How important is ‘megapixel’ for a camera?

We have given this matter a high priority because most beginners into digital photography are confused about it, and most camera sellers confuse buyers with this.

A pixel is the basic unit of measurement of a picture. These tiny squares when joined in thousands make a big picture. These days, pocket cameras and even mobile-phone cameras come with a high pixel rating, in the range of 3 to about 40 megapixel. What a 5 megapixel photo means that the photo is made up of about 5 million pixels. It will roughly have 2592 x 1944 pixel [width x height]. When the senor of the camera takes a photo, it puts a vaule to each pixel. This value represents the color and other qualities of the small part of photo that it represents. When we see the photo on a computer screen or print it, the pixel shows up these qualities.

A big picture has two main advantages: One. When you want to print a picture with lower size into large sizes, it will not print well. The photo will break into sqaurish patterns rather than being a smooth picture. This simple calculation will show this:

A picture of the size given above [= 2592 x 1944 pixels] when printed at 320 dpi, can give fine prints of about 8” x 6” [because 2592 pixels will approximately fill 8 inch width if 320 pixels are printed in one inch]. But if you print it to a higher size, the quality will sharptly deteriorate.  [This dpi is dots per inch and it shows how fine the printing quality will be. A higher dpi will usually result in better print, other things being equal.]

The second advantage of high pixel numbers is that you can ‘crop’ [=cut and remove unwanted portion from an image] a big photo and the photo will still be good. But if you try to remove some unwanted areas from a small image [=with less pixels], the remaining photo may turn out to be very small.

Beyond what has been said above, pixel numbers are not very important. There are numerous other aspects relating to lens, sensor, lighting, camera settings and the expertise of the photographer that are important for the quality of a photo.