Why more megapixels are not mattered in a digital camera?



Today, most cameras produced are digital, and while there are still dedicated digital cameras, many more cameras are now being incorporated into mobile devices, portable touchscreen computers, which can, among many other purposes, use their cameras to initiate live video telephony and directly edit and upload imagery to others. And high-end, high-definition dedicated cameras are still commonly used by professionals.

Digital camera

A digital camera or digicam is a camera that captures photographs in digital memory. Digital and movie cameras share an optical system, typically using a lens with a variable diaphragm to focus light onto an image pickup device. The diaphragm and shutter admit the correct amount of light to the imager, just as with film but the image pickup device is electronic rather than chemical.


Digital cameras can display images on a screen immediately after being recorded, and store and delete images from memory. Many digital cameras can also record moving videos with sound. Some digital cameras can crop and stitch pictures and perform another elementary image editing.


The digital camera began with Eugene F. Lally of the Jet Propulsion Laboratory, who was thinking about how to use a mosaic photo sensor to capture digital images. His 1961 idea was to take pictures of the planets and stars while traveling through space to give information about the astronauts' position.


In 1986, Japanese company Nikon introduced the first digital single-lens reflex (DSLR) camera, the Nikon SVC. In the mid-to-late 1990s, DSLR cameras became common among consumers. And, in 2000, Sharp introduced the world's first digital camera phone, the J-SH04 J-Phone in Japan. By the mid-2000s, higher-end cell phones had an integrated digital camera. By the beginning of the 2010s, almost all smartphones had an integrated digital camera.



Let’s get one thing straight right off the bat: with almost no exceptions, if you are buying a modern consumer digital camera, the number of megapixels it has should be the absolute last thing you consider.

Megapixel

Digital cameras capture images as pixel elements, known as pixels. A camera’s megapixel count simply reflects the number of pixels it can capture by the million. Simply put, a megapixel is equal to one million pixels. For example, a digital camera capable of 3.1 megapixels has a sensor that can capture an image of 2048 pixels wide by 1536 pixels tall, because of 2048 times 1536 = 3,145,728 pixels. A 3.1-megapixel digital camera shoots more pixels than is crisply displayed on a 60-inch, 1080p (1920 x 1080 = 2.1 megapixels) high definition television set showing a Blu-Ray movie. But most people use digital cameras to take 4 x 6-inch prints. Even a 0.3-megapixel digital camera does wonderfully at that.

Does more megapixels matter in a digital camera?

Generally speaking, the more megapixels you have, the more visual noise is introduced into your image. That means that if your camera has more megapixels than its sensor is large enough to comfortably handle, your images will be less clear and crisp, not more so. You’ll be wasting a lot of disk space on images that are larger than you’ll ever do anything with.

Megapixel count is not an accurate reflection of a camera’s quality. It’s best not to stray above 8 or 12 megapixels.

The camera in your cell phone probably has enough megapixels to comfortably blow up to a poster-sized print.


Now, the number of pixels required to print at this highest quality setting is going to vary depending on the size of the print. You can still get acceptable images printed as low as 150dpi which requires a much smaller sensor size. So, if you want really large prints, you need a very high megapixel sensor. Most people don’t print beyond an 8×10 print though so even a small 4MP camera or sensor generally works just fine.


The camera needs to absorb the light through the lens on the sensor. Typically the more light that you have, the better the resulting image that the sensor perceives. The problem is that as you pack in more and more pixels onto a sensor, the less light that the sensor will see for each pixel.

Since the picture is comprised of putting together all these pixels, the less light that an individual pixel receives, the harder the camera has to work to get enough light to generate an accurate color and brightness for that pixel. This becomes an issue, especially when shooting in lower light conditions. This is typically seen as noise in a picture taken with less than ideal light.

In bright light, the 8MP camera is generally going to have more detailed pictures. But what if you are taking a picture indoors at night or outside at night with dim lighting. Suddenly, the image that the 4MP camera takes might end up being clearer because it does not have the noise levels that the 8MP sensor has.


With cameras offering an extremely high number of pixels, the digital zoom can result in closer images that still offer a high level of detail when it comes to printing or using on the web.



So, you don’t need a huge number of megapixels to get some great photographs. This is especially true if the primary use for the camera is to put images on the web or print out in a 4×6 size. If it is going to be a small camera and you want to be able to zoom into an image without having a zoom lens, then more megapixels may be beneficial. Just be sure that the camera will work for the lighting and style of pictures you take. After all, if you are shooting indoors and in low light, lower might be better.


For crop sensor DSLRs, around 20MP is a great ballpark. Canon and Nikon offer cameras with sensors between 18MP and 24MP. That’s obviously more than big enough for almost anything, but the photosites are still large enough that the low light performance tends to be okay.

And full-frame DSLRs have much larger sensors so can handle more megapixels. This has led to a split in the models offered. While there are super high-resolution cameras with 50MP+ sensors; these are best for specialist uses in ideal settings like fashion photography in a studio.





Stock photo from REDPIXEL.PL

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