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I shall start by saying this – dual-camera smartphones are all the rage these days. I’ve seen many people looking for a new smartphone, and one of their criteria is “must have dual-camera“. While it is arguably one of the newest feature offered at the hardware level, there are major misconceptions about these dual-camera smartphones.

Lucky for you, we’ve gone deep into this subject and summarized everything that you need to know. Let’s break it all down and have a look with the utmost detail, so we won’t fall into more marketing buzzwords and confusions.

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[alert type=”info” icon-size=”big”]This editorial is not paid by anyone. This is solely to educate everyone regarding dual-camera smartphones.[/alert]


Dual-camera smartphones aren’t exactly a new idea after all. HTC One M8 was announced back in March of 2014, and it’s the first dual-camera smartphone ever. That smartphone was the first one ever that brought this idea to the mainstream consumer market.

Fast forward a few years to 2016, and the re-emergence of dual-camera smartphones started popping up again. It took about a year before it caught on the hype train, and things are starting to get really out of hand right now. I’ve heard people saying that “dual-camera smartphones always means more superior image quality“, and to the point where it is a must when choosing their brand new smartphone. That’s NOT the case! :O

Not all dual-camera smartphones are the same

Dual-Camera Smartphones
They might look the same – but in fact, they’re very different.

There are two different types of dual-camera smartphones. For the lack of a proper name, I just call the first type as “stereoscopic dual-camera system” and the other one as “hybrid lens dual-camera system“. The main difference here is the lens only. The megapixel count can be different between the two cameras on a single smartphone. Let me explain one by one.

Stereoscopic dual-camera system

This kind of system has both the cameras work together to get more visual details, specifically depth information. One camera gets the image, whereas the other camera gets depth information. When both these cameras work together, you’ll get additional features like what we’ve shown here with the with the Huawei P10.

Stereoscopic dual-camera system is like having two eyes – just like us humans

Huawei is the one who made the stereoscopic dual-camera system famous, actually. They’re the ones who employed this camera system since the P9 and it’s conceptually the same as the one used on the HTC One M8. In layman’s terms, this camera system is like having two eyes – just like us humans. Though, one camera can be smaller than the other. Usually the secondary camera is smaller than the primary one.

As a bonus, it tends to have faster focusing speeds and the ability to refocus pictures, too.

Take a look at the Huawei P10’s dual-camera lenses here. One for monochrome and another for RGB, but they’re both identical lenses.

Dual-Camera Smartphones Dual-Camera Smartphones Huawei P10 lenses

For some smartphones, it has two cameras but only one of them can be used to take the picture. The other camera is used for depth data and for faster focusing. Even the original HTC One M8 has dual-cameras that function in this way.

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Phones like the new ASUS ZenFone Max Pro (M1) also has a secondary 5MP that cannot be used to take pictures. That 5MP secondary camera assists the main 13MP camera for data collection only.

ASUS ZenFone Max Pro (M1)
5MP on the left, 13MP on the right

Is using a primary + secondary camera faster than ASUS’s Tri-Tech Autofocus that we’ve seen during the days of ZenFone 3? That is a question for another time.

Hybrid dual-camera system

The other dual-camera system found in smartphones don’t work together, but each of the cameras has their own specialty instead. So how do they work?

Quite simple, actually. Both camera lenses differ from each other – as one lens will have a shorter focal length (wide angle lens) and the other lens will have a longer focal length (oftentimes regarded as “telephoto” lens). You essentially get the best of both worlds when it comes to this type of dual-camera system. One simple tap of a button is all it takes to swap between the two lenses. That means you can frame your shots more flexibility and get a wide angle shot when you’re at a very tight spot.

Hybrid lens dual-camera system setup is like someone wearing a monocle, opening only one eye at a time

The ASUS ZenFone 3 Zoom that we’ve reviewed here has exactly that – instead of having the same lens on both cameras, it has a 25mm lens on one camera and a 59mm lens on another. Like I’ve said before on our ASUS ZenFone 3 Zoom review, its dual-camera system setup is like someone wearing a monocle. So, you can see things through

Take a look at the image here and the lens diameter can actually be seen.

Dual-Camera Smartphones Dual-Camera Smartphones ASUS ZenFone 3 Zoom lenses

Also, this type of dual-camera system is found more commonly on smartphones. Take the iPhone 7 Plus and LG G5 and LG G5/G6 for example. The two cameras that they have are not using the same lens.

There seem to have many smartphones that opt for a wide-angle lens instead. Remember the fish-eye lens craze from a few years ago? The wide-angle lens is the same as other fish-eye lens – just built right into the smartphone itself.

A dual-camera system that can do both?

Yes, there is one particular smartphone that has the features of both dual-camera systems mentioned above. It can have the focusing speed and the ability to refocus pictures like a stereoscopic dual-camera system, while still have the ability to change between the two different prime lenses behind the phone like a hybrid dual-camera system. That smartphone is the Samsung Galaxy Note8 and we reviewed it in-depth here.

This can be done through software magic – and it’s not simple to have both the cameras working in tandem either.

Samsung Galaxy Note8

The cameras on the Galaxy Note8 is special – it has a hybrid dual-camera system. But then again, it can do things that are found on a stereoscopic dual-camera system. Just how? First, the two prime lenses have two different focal lengths.

  • 12MP sensor with 26mm f/1.7 lens; has PDAF, OIS
  • 12MP sensor with 52mm f/2.4 lens; has AF, OIS, 2x optical zoom

The camera sensors will have to do some intense mathematics to match the distance of objects that are in focus for both cameras. It works magnificently as Samsung’s ISP (image signal processor) is strong enough. You’ll have have the best of both worlds!

Samsung Galaxy Note8

Of course, this is still a Samsung-exclusive technology for now. We’ve yet to see any other smartphones with such versatile dual-camera system.

Huawei’s latest P20 Pro has a similar function but it also has triple cameras at the back. Samsung did it with two cameras only.

Finding out what type of dual-camera system is on a particular smartphone

So here’s how we can determine which dual-camera system your particular smartphone is using.

  1. Physically measure the diameter of the lens of both the lenses. If there is a difference, then it’s probably using the hybrid zoom dual-camera system.
  2. See the camera UI if there’s any “switch to secondary camera” button. Try covering one lens and see what shows up on the camera.

The former method is definitely much simpler – but I must highlight one more point. Many spec sheets do not state the focal length, so it’s not such a surefire method after all. The latter is quite difficult to determine without any sort of proper equipment. For me, I took a picture and then did pixel-by-pixel comparison of both the lenses’ diameters.

Let me show you what I mean – that’ll get the message across a lot better than worded descriptions.

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See the difference? Only the Huawei P10 has same diameters. That’s generally how I find out the difference between the two dual-camera systems. Of course, it’s not a surefire way to know what camera system it uses.

Are dual-camera systems better than single-camera systems?

To answer that question, we have three flagship smartphones with three different type of camera systems. The Samsung Galaxy S8+ with a single-camera system, the ASUS ZenFone 3 Zoom with a hybrid dual-camera system, and the Huawei P10 with a stereoscopic dual-camera system.

Dual-Camera Smartphones Samsung Galaxy S8 S8+
The Samsung Galaxy S8 and Galaxy S8+ are highly regarded in mobile photography now.

I’ve taken all 3 flagships with me on a short little lunch trip and took a few shots with them. Let’s see how they all perform – and remember, we’re trying to disprove that dual-camera smartphones are always more superior than a single-camera smartphone in terms of image quality.

Here are 5 sets of images taken by the 3 different flagship smartphones. The first image is taken with the ASUS ZenFone 3 Zoom, then the Huawei P10, and then the Samsung Galaxy S8+. All image sets follow this order. You be the judge of which has a more superior quality, and vote your favourite down below.

Of course, everyone has a personal preference when it comes to which of the images they like the most. So  – which is better?


The one biggest conclusion I can draw out is that having more cameras on a single smartphone doesn’t mean producing more superior quality pictures. Having more cameras does offer more features to play with, but if those features aren’t utilized fully, then it’s actually rather pointless. Might as well save some money for another smartphone that offers better value in other aspects, like battery life.

What do you think of our breakdown and analysis on this hype train?
Tell us down in the comments section below or on our Facebook page – we are interested to know what you think and appreciate your feedback!

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