Whatever it is you want to know about cellphone camera sensors, you’ll probably find it in DP Review’s absurdly in-depth article on the subject. It details not only the common misconceptions about megapixels, but also many real world differences. And it contains the diagram shown at the top of this post, showing the size differences between the sensors in various phones, measured in pixels.
The big surprise is that the difference between 4MP and 8MP, and then 8MP and 13MP isn’t that much. There are technically around double the pixels each time, but as they’re all spread around the edges the actual rectangle doesn’t appear to grow much.
The other interesting section illustrates how many pixels you actually need for various purposes. For viewing images on a Retina iPad screen, you’ll need minimum 3MP. To make an A4 print at 300dpi, you’ll need 9MP, which makes the iPhone 5 (8MP) capable of high-quality prints as big as the biggest enlargements we ever got of our holiday snaps.
There’s more: lenses, digital zoom and so on; and it’s all very interesting and well explained. I’d recommend adding it to your Pocket or Instapaper and enjoying at your leisure.
- Source DP Review