Why are buttons with smartphone camera so big?

Whether it’s the new Samsung Galaxy S21 Ultra, Apple’s iPhone 12 series or the Huawei Mate 40 Pro, the camera’s housing bumps feel bigger than ever before. In fact, the phones with the largest camera bodies usually take better pictures. Slimming phones, on the other hand, fell into the pick order. Although this trend seems to have a positive effect on the photo quality, it is not the most aesthetic consideration, and it makes for bigger phones.

When it comes to high-end mobile photography, it is impossible to escape the camera bump. But why? To understand this, we need to dive deeper into the inner workings of the smartphone camera.

Take a look at some examples: Mega shootout: the best camera phones tested

Focal length, lenses and crop factors

Before you understand the meat of explaining the camera bump, we need to address some of the key features and terms of all camera designs.

We start with lenses and focal length. Every camera lens, from those in DSLRs to smartphones, focuses the incoming light on the focal point, known as convergence. This focal point is where the image sensor sits to digitally capture your image. Focal length defines the distance from the lens to the focal point, measured in millimeters. In fact, complex low lenses mean that the actual length is often less than the list. However, the effect is the same.

Dive deeper: What is focal point in photography?

Simply put, the focal point defines the camera’s field of view and ‘magnification’. Longer focal length narrows the field of view and increases the magnification. This results in a zoom effect. You can imagine this by considering how changing the focal length changes the viewing angle while refracting the light through a camera lens. See the image below as an example.

What is important is that the focal point also influences the image perspective. There is less visible separation and distinction between foreground and background objects at longer magnifications. Look at the apparent distance between the trees in the image above. Remember this, because we will return to it later. This nuance has been the subject of much debate over OnePlus’ zoom features in the past.

Photography terms explained: ISO, aperture, shutter speed and more

The other equally important part of this equation is the ‘harvest factor’. It is often confused with the characteristics of the focal length. The crop factor of a camera depends on the size of the image sensor. Imagine looking through the camera lens. The lens captures an image regardless of the size of the sensor. Therefore, the final image taken by the lens is cropped depending on the size of the image sensor.

Note that a smaller image sensor has the side effect of producing a tighter crop and a narrower field of view. This creates a more zoomed-in look for full-frame images, known as multiplication of the focal length. This is one of the reasons why you will find small image sensors in smart cameras. However, cutting does not have the same perspective effect as a native focal length focal length with the same magnification. The crop factor is important to understand as it plays a factor in the fields of view for both zoom and wide angle cameras found on smartphones.

The search for larger sensors and longer zoom

With the concepts of focal length, magnification and harvesting factor, we can address the trend towards thicker housings for smartphone cameras.

See also: The best camera phones you can get

The first reason for larger room housings is the pursuit of long-distance zoom. As mentioned earlier, the focal point is an important part of enlarging a camera. Although complex lens structures can enhance effective focal length, a larger distance between the lens and sensor is required for greater zoom. This requirement is the driving force behind the use of periscope technology for many long-range zoom cameras without a large camera bump. It increases the distance from the lens to the image sensor by using mirrors to reflect light. The tendency for longer telephoto zoom features is almost certainly a factor in thicker camera shots.

The second factor that causes larger camera shocks is the desire for larger image sensors. Such sensors improve the recording of light and the image quality. Although the sensor size is more related to the crop factor than the focal length, there are reasons why longer focal lengths with larger sensors may be desirable.

For starters, smartphones probably want to retain the same frame rate and magnification as previous designs when moving to a larger sensor. Keeping the same crop factor with a larger sensor requires a longer focal length. Otherwise you will get a wider field of vision which may not be desirable. This is more important in the context of multi-camera systems, where fixed magnifications are required between the ultra-wide, main and telephoto settings.

Read more: Why the size of the camera sensor is more important than more megapixels

Finally, we need to consider lens distortion, which is usually most noticeable at the edge of the lens. Increasing the sensor size and using a larger lens crop can result in more noticeable distortion. This is probably a problem with small lenses with a wide aperture used in cell phones. See the image below as an example.

Higher quality lenses can help here. However, it is difficult to build for compact form factors for smartphones and their very large opening. An alternative solution is to adjust the focal length. Then the field of view falls through the lens’ quality sweet spot closer to the center, where the chance of distortion is less. However, this again requires the use of a longer focal point and thus a larger camera body.

Also look at the reverse requirements of wide angle sensors. Larger sensors or shorter focal lengths are used to enlarge the crop and / or enlarge the field of view. This is why you will see a lot more distortion on the sides of your wide angle photos.

Why are smartphone camera shots getting so big?

Although there is no single explanation for the increase in camera thickness over the past year, there is a common theme. The trend is down to smartphone camera designers fighting the laws of physics to improve camera capabilities and image quality.

Related: What to expect from smartphone cameras in 2021

The desire for larger range zoom features and larger image sensors to reduce the gap on DSLR cameras are the two biggest factors driving the trend. It is no coincidence that smartphone cameras that offer industry-leading sensor sizes, zoom features and image quality tend to have larger camera shots. While phones that offer more traditional camera capabilities can retain slimmer form factors.

Not to mention the requirements for larger batteries, 5G antennas and several other pieces of technology that all compete for precious space in modern smartphones. There is simply no other option but to build thicker phones or larger camera shots if you want all this technology.