So why, Father Pitt asked, is it advertised as a 12.1-megapixel camera? He could not come up with any good answer to that question. Every definition of “megapixel” he found said that it was a million pixels, not a scant million, not a baker’s million, but a plain old honest-to-goodness million. Multiplying 4,000 by 3,000 gives us 12,000,000, according to the old-fashioned math Father Pitt learned.
Yet cameras with a resolution of 4,000 by 3,000 are usually advertised as 12.1-megapixel cameras. It seems to be the industry standard.
So Father Pitt came to us and asked his question, and of course we gave him the verbal equivalent of a shrug and asked why he thought we should know.
But then the question ate at us.
Well, here is a job for artificial intelligence! Surely the bots, having absorbed the wisdom of the entire Internet, would have come across exactly the answer we were looking for and could distill it into a few short paragraphs in the style of a junior-high-school essay.
So we asked Google’s pet bot, “Why is a resolution of 3000 by 4000 called 12.1 megapixels instead of 12.0 megapixels?”
The answer came quickly and included a numbered list. It began, “A 3000×4000 resolution is exactly 12,000,000 pixels (3000 x 4000), which rounds to 12 megapixels (MP), but…”
Hold on there, Googlebot! You say 12,000,000 pixels rounds to 12 megapixels, but by Dr. Boli’s calculation it is exactly 12 megapixels. This is the anomaly for which we sought an explanation. You are indulging in a petitio principii, or in plain English begging the question.
At any rate, the bot tells us some things that are of little use, the only possibly relevant observation being that sensors don’t necessarily have exactly the stated number of pixels, so there might be slightly more than 12,000,000 pixels in the sensor—which may be true, but not in any way useful if the images that come out are exactly 12,000,000 pixels.
“In summary,” the bot concludes, “your 3000×4000 image is exactly 12MP, but cameras often have sensors with slightly different dimensions or use marketing-friendly rounded numbers, so 12.1MP is just a slightly more detailed label for what’s essentially a 12-megapixel sensor/image.”
It sounds as though the bot has come up with a very polite way of saying, “Your image is exactly 12 megapixels, but marketers lie.”
However, it occurred to Dr. Boli that there are many professionals of different sorts among his readers, and perhaps some of them might know why a camera that produces images with 12,000,000 pixels is sold as a 12.1-megapixel camera. Is there any good answer? Or do we have to settle for “marketers lie” and sadly shake our heads at the state of the world we live in?