A lot of nerds had a small problem over how he did this; he didn't take those pictures with 3 different cameras, he digitally dropped the resolution to be equivalent in post.

Another thing thats worth mentioning is that if you use your 5 or 7 megapixel camera and don't shoot uncompressed .tiff or barely compressed .jpeg, you're pictures aren't going to be as clean. Seems obvious, but due to space constraints on hard drives and camera cards people generally shoot significantly below the rated megapixel size their camera can shoot.

Pogue is a twit.

isnt the reason people use / need higher res cameras is because they intend to print the image at a scale bigger than A4 ? like, 3 MP for a billboard would look crappy.

my understanding, anyhow.

Yeah or if you want to crop the image but still have enough pixels for a clear print.

Clever way to dramatize an abstract idea.

The main reason to avoid buying more pixels than you need is sensitivity. The smaller an imaging cell is, the less light it gathers. For concert photography that I plan to put on a web page? Give me a 2 megapixel camera with great sensitivity. Also, the smaller the cell, the more noise.

Ok, in defense of the method used in video, resampling image:

David Pogue is showing the effect of only one variable on image quality. There are so many things which effect image quality from camera to camera. If you want to test only one variable then you must ensure that the others stay exactly the same. His method of testing ensures that only the resolution changes and nothing else.

If he were to have used three different cameras then there would have been all sorts of other things changing (image processor for CCD, sharpness of lenses etc.) which would effect the image and skew the results of the test.

You will get a better picture from a camera with great optics and a low megapixel than vice-versa. Also, when enlarging, which is where everyone says the megapixel count is important, the image sharpness is much more critical.

I'm a large format printer by trade and anything over A2 size only needs to be printed at 72 dpi max, and can easily go to 50 dpi as long as the image is sharp. If the lense is soft or the image processor poor then no amount of resolution can save your shots. We've had a lot of dissapointed/surprised customers wanting enlargements from their cheap 10 megapixel camera who moan it's all fuzzy when blown up.

I show them my camera (8 megapixel SLR) and they can't believe how stupid I was buying it: "Mine cost a third of that and it's got 10 megapixels!" They look at me in a pittiful way , how silly of him to waste that money. Then I show them prints of mine and they see why I spent the money on lenses not megapixels.

Megapixels are great if you can afford them with optics but I only have so much money and when buying a camera OPTICS COME FIRST!

'Yeah or if you want to crop the image but still have enough pixels for a clear print.'
exactly. you'll want to crop it or even zoom in on a part of the pic, this is what megapixels will do for you