The Megapixel Myth
The megapixel rat race has followed the same pattern as the Processor Speed in GHz in the Intel and AMD war. Unfortunately more important specifications get buried in the Camera Manufacturers’ over empasis on the Megapixel.
A higher Megapixel camera will result in better quality image IF the picture is printed on a larger size paper. Put it in a simpler way – let us assume you have a 12 Megapixel camera – shoot it at two different megapixel resolution under the same condition one at highest resolution and one at lower resolution, say 6 Megapixel. Now take a 4″ x 6″ print of bot the pictures. Do this exercise for a few photographs. Now take the prints to some of the friends and ask them to classify which one is better. Chances are, the result will be dependent more on the fact whether you shook your hands while taking pictures rather than on Megapixel.
Now enlarge the picture size to say, 15″ or may be 30″ ( if you can). Chances are, you DO notice quality difference in 30″ size as pixelization effect starts taking dominance.
Higher megapixel has one more disadvantage – it takes up a lot of space. And while memory cards are coming bigger and cheaper, the transfer speed of the USB cable has not improved ( let us assume USB 3.0 has not become common yet). The bigger images take longer to transfer. Most of the time you are likely to use the pictures for facebook, email etc., and you are likely to reduce the image in size ( resizing ), before sending. This leads to wastage of time.
One quick solution is to take all snaps in lower Megapixel resolution, unless you are pretty sure you are going to take large portrait print of the picture.
Instead of the Megapixel, focus on another important parameter – the Image Sensor size. If the image sensor is larger in size, more light enters the camera which leads to marked improvement in the quality of the picture, especially in low light situations. A camera with larger sensor size and lower Megapixel resolution is better than a Camera with lower sensor size and higher Megapixel resolution.
If you have a very high Megapixel camera in a very small sensor, you are essentially filling the sensor with a lot of noise. This results in poorer image quality.
Common Image sensor sizes are as follows ( Smaller to higher)
1/3.2″ ( 4.54 mm x 3.42 mm or 15.5 sq mm_)
1/2.5″ ( 2.76 mm x 4.29 mm or 25 sq mm )
1/1.8″ ( 7.18 mm x 5.32 mm or 38 sq mm)
Super 16mm (12.52 mm x 7.41 mm or 92.8 sq mm)
Common Digital SLR cameras have a sensor size in the vicinity of 350 square mm.The medium-format digital cameras have sensor size of 48 × 36 mm. So a Digital SLR Camera is able to get you a better quality even at lower resolution.
Optical Zoom is another important parameter that you may like to consider when buying a digital camera.