More megapixels, good or bad?

In digital cameras film is replaced with a sensor, an electronic component that measures light hitting it. Sensors are split into millions of individual pixels, this is where the number of megapixels comes from. Each pixel measures the amount and colour of the light that hits it to record the image. Early digital cameras had relatively few pixels and suffered from poor quality images because of it. So manufacturers began to produce cameras with more and more pixels, and consumers learned that more pixels gave better quality.

But... digital cameras are complex and the number of pixels is not the only issue to consider. Manufacturers keep on making cameras with higher pixel counts because pixel count is what consumers have learned to look for - and is what will sell. Unfortunately, compact digital cameras have very small sensors (8.8 x 6.6 mm is about the biggest), so to get more pixels into the sensor each pixel must be smaller. Without going into too much detail, smaller pixels are not as good at doing their job, and are more likely to make mistakes. Add to this the fact that aiming light onto a tiny pixel is much harder for the small lens of a compact camera and you find that more pixels begins reducing the quality of photos again.

How many pixels? It is now considered that 6 megapixels (6,000,000 Pixels) is the optimum number considering the size of sensors in most compact digital cameras.

What about Digital SLR cameras? SLR cameras have bigger sensors and better lenses, so they don’t suffer from the same problem. Most could get up to about 30 megapixels before any of the same problems become an issue.