Good Mobile Camera vs. Bad Mobile Camera: 7 Key Differences
As much as the technology behind smartphone cameras keeps improving, not all cameras are made the same. Some cameras offer better performance in low light while others promise higher resolution for picture clarity.
If you’re new to smartphone photography and/or are looking to invest in a phone mainly because of the quality of the camera, it can be a pretty difficult and overwhelming decision to make because of the sheer number of options available.
However, there are several things that you need to look out for that separate a good phone camera from a not so good one. In this article, we’re going to look at seven of them. Hopefully, this will help you make a decision that’s right for you.
And even if you’re not looking to buy a new phone, it’s nice to know what makes a phone camera good.
So, let’s get right to it.
1. Sensor
This is probably, if not definitely, the main contributing factor of picture quality in any digital camera, not just smartphones. It’s also one of the main reason why smartphone cameras lag behind the more traditional cameras in terms of picture quality.
The sensor is basically a device that is made up of light-sensitive photosites (also called pixels) that capture light photons as they enter the camera. The camera’s processor takes this light information from the sensor and uses it to recreate the image of the scene.
That’s a really simplified explanation of how it works. If you’re interested in knowing more, I’ve put together a more detailed (yet simple to understand) explanation of how phone camera sensors work. Be sure to check it out.
Size is really important when it comes to sensors. A big sensor means it can pack a lot of pixels (known as megapixels) or accommodate fewer but bigger pixels. Each of these options has its own advantages, which I’ll touch on later.
Compared to a “normal” camera’s sensor, smartphones have incredibly small sensors. A full-frame DSLR sensor is 35mm in size. The biggest smartphone camera sensor I can recall was just 1-inch, which is about the same size as an entry-level point-and-shoot camera.
To date, no mobile phone camera sensor has reached that size though some have come close.
The size of the sensor on smartphone cameras is expressed in fractions of an inch. Different cameras have different sensor sizes. A good phone camera will have a sensor that is very close to a full inch.
So, if a phone is said to have a 1/3" sensor (such as the iPhone X) and the other has a sensor that is 1/1.7" big (such as the Huawei Mate 30 Pro), the 1/1.7" sensor is the bigger one of the two.
The smaller the sensor, the more compromised the picture quality is likely to be. Things like digital noise start becoming an issue, especially in conditions with poor lighting. Also, the resolution might be lower, which means you’re likely to lose detail in your images.
The average sensor size on today’s flagship phones from the likes of Apple and Samsung is around 1/2.55", although other smartphone brands have bigger sensors. The upcoming Xiaomi Mi Mix Alpha is said to have a 1/1.33" sensor, which will be the biggest smartphone camera sensor on the market upon release in December 2019.
2. Pixel Size
As already mentioned, the pixels (or photosites) are the ones responsible for capturing the light that enters the camera. They can be likened to buckets that catch raindrops in the rain. The bigger the bucket, the more water it will catch.
The same applies to pixels, but instead of rain, they catch the light. The bigger the pixels the more light can be captured by the sensor. This results in well-exposed images, even in situations where the light is poor.
A good phone camera will not only have a sizeable sensor, but it will also have fairly large pixels. This is especially important in camera phone sensors because of how small everything is. If the pixels are too small, the images will be plagued with apparent digital noise.
Let’s go back to the rain and bucket analogy. If we put a big bucket out in the rain and then put a much smaller one right next to it, they will both gather as much water as they can hold albeit the smaller bucket will hold far less water compared to the big one.
What’s inevitable from catching rainwater in a bucket is that you’ll end up with some dirt at the bottom of the bucket. In a big bucket, this is not a big deal. However, in the small bucket, this dirt is very noticeable.
This is a similar problem that a bad phone camera with tiny pixels will suffer from. Because the sensor is a digital device, it generates heat and noise.
If the light-receiving buckets of the sensor (pixels/photosites) are not big enough to receive a lot of light, then the noise from the sensor will be very visible.
The size of the pixels on the sensor is measured in micrometres/microns and expressed using the symbol ‘µm’ or just ‘µ’. One thousand micrometres equals 1 millimetre.
The largest pixel size currently found on smartphone camera sensors at the moment is 1.4µm, commonly found on flagship phones from Apple, Samsung, and Google. Some phones such as the P30 Pro from Huawei have smaller pixels (0.8µm), but they have larger sensors.
