Photographing with mobile phones with two, three and even four cameras: which lens to choose in each situation

Mobile phones, to overcome the lack of quality of digital zoom, began to add more and more lenses, with their corresponding sensors, to be able to photograph the world from different angles. The problem is that many times we choose one or the other out of inertia. And we can’t forget that choosing a wide or a tele depends on many things. The key is to be clear about what we want to teach.

Photographic lenses show more or less of reality depending on the optical design. The arrangement of the lenses inside define the angle of vision. And it always depends on the diagonal of the sensor. When we refer to a 14mm or a 300mm we always do so according to the diagonal of a full frame sensor.

But there is no such sensor, since it would be impossible for it to house a lens of such dimensions. We’ll have to wait for the evolution of liquid lenses to even imagine it. But surely it is more likely that the software will advance rather than fall into sensors of such dimensions.

Same place, different goal, different outcome

And why do we use one or another focal length? Many will say that it is because with some more information enters and with others less… Some will say that some move away and others approach. It’s an easy way to see it. But we have to get used to saying that they simply show more or less viewing angle. Actually, the goals all they do is cut.

Iso 32 1/500 f1.6 (photo cropped to simulate a tele)

What changes everything is the distance from the lens to the subject we are photographing. Do not believe that the objectives distort or crush the perspective. Goals do not have the power to change reality. We leave that to our creativity and our desire to move.

ISO32 14mm 1/900 f2.4

Here we are going to see that the possibilities offered by current mobiles multiply the final result of our shots by two, three or four. And that it is not the same to shoot with the wide angle as with the tele… And of course not all portraits are taken with the telephoto lens or landscapes always with the wide angle.

The different purposes of mobile phones

It’s a wonder we no longer rely on digital zoom, that aberration that the only thing it achieves is to worsen the quality of our photographs. To get the same result, without losing as much quality, we just need to crop. This is the great advantage and for what it is also useful to have many millions of pixels.

Right now, in mobile phones we can find up to four different cameras, with different objectives: angular, normal and tele. As we have mentioned, they are used, as advertising says, to photograph landscapes or to take portraits. Best of all, we can’t limit ourselves so much. In the end we will use one or the other depending on our needs.

• angular: they offer an angle of vision that goes from 180º (fisheye) to 65º of a 35 mm
• normal: its angle of vision is similar to that offered by one of our eyes
• teles: Significantly shortens the angle of view. It can go from 30º to 2º of a 1200 mm

The differences between one and the other are due to the lenses chosen for their manufacture. For example, for a telephoto lens they make diverging lenses, which have at least one concave face. Body length also plays a role.

The extreme angle distorts the foreground

The best of all is that, on a mobile, they work together on many occasions to achieve a better result. And it is usually useful to get blurs in the mode Portrait, among other things. Or to make a depth map.

If I walk away there is no distortion

And why does my phone say that it has a focal length of 5.1mm, for example? Because it depends on the diagonal of the sensor. On FF sensors the diagonal measures 46mm, hence 50mm is considered a normal lens. From there, the rest of the objectives are calculated according to the sensor they are intended for.

That 5.1mm focal length can be a perfect reference to know the surface of our sensor. And above all to realize that we are dealing with something very small. By the way, on an iPhone 13 it has the same viewing angle as a 26mm.

The keys to choosing the right lens for each scene

To simplify, it has always been said that the wide angle lens is for landscapes or that the tele is for portraits. But it is not true. It all depends on how far we are from the object we want to photograph.

The landscapes are impressive with a tele, and a good portrait can be done without problems with a wide angle. We just have to watch the distance to the subject to take care of the perspective. As Guillermo Luijk says:

A wide angle lens, by providing a greater angle of vision, will make a larger portion of the scene enter the frame, and it will be precisely in the added edges where the distortion caused by perspective will be most noticeable. This apparent deformation is an unavoidable consequence of the physical fact that takes place when we take a photograph: a three-dimensional scene is projected rectilinearly onto a plane (in this case, the sensor plane). Elements that are farthest from the center of the image will appear “stretched”, and straight lines will converge according to a conical perspective.

Just by moving away and changing the lens the result is more natural and looks the same

For this reason, for the rectilinear projection, we have to take into account certain things:

1. If we stand very close to the main object, the foreground will appear noticeably larger than what we see in the background. Then if we want to highlight something that is in the background it may not be a good idea to shoot with a wide angle.
2. For this reason, if we take group photos, we may the people who are at the ends of the image appear more distorted than those in the center. If we want to avoid it, it is best to move away and shoot with the tele.
3. We always think that a portrait is a close-up. And you don’t have to. Sometimes we can learn more about the person if we move away and include the space around him. And always move our model away from the extremes with the most extreme angles of our mobile.
4. We do not need to show all the landscape that we see with our eyes. If we take the picture with the smartphone’s TV, we will have the ability to close the viewing angle of the image and for this reason ‘closer’ the photographed objects. It is the best way to highlight what is further away.
5. If we want to get closer to an object and we can’t because the distance at which we are prevents us from doing so or because our mobile doesn’t have a telephoto lens, all we have to do is crop the image later in any application. This way we will achieve exactly the same angle of vision as any telephoto lens. In return, the image will be smaller.
6. And finally point out an important technical aspect. Not all cameras and respective lenses offer the same quality. We will have to find out what the main sensor of our camera is and use only the lens that it has to achieve the highest possible technical quality.

When you come across a list of tips like the one you just read, try following it as a reference until you master it. And then do not forget that they are only advice, never immovable rules. That’s when you find your true style.

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