Brush up on your Digital Camera language folks. The Digital sensor in the EVO is a newer generation of sensor than whats in the Iphone 3GS, and it's manufactured by the same company, same technology, same production