By Biraj Subedi
A megapixel is essentially one million pixels. Pixels are the tiny dots that make up a whole picture, and are what you can see if you zoom too much into an image, or if you press your nose up against your computer screen. The megapixel number defines the picture resolution only from printing perspective. The more the megapixel value you have, the bigger the print you get. If you’re reading this on an HD screen, you’re seeing about 2 megapixels. If you’re reading this on a top-of-the-line 4k screen, you’re seeing a little more than 8 megapixels. It only takes about 7 megapixels to print a nice big photo for your mantle. With 10 megapixels a photo across the top of a page in “National Geographic” can be printed.
Most smartphones released in the past year or so will feature at least a 5 MP camera, though the more modern handsets have 13-18 MP cameras built into them. Typically, one would assume that the more megapixels a camera has, the better photographs can be produced. Most phone manufacturers will have you believe that the higher the megapixels in a camera, the better quality the photographs can be produced.
The quality and sharpness of a photograph when taken on a mobile phone or camera often has less to do with the camera’s megapixel count, and more to do with the photographer, subject, lens, flash and sensors. For example, if you are trying to capture the registration plate of a moving vehicle, doing so on an 8 MP camera probably won’t give you any better results than doing the same thing on a 5 MP camera. The problem here lies in the fact that any camera tends to have issues with capturing objects that are moving at a great speed, or by people who don’t keep their hold completely still.
Factors affecting image quality:
- Sensor size
The size of your camera sensor is one of the most important factor affecting your picture quality. The bigger the size of the sensor, the better the picture quality. That’s the main reason why compact cameras with higher megapixels have low picture quality than a normal DSLR, simply because all DSLRs come with larger sensors than the compact digital cameras.
- Pixel density
Pixel density is simply a measure of how many pixels will fit into a given area. It is determined by the size of the pixels: the smaller the pixels, the higher the pixel density. Increasing the pixel density of a sensor increases its resolution (more megapixels), which can be a good thing, but also usually increases its susceptibility to light noise, which can be a bad thing. Hence more pixel density, i.e. more Megapixel does not necessarily result in good image quality.
- Lens quality
Better lens quality means better glass will give better image quality. Elements such as better Bokeh (the quality of background blurring), less distortion and flare, and larger constant aperture for better results in lower light are the elements that determine image quality.