Megapixels

Description

The number of megapixels determines how many pixels (picture elements) a digital camera is able to capture in a photograph.  It is a measure of how many dots make up an image and is roughly equivalent to the product of the maximum horizontal Resolution and the maximum vertical Resolution provided by the camera, divided by one million.  For example, if the resolution is 640x480, we multiply 640 by 480 to obtain 307,200 pixels; then, we divide by 1,000,000 to get about 0.3 megapixels.

The more megapixels a camera has, the bigger the prints you can make at a good resolution.  If your camera does not have enough megapixels for the print size you want, the quality of the resulting image will be fuzzy because a lot of the detail will be lost.  Thus, the higher the quality you want, the more megapixels you need. 

Photo quality is achieved at 300 dots per inch (dpi).  Therefore, if your biggest prints will be 5"x7", you need 5x300 x 7x300 pixels or about 3 megapixels.  If good quality, rather than photo quality is what you need, then 200 dpi would be enough; requiring 5x200 x 7x200 pixels or about 1.4 megapixels.  For a 5"x7" print with fair quality (150 dpi), you would need 5x150 x 7x150 pixels, or about 0.8 megapixels.  Of course, picture quality and sharpness also depend on factors such as quality of the lens, sensor, printer configuration, and paper.  Megapixels only measure combined vertical and horizontal resolution.  Also note that different cameras with the same number of megapixels might have different vertical and horizontal resolutions, which lead to different acceptable print sizes.

This feature is tightly related to the Resolution feature.

Providing a value

Select the minimum number of megapixels that is acceptable to you.  If the number you want does not appear in the dropdown list, select "other".  Then, enter the number you want and click on "Recalculate".

Alternatively, you can use the Resolution feature.