically requires a combination of lens elements and space. For a camera lens to provide a range of zoom levels, typically referred to as focal lengths, those same lens elements also have to move, and potentially take up even more space.

Your average smartphone is only around a third of an inch in thickness, or specifically for the iPhone 12 Pro range, 7.4mm (0.29 inches). That isn’t a lot of room to play with for a start, but that space has to be shared with other components.

Glass, casing, the display assembly, and any number of other components will take up some of that thickness, leaving just enough for a thin camera sensor to be added. Apple does maximize the amount of space by adding extra thickness in the form of a camera bump, but that doesn’t buy much room for the sensor.

The lens assembly on top of the sensor simply doesn’t have any space to have any moving components, or to use an advanced lens element arrangement to provide far-off zoom levels, so a fixed lens assembly is used. Sometimes movement is possible, such as for focusing or optical image stabilization, but it’s not enough space to improve an optical zoom.

To get around the need to provide a zoom function, smartphone producers use multiple camera sensors on the back, equipped with different lens assemblies to cover telephoto, wide, and ultra-wide images. By switching the sensor being used, and in turn what lenses are being used by that sensor, the smartphone can change the zoom level at that time.

Modern digital zoom techniques do still allow smartphone producers to market their devices as being able to zoom at far higher ranges, which is great for advertising purposes.

For smartphone producers, the question remains: how to add more of that better-quality optical zoom.

Rather than being a pure optical zoom, the camera instead took advantage of its sheer resolution to simply crop the image from the sensor, so that the final image matched the level of zoom the user wanted, instead of scaling or interpolating the image to resize it.

Creating space in this way worked, but not in a consumer-friendly way. What vendors needed was to develop a way to manage space, but without sacrificing the device’s appearance.

Known by the term “periscope lenses” or “folding lenses,” the idea is to increase the amount of space a lens can make within a confined area, by taking advantage of how light reflects. This is somewhat similar to the principles used for a submarine’s periscope, but purely for altering the path of light for a smartphone.

Rather than simply pointing a camera sensor directly out the back of a smartphone, the idea is that the sensor can be placed on its side within the small remaining space of a smartphone’s thickness. While vendors can’t really do much about the overall thickness of a smartphone, it can manage its internal components to give a camera sensor more lateral internal space to use.

Since the system can generate space between the sensor and the reflective element, this means there’s more freedom to use different lens elements than would normally be used in a smartphone’s camera. This, combined with space allowing for a wider array of inter-element distances, means designers can create more optimal lens assemblies and arrangements.

As there’s space to play with between lens elements, it may even be feasible for component producers to include the ability to shift those elements around. This could allow for lenses to provide more control over where the camera focuses and enable even greater magnification levels.

Apple certainly wouldn’t be the first to offer a smartphone with a periscope camera, as a few of its competitors have already shipped models using the technology.

However, Huawei’s implementation of the idea wasn’t perfect. For a start, while it included a 40-megapixel wide-angle camera sensor and a 20-megapixel ultra-wide-angle version, the sensor used in the folding camera was just 8 megapixels in resolution.

This time, the system enabled a 4x optical zoom, a 10x “lossless hybrid optic” zoom that used techniques such as sensor cropping and pixel binning, and more typical digital zoom techniques for its 100x zoom function.

The two releases showed the potential of using a periscope-style lens system, with a far improved optical zoom than normally possible in a smartphone without sacrificing the device’s physical styling.

By December 2020, reports pointed to existing Apple camera partner LG InnoTek potentially tapping Samsung for actuators and lenses for the creation of folding camera modules. Those modules would then be destined for use in future iPhone models.

An Apple patent application image for a periscope lens that has moving elements for OIS and autofocus.

Naturally, Apple has filed multiple patent applications in the field. One that surfaced in January 2021 suggested the use of an actuator to move lens elements within a folded camera system, one that could potentially provide optical image stabilization and autofocus capabilities.

Of course, the research and development may not necessarily end up in an iPhone, though it seems a quite obvious application for the system. It’s plausible for the technology to be used in other ways.

All signs certainly point to Apple employing periscope lenses in some fashion in the future. It only remains to be seen when Apple will pull the trigger and include the component, and how far it can push the technology.

I know it would be better to have the zoom lens assembly inside the iPhone but I’d also like to see Apple work on a model with an integrated external lens mount complete with all electronic connections necessary to have a fully functional zoom, real macro and closeup lens along with an anamorphic lens. Yes, I could buy Sandmarc, et.al., lenses but I’d rather have as integrated a lens assembly as possible without having sixteen lens on the back of my camera or having to carry a medium size bag with larger lenses. If Apple can design an internal zoom lens they can design a small, yet very capable, external lens that screws on. Once Apple includes a full featured camera mount the third party market would explode. 

These articles that discuss improving zoom on iPhones / smartphones give the wrong impression of what these camera lenses can do. None of the three current lenses offer ANY zoom.

No, the Pro Max does not have a RANGE OF ZOOM of 2.5 x in and 2 out. There is no range. There are three optically fixed options (0.5x ultra wide, wide, and 2.5x telephoto lenses, with no optical settings in between
these options.

I wish these tech review sites would assign people who actually know about the technology field they’re writing about.

This content was originally published here.