Dual Camera Quality: Why Do Phones Need Two Rear Cameras?

The LG G5 is the latest release to future dual camera sensors.

Whether you’re an Instagram foodie, a passionate traveller, or simply partial to the odd selfie, your phone has probably become the main device with which you choose to take pictures. And with good reason – smartphone photography is becoming increasingly impressive. Smartphone manufacturers seem to be constantly increasing the number of megapixels in their snappers, and are even showing it off in adverts like Apple’s “Shot on iPhone 6s” campaign.

One of the latest trends is dual cameras. Many of this year’s new releases, such as the LG G5 and Huawei P9, have featured double camera lenses on the back – but what are dual cameras, and why are they better than the more traditional single lenses? We take a look.

What are dual cameras?

Essentially, more and more phones are starting to feature two lenses on the back instead of just one. These two cameras will work in tandem to produce better-quality pictures, more depth field, better zoom, and more performance improving – almost bringing smartphones up to the level of traditional digital cameras, with their larger, more powerful lenses.

Dual cameras are easy to recognise. Take a look at the back of the LG G5, and you’ll clearly see the two lenses next to each other! So when you’re shopping for a new phone and looking for better camera quality, a simple look at the back will let you know what you’re dealing with.

What are their advantages?

The main issue with smartphone cameras is their size: smaller lenses typically produce worse images than bigger sensors do like on DSLR and compact cameras. (Just compare a professional wildlife photograph, taken on a high-end camera with a large lens and powerful zoom to the pictures you take of your dog at the park on your iPhone 5s. They just don’t compare.)

Using two small lenses imitates the effect of a single large one. It gives the phone more opportunity to detect light and gather it, which results in better low-light pictures and a wider field of vision. It’s also good to improve the auto-focus, as well as zooming capacity: some dual camera systems are capable of zooming up to 5x while still keeping the image’s sharpness and quality.

Most dual cameras are capable of taking two photos at the same time, and then combining them into a single picture – bringing the best of both together. For instance, one lens could be taking a wide-angle picture while the other does the zooming. Once these are combined, the resulting picture will have both powerful zoom and HD image quality.

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The Huawei P9's dual cameras were designed by Leica.

Do I need a dual camera?

If you’re an avid smartphone photographer, dual cameras are the way to go! There’s no doubt that manufacturers will be eager to jump on that trend – even the iPhone 7 is expected to feature a dual-lens setup.

Better auto-focus means a quicker reaction time, so if you’re always pulling your phone out to capture a fleeting moment like a bird flying past, you’ll also find that dual cameras help you take much better spontaneous pictures.

However, if you’re more of a casual photographer and aren’t too concerned about the quality of your pictures (for instance, if your iPhone 6 seems to take perfectly good pictures in your eyes) there’s no need to shell out the extra money for a high-end camera setup.

What phones have dual cameras?

Many, many of this year’s new flagship releases feature the latest trend. Phones like the Huawei P9 and P9 Plus, with their two separate sensors (one colour, and one monochrome, which allows them to gather significantly more light and improve low-light performance), are perfect for the night-time photographers among us. Photos inside a dark nightclub or outside on a camping trip will now look 300% brighter!

The LG G5 also comes with dual sensors, which are very noticeable as they protrude from the back of the handset. One of the cameras is a regular, 16-megapixel snapper, while the second one is a fantastic wide-angle lens with 135-degree field of view. It offers you the possibility of taking much larger photos, which is especially useful for group shots and landscapes. This makes the LG G5 the perfect phone to take on a trip abroad.

One of the first smartphones to feature dual cameras was perhaps the HTC One M8. The pair of snappers work in tandem to detect differences between the images they each see, and offer data on the depth of field through the lower-quality secondary sensor. This allows for better separation of the background and foreground, and an almost 3D effect.

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The future of smartphone photography

What can we expect in the next few years? Many upcoming releases are already rumoured to be coming with dual cameras, and we can definitely expect multi-sensors (why stop at two, after all?) cameras to become a permanent, essential part of smartphones.

We’ll need to wait and see – what manufacturer do you think will be the first to feature triple-lens cameras? Tell us what you think on Twitter, Facebook, and Google+!

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