In April 2016 Huawei launched the P9 in partnership with Leica, with two cameras sitting on the back. Pocket-lint Huawei P9: Leica's monochrome mark That all changed in 2019, as everyone else realised that wide-angle was a creatively sound proposition. LG added the wide-angle to the V20 and subsequent models in the G and V series, but it wasn't until the Huawei Mate 20 triple camera that we saw big moves in wide-angle from other manufacturers. You could simply switch from one camera to the other, perfect for tight spots or landscapes - and the chance to create something you can't do with software.
With 135-degree lens on the rear for that 8-megapixel camera, the LG G5 could shoot wide-angle photos to great effect. Rather than combining information to create effects, the second lens was ultra wide-angle. There was a main 16-megapixel sensor and a second 8-megapixel sensor. Firstly, it attempted to integrate modular accessories - which was a flop - and secondly, LG equipped it with dual cameras, one of the first phones to launch in 2016. There were two things that were interesting about it. Step forward a few years and LG announced the LG G5 in February 2016. HTC might have started this whole second lens thing, but it was about 2 years in advance of the rest of the pack - and it was 2016 that really saw the industry change. There are still plenty of devices that have a second lens for "depth" and nothing else - but that's often seen as a method of getting background blurring on portrait shots.
The effects were rather gimmicky and the benefits of having a dual camera didn't really make an impact - even if the full metal body did. The One M8 was clever, but the camera wasn't that impressive. That meant you could create bokeh/background blur effects, you could refocus the image with a tap and you could easily manipulate photos, keeping the subject sharp and changing the backgrounds, even after you'd taken the photo. The idea was that the second lens could create a depth map and feed it into the final image. With a 4-megapixel UltraPixel main image sensor and a secondary 2-megapixel sensor capturing extra data, the dual lens camera was used, like 3D, to create a sense of depth in photos. The HTC One M8 was launched in April 2014 and used two sensors in the same way that modern smartphone cameras do. It was the HTC One M8 that really introduced dual lens cameras to the world and saw HTC trying to do something different.