Jer wrote:
John, it doesn't work that way. One is a lens resolution the other is sensor resolution. You can then upscale your comparison to a full frame sensor. Sensor size is critical when you are making enlargements. Otherwise, a 1/16 inch sensor with a high pixel count would make enlargements of 40X60 inches.
To buy a high pixel camera just to crop has other problems like photo detail, low light, fbs, lens quality, etc.
I realise that, and I was trying to keep it simple. Fact is though, you'd need around 14mp to match the best the OM2 lens I had could offer and it was probably similar for other SLR lenses around at that time. The size of the sensor and the space occupied by each individual pixel are points to be considered and I'd like to aim toward a 5D mk3 full frame 22mp job. The pixels on this have got room to breathe and will need less manipulation later to recover any abnormalities in the image. I've a lot to learn in this respect but think I've got it right thus far.
My Nikon AW100 (16mp on a point and shoot) illustrates this perfectly. Blow up (100%) any image taken with it in anything less than bright sunlight and the amount of in-camera processing is clearly visible.