Every year we are going to more, it's been a while since we passed the 20 megapixel mark, but not all terminals handle similar sizes, although it wouldn't be too difficult to do so. My mobile camera is better because it has more megapixels, it's something I hear from time to time, but I'm lazy to stop and explain it every time, so I want to make it clear that a camera with more megapixels doesn't have to take better pictures than another.
This is not only focused on the world of mobile photography, since in the professional field both compact and reflex cameras we could apply the same rule, although among professionals this is already well known.
There are too many variables to look at just one number.
When we take a photo, the size of the image that we are going to capture is not the only point that intervenes at the time of giving us a good photo, also intervene another series of components of our camera or smartphone as the sensor, as well as natural elements, mainly the light. Who has not tried to take a photo in the same place one day with good light, and another with regular lighting (sunset for example) and has found that the difference in quality is immense.
What are megapixels?
The term megapixel has become popular mainly because of the ease with which it is possible to write down the numbers needed to interpret it. The unit of these is the pixel, which refers exactly to a specific point of our image, which is the same as if we look with a magnifying glass our monitor or tele lcd or led (has ever fallen a drop of water on the screen of our mobile and we have seen the dots of colors) and we notice that the images, texts and everything else is made up of small squares. If we look closely to the naked eye on our monitor or a TV of quite a few inches we can see it too.
At the time of generating the image files the same principle is used, the unit of a concrete point (the smallest thing that we can see) would be a pixel, and as the images are seen in two dimensions (2D), these are counted multiplying the width of the image, by its height, to know what we have. I give you an example, if your monitor has a resolution of 1920×1080 pixels the result would be 2.073.600 pixels. Each megapixel (which is the nomenclature of the unit of measurement such as meters, bits, liters, etc.) is composed of 1,000,000 pixels, so we could say that our monitor has 2MP (rounding).
For images the same thing happens but on a large scale, for example a camera or phone that takes pictures of 11 MP will save them with a resolution of 4064×2704, and so on, the larger the image the more megapixels it has, and vice versa. An example of what a pixel would be in a photo enlarged a small area, each point of a given color is a single pixel.
Sensor and image processor come into play
As I mentioned, professionals know that higher numbers don't mean better photos, thanks to a couple of camera components that make it possible to capture images.
In the first place, the sensor that every digital camera includes, we could say that it is the digital "reel", which captures the light that enters through the lens in order to capture what we have in front of us. The more light that enters the sensor (without saturating), the better our photo will be seen, and therefore, if there is no light, there is no photo, we will see everything in black.
This piece is of greater importance, especially for its size, because the larger the sensor, more independent pixels will be able to interpret, this does not mean that physically has to be larger, but usually also has something to do. As we can understand the sensor and the megapixels are linked, but it will also depend on the quality of this how it captures and interprets the light that comes in, better hardware better photo with the same megapixels.
Sensor is usually smaller in phones
In phone cameras the sensor is usually smaller and therefore the captured light is not the same as in SLR cameras, which makes the photos taken with the same amount of MegaPixels are much better.
On the other hand we have the image processor, which will be limited by the CPU and the graphics processor it integrates. This is not a problem, since the cameras have one specifically designed for it, so it does not mean that your phone for being more powerful takes better photos, we are not talking about that type of processor.
We refer to the dependence of image processing, since in cameras it is usually done by hardware (at least in decent ones), while in other devices it is the software (a program) that is in charge of processing it. Also depending on how the software is designed and how well it is able to communicate with the sensors and the camera will be able to store higher quality photos.
The Megapixel Myth
The more megapixels, the better the photos. Error. That is not so and many times we worry about this data when we are not even going to take advantage of it, ie, depending on the utility we are going to give the photos surely we are paying more to not get any improvement in the result.
As we have seen, more megapixels in the sensor does not mean that your photo is sharper, better or with a more vivid color than the one taken by another device with less resolution, and then I leave a test made with two terminals, one is a w100 thl set to 8MP (the top without interpolation), and the other a Galaxy S3 Mini that has 5MP.
As you can see despite having fewer megapixels the photo looks noticeably better when zooming, we can observe the artifacts generated by the camera with more megapixels to try to remedy the lower quality of hardware. What does this mean? Marketing.
I explain, when we're going to change terminal, phone mainly, one of the things you usually see is that it has a good camera, and what do we look at? is not the quality of the sensor, but the quantity of Megapixels. All companies use this to give us one more small reason to choose that smartphone or camera, even though we don't even notice the difference in quality.
The next time you switch phones because the other one has a higher resolution on the camera, make sure you compare the photos you take with the ones you have at the time, you'll probably be surprised.
So how many megapixels do I need?
If you tell me that megapixels is a scam then how many are the right ones for me? WARNING, I'm not saying it's a scam, or that for sure having more Mp will be the same. Keep in mind that they affect other factors, and normally the evolution between terminals also improves the sensor and image processing. What I mean is not to be fooled by high numbers and focus on your needs to not overpay for something you don't take advantage of, or to make sure before changing brands for this reason, because in the same ranges of a brand are improving, for example the iPhone, Galaxy, Experia, and so on.
To give you an idea, if you intend to use the camera only to view photos on your mobile and publish them on social networks, or pass them through Whatsapp, you won't need the same quality and resolution as if you were going to print them. Normally, the publication in social networks or when we send the photos by messaging, they are resized, that is to say, they become smaller so that they take less time to be sent and they are big enough to see them well, whereas in order to print them we need much more resolution.
You have to stop to think about your purpose with the camera you are going to use, and take into account these points, I also recommend to look a little before deciding and see some samples of the photos that is able to make the terminal.
Think that to view on the pc, mobile and social networks do not need more than 5MP, while to print already in standard photo size is recommended a minimum of 10MP. This will also depend on the quality of the sensor and processed, but for that we look for samples on the Internet or known to have that terminal or camera.
Do you have any doubts left? Publish a sample of your phone indicating the model!