jonathan.rawle.org

It’s nearly four years since I bought my digital camera. I chose the Canon Powershot A40, and at the time it was pretty much at the top of the consumer range of digital cameras, with two million pixels. The more “standard” model was the A30, with 1.2 million pixels, so two million seemed a huge number.

Today I had a request from someone who wants to use some of my photos. He asked if I could send high-resolution versions for publication. In my reply, I said I could “only” supply versions that were 1600×1200 pixels. Similarly Emporis, for whom I take photos, now say “4-8 mega-pixels recommended”.

So it seems I’ll eventually need to get a new camera.

I’ve always thought the term “megapixel” sounds quite strange. It’s true that we physicists like our SI prefixes. But in this context “pixel” isn’t a unit of measurement. We are simply counting the number of pixels that the device contains. No-one would say the world’s population is 6.5 gigapeople, or that there are 1.7 kilosteps to the top of the Eiffel Tower! I expect the marketers feel that a camera will sell better if it contains mega pixels.