Buyers prioritize three features when choosing their future smartphone: its screen, its battery and its camera. In the age of selfies, the camera increasingly takes first place, at least in the minds of manufacturers. That’s why they keep improving it. But sometimes too much is like not enough…
There’s nothing more like the unveiling of a new phone by a global tech giant than… the launch of a phone by one of its competitors. In a few minutes, we praise the brightness of the screen, the number of pixels found there, the possibility of using the device for hours before having to charge its battery, and then… we spend the next hour detail the sensor and lenses that make up its cameras.
A sign of the times, manufacturers are now including a front camera on some of their phones whose sensor is more efficient than that of the rear camera. Or, they present their folding screen phones as the ideal way to take the best selfies: you can point the phone’s most powerful camera at you and see the framing in real time on the screen.
Pixels that are… mega
For a time, major electronics brands touted the high number of pixels in photos taken by their phones. Each pixel is a point of light intercepted by the digital sensor and recorded in the resulting JPEG file (or RAW, for those familiar with Photoshop).
More high-end cameras have digital sensors that reach 100 megapixels. 100 million points of light which then make up each photo. It’s a lot ! Most of the time, it’s also superfluous. Rarely do we need such a quantity of pixels.
For example, when printing a photograph on photo paper, you only really need about 300 pixels (or “dots”) per inch, the (imperial) measurement used in photography and graphics. If you need to print a photo in 6 x 8 inch (15 x 20 cm) format, the calculation is simple: you will need an image 1800 pixels high by 2400 pixels wide. It will have 4.3 million pixels.
Photos taken with a phone very rarely end up spread out on photo paper. We watch them more often on a screen whose density is less than 300 pixels per inch. We don’t need a 100 megapixel sensor for that.
That said, the more pixels you capture, the more you can improve your photos. Both Apple, Samsung and Google combine data from several pixels to improve the sharpness of the image, or its colors, or another of its characteristics.
A phone equipped with a 48 megapixel sensor could generate photos that end up being only 8, 12 or 24 megapixels.
Zoom zoom
To this day, phones remain incapable of perfectly reproducing the variable focal length telephoto lens. In a word (English): zoom. On automatic cameras, it was this little wheel that you slid with your index finger to frame your subject more closely.
Phones use several lenses placed side by side to compensate. Samsung’s Galaxy S23 Ultra has five. The iPhone 15 Pro Max, which Apple revealed this week, has three, but they are configured to create the illusion that the phone has seven.
One of the lenses of the iPhone 15 Pro Max is quite particular: it produces a “5x zoom” effect, the equivalent of a 120 mm telephoto lens. Like Huawei and Samsung before it, the Californian manufacturer had to curve it, like a periscope (with mirrors and everything), so that it could fit in its phone.
The 120mm focal length of Apple’s lens is designed specifically for portraits. Professional photographers who specialize in weddings like to use this type of lens, with a focal length of 120 to 135mm.
Photographers looking for rare animals will favor a longer focal length, which can go up to 400 or even 600 mm. Samsung does offer image magnification on its S23 Ultra which simulates the effect of a 100x telephoto lens, which is enormous. But the resulting images are most of the time blurry or “pixelated”, where we clearly see the automated retouching carried out by the phone’s algorithms.
But we are not there yet. While waiting for a phone with a real variable focal length telephoto lens, you will have to choose between phones whose camera continues to get bigger