When digital camera pixel counts really started jumping up in 2001, I had an Olympus C920Z point and shoot with a 2.1 megapixel sensor.
In 2002 I bought a Sony DSC-F717, with a 5 megapixel sensor and an excellent 5x optical zoom lens for which I paid around $500.
In December of 2005 I looked at the newly released Canon EOS 5D that offered a full-frame (i.e. equivalent to taking a 35mm film image) body that had a 12.8 megapixel sensor. The asking price was around $5K.
I settled on a Canon EOS 20D that was just under $2K (buy it used today for around $700) which had an 8.2 megapixel sensor that was about 2/3 the size of the full-frame sensor.
But, besides the obvious advantage of being able to swap out lenses, I had a hard time wrapping my head around why a camera with just 3 megapixels more than my Sony should cost more than 3 times as much, 3 years later, when prices on point and shoots comparable to my Sony had dropped by 50%.
The knowledgeable clerk made it really simple for me to understand. In fact, it was the inspiration for my tag line “Apprehending Light!”
He explained that not all pixels are equal. Two cameras with the same number of megapixels that had lesser and greater sized sensors would perform differently.
“Why?” I asked.
“Bigger pixels, more light. More light better images.” came the simple reply.
Today I own an EOS 40D with a 10.1 megapixel sensor and save my 20D as a a back-up camera. The 40D is a great camera and a real workhorse. I love it!
Here”s the ESO 40 Sensor measuring 22.2 x14.8 mm.
Nevertheless, now I walk around with a furled brow wondering how to scrape together the $4K for the new EOS 5Ds Mark II with its full-frame sensor at a whopping 21 megapixels!
Here’s its huge 36 x 24 mm CMOS sensor!
Yeah! While the pixel size on the 5Ds Mark II is the same as on the 20D, the 5Ds sensor is more than twice the size of the original 40D. So I”d still have big pixels, but I”d have a whole lot more of them.
Catch more light!