If a phone camera has a very tiny sensor and very small pixels, chances are the resulting images will be of poor quality.
3. Megapixels (Resolution)
The surface of the sensor is made up of many pixels. The total number of these pixels is referred to as megapixels. Mega- is a prefix that means ‘of one million’.
So, if a camera is said to be 12MP, that means it has 12 million pixels that capture light to produce an image.
In simple terms, this means that the image is 4000 pixels wide by 3000 pixels high. This is known as the resolution.
The megapixel count of a camera is the source of much confusion, especially amongst the layman consumer and hobbyist photographer.
Because smartphone companies base the marketing of their mobile cameras mostly on the number of megapixels they have, a lot of people believe that more is better.
There is some merit to that but that’s not entirely true. Read the truth here.
The resolution or detail of an image is determined by the number of megapixels of the camera. A picture taken with a 5MP camera will not have as much detail as one taken with a 20MP camera.
So the more megapixels a camera has, the higher the resolution of the images it will produce. This is important if you want to print your mobile photos, especially in very large sizes.
While this is true, packing the sensor with a ton of pixels comes at a sacrifice — the pixel size. As previously mentioned, large pixels are ideal because they’re able to capture more light and perform well under low lighting.
Because smartphone camera sensors are so small, it would make sense to try to fit them with pixels that are big enough to capture as much light as possible but not too few to lose a lot of resolution.
The most amount of megapixels on a phone camera currently is 64MP. That’s found on the Vivo NEX3, Xiaomi Redmi Note 8 Pro and Samsung Galaxy A70s. The size of each pixel is 0.8µm, but they all possess the largest sensor size (1/1.7") on the market.
The Xiaomi Mi Mix Alpha mentioned earlier is said to pack 108MP, each 0.8µm in size, onto its 1/1.33" sensor. That’s an unprecedented amount of megapixels on any smartphone to date.
In my honest opinion, I don’t think cameras need a ton of megapixels. For me, it would have made sense to see these phones with large sensors pack a moderate amount of pixels that are much larger in size.
Unless you want to print large sizes of your smartphone images onto posters and such, there really is no need for anything above 16MP. Even that is generous.
A decent mobile camera will strike a good balance between the number of megapixels it has and the size of each pixel. Again, this also depends on the size of the sensor itself.
4. Aperture
Aperture refers to the diameter of the opening through which light enters the camera. It works pretty much in the same way as the iris in our eyes that expands or contracts to regulate how much light hits the photoreceptors in our eyes.
Similarly, traditional lenses for normal cameras have a mechanical diaphragm that controls how much light enters the camera and hits the sensor. On the barrel of a typical lens, there’s a ring that you can turn to adjust the size of the aperture.
How dark or bright the image will be is determined by the size of this opening which is expressed in f-stops. The smaller the f-stop number, the wider the opening, and ultimately, the more light reaches the sensor.
Aperture can be adjusted on traditional camera lenses but phone camera aperture works differently — it’s fixed. This means that if a smartphone is said to have an f/2.2 aperture, then that is that. You cannot change that to allow more or less light in by adjusting the aperture.
This may sound limiting (and it is) but due to size, smartphone cameras need their aperture to be as wide open as possible in order to allow enough light to reach the tiny sensor.
If you’re looking to buy a phone based on the camera specs, look for one with a really wide aperture. The current leader in aperture size is the Honor 20 Pro, which has an aperture of f/1.4, the widest of any smartphone camera. Other phones are not too far off.
Samsung’s flagship Galaxy S-series phones are known to have an aperture of f/1.5. Starting with the Galaxy S9, they’ve taken things further and introduced something not seen on any other mobile camera. Their cameras have a variable aperture which sees them switch between f/1.5 and f/2.4.
To read the rest of this article, visit https://thesmartphonephotographer.com/good-vs-bad-mobile-camera/
Investing in a smartphone that has a good camera will obviously cost more than one that doesn’t because of the quality of the optics put into it. However, the results that you’ll get from the camera will be well worth the investment.
If you learn how to take great pictures, you could even make some extra money on the side with your mobile photos. You could also print and proudly display them in your home or send as gifts to friends and family. The possibilities are endless.
Originally published at https://thesmartphonephotographer.com on November 3, 2019.
