24 MP from an entry level DSLR

"From what I've seen". Now that is scientfic! Look, I had a 450D for a few years - just let it go in October and it's a great camera. But 12mp is 12mp, except when it's 12mp and then it's just 12mp. If none of these apply, then it's 12mp.

My formula is not wrong. I wish I could sit down with you and say 'see, this it the little corner of 406,272 pixels which you claim makes up the ENTIRE DIFFERENCE between the whole big rectangle and the smaller one inside it.

Really it's not that hard to understand if you don't just throw up your hands and say 'gee this is too hard, and doesn't support what I believe anyhow.'

Again you are introducing un-quantifiable something-or-other.

I explained why your number of 406,272 was rubbish. It's not so much 'my formula' as it is the standard method for calculating the difference between two dissimilar areas. I'm sorry if it's too hard for you to understand. That does not make it wrong by any stretch.

--
Do people really spend $700 on a camera so they can take a picture of a squirrel or a duck?