The Samsung Galaxy Note 8 feature rear dual camera setup. One of the main advantages of this setup is that each camera has a different focal length. The first camera is a 12MP camera with a 1/2.55" sensor/ a f/1.7 aperture and 26mm equivalent focal length (A wide angle lens with 77-degree field of view). The second camera is a 12MP as well, but features a 1/3.4" sensor (smaller than the first), a f/2.4 aperture lens (slower than the first) and a 52mm equivalent focal length (45-degree field of view). Furthermore, both cameras have an Optical Image Stabilization (OIS) and a dual pixel phase-detection autofocus system.
As you can see from the specifications above, the second telephoto lens provides twice the focal length of the first one (26x2=56) thus the 2x optical zoom. It's important to note that you can zoom-in through the zoom range, you either take a photo using the first camera or the second camera, it doesn't work like in a single-lens zoom lens in conventional digital cameras. Furthermore, don't confuse an optical zoom with digital one. This is lossless optical zoom, there isn't any negative implications on the image quality.
The wide-angle lens is good for general photography and also great for taking pictures of landscapes, buildings or indoors. The telephoto lens provides higher magnification and it's better for taking portrait pictures. It's also great for taking pictures of subjects that are further away from the camera, especially where you don't have any option to get any closer to the photographed subjects, like when taking a picture of a lion in the zoom. You can also take better zoomed-in pictures of things that are way above you, like taking picture of the clock of the Big Ben in London. Of course 52mm isn't a very high magnification, so it's not like you have a 200mm lens to shoot with, but it's certainly better than shooting just with a single prime lens, like most phone have.
Now, let's talk about the good and bad of each lens so we can learn about the pros and cons of this dual-camera setup of the Note8. Of course I put the dual-camera setup as an advantage because of the benefits that this setup brings with it.
The wide-angle lens is actually the best camera among the two for taking low-light pictures. The reasons for that is that it features a large sensor (1/2.55-type) and if I am not mistaken, this is the same sensor as the Galaxy S8 and Galaxy S8+ they both have the same specifications and I've read on several websites that it's indeed the case. Because both cameras have the same resolution and the wide-angle camera has a larger sensor, the pixel size of the wide-angle sensor are larger, measuring 1.4µm same as the S8. The telephoto lens features a smaller 1/3.6" sensor, thus the pixels are smaller, measuring only 1.0µm.
The second telephoto camera also comes with a slower f/2.4 aperture lens, compared to the f/1.7 one of the wide-angle camera. We can expect the same great low-light performance of the Galaxy S8 in the Note8 as well, because these are basically the same wide-angle cameras. The thing that changed here is the you now get a second camera in the phone. The downside of the telephoto camera is that like the iPhone 7 Plus and the Oppo R11, the telephoto lens is slower than the wide-angle one. The iPhone 7 Plus has a f/1.8 aperture for the wide-angle lens and f/2.8 for the telephoto. The Oppo R11 has f/1.7 aperture for the wide-angle lens and f/2.6 for the second lens.
The difference between F1.7 and F2.4 is 1-stop. In other words, the wide-angle lens allows two times more light to pass through the lens compared to the telephoto one. This is a big difference that has high implications on the low-light performance of each lens. Of course, as in this setup, the wide-angle lens considering all that we've mentioned above, is much better for low-light photography.
Before I move on, here is a good video by Techradar that showcase the 2x optical zoom in the Note 8 camera app.
There are good news though. Both cameras, like in the iPhone 7 Plus, have an optical image stabilization. In Samsung's official website, Samsung calls it Dual OIS, which means that both cameras have an OIS system. The OIS system helps to improve the low-light performance, because it allows the photographer to shoot at slower shutter speed (I assume around 2 to 3 stops less) while still be able to obtain a sharp image. There are dual cameras where there is not OIS for the second sensor, but many of those are mono+color combo cameras, where the monochrome sensor is actually used to obtain more light and help improve the image quality, and it's not a telephoto lens.
One of the main benefits of having dual-camera setup like the Note 8 has is that you get to enjoy a more versatile camera. Each camera has a different field of view that is suitable for different type of scenes and subjects. You can be more creative and come home with more interesting and unique photos. Portrait photos shot with the telephoto lens will look better with natural shallower depth of field, more compressed background and better framing.
If you want to use the same setup on a DSLR camera with those fast aperture lenses, you had probably needed to carry two separate lenses in your camera bag and change lenses based on the subject being photographed.
. LG went the other way around, offering users with an even wider angle camera. One of the main benefits of this setup is that it allow users to capture really unique wide-angle shot and it's better for landscape and when shooting in tight indoor places. The Samsung Galaxy Note 8 has a second telephoto lens, not an ultra wide-angle lens. That lens is magnifying the scene for better close-up shots, whether the LG G6 second lens capture a wider area of the surrounding. You choose what you prefer best; I personally prefer an ultra wide-angle lens because of the unique perspective it gives me when shooting outdoors.125-degree field of view, with a ultra wide-angle lens one, just if you wondered. The LG G6 has two cameras, one with a 75-degree field of view (the Note 8 has 77-degree for the wide angle camera) and a second lens which has an LG G6I also want to note that this dual camera setup is different than the
Overall, it's certainly a big advantage having two cameras instead of one, especially when the first one is the same great camera as the Galaxy S8/S8+ and now you get a second camera with 2x optical zoom. A great camera for those who love taking lots of photos and need more versatility to be more creative with their mobile phone cameras.