Quote:
Originally Posted by Taallyn
The megapixel rating basically correlates to how big you can print. It doesn't really have anything to do with image quality per se.
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Actually, that's not quite true.
There is a relation between the density of pixels on the sensor and how well the sensor handles noise. The higher the density e.g. cramming more pixels into the same space, the relatively more noise the camera will produce.
For example, take two camera sensors of the same physical size, and one is 6MP and the other 10MP. Everything else being equal, the 6MP should produce better quality images - especially at higher ISO - when compared to the 10MP sensor.
This is why DSLRs with a low MP count e.g. a 6MP (say a Canon 10D) can produce better quality images than say 12MP stuffed into a smaller P&S sensor, especially when you start shooting 200-400ISO or higher.
Just as there is an exposure relationship between aperture, shutter speed and ISO, there is an image quality relationship between megapixels, sensor size and ISO.
This is the reason that full frame DSLRs (Canon 5D, Nikon D3) have far better high ISO performance than most other cameras - they don't cram as many pixels into the same amount of space that a crop sensor or a P&S sensor has. The higher the density of pixels on the sensor, the more noise as ISO increases.
So, when purchasing a camera and considering image quality, the megapixels mean nothing without thinking about the physical size of the sensor, and what ISO speeds you're going to be shooting at.
For the original poster, if you want better quality, you want to balance the physical size of the sensor against the number of megapixels.
Some more info is available here
http://en.wikipedia.org/wiki/Image_s...f_sensor_sizes
Cheers Gav