Are two cameras better than one?

By Adrian Toon, director of a2n.

So why do most smartphones now have two or more cameras?

Normally, if you have an DSLR you will change a lens if you want to achieve a wide angle shot or put a zoom or longer focal length lens on your camera for that distance shot.

Because of the tiny cameras in smartphones, changing lenses is not possible, but because the optics and sensor are essentially built on a chip, a longer distance camera can be added to the phone, which is easier. No phone at the moment has achieved an ‘in smartphone’ complex optical zoom lens arrangement.

Using two different lenses will move away from the single lens ‘digital zoom’ where just the centre of the image was enlarged without capturing more data, now the long-distance lens captures the additional data. Interestingly, the zoom feature on your phone is still a digital zoom, but takes its data from both cameras together, more from the long distance lens at the extent of the zoom.

So, the answer is yes, as far as smart phones are concerned, the more images you can gain data from, the more data will be in the final image. It is worth remembering that because the software to achieve twin camera work is quite complex and extensive it can capture such things as accurate distance (there is an app for that) and enhanced bokeh as described in our last column.

So why is it important in portrait or press photography? The ideal focal length, using the 35mm camera terminology, is around 70 mm, which is a zoom setting between the lenses used on most smartphones. This setting offers probably the most natural images of faces and groups of people for promotional purposes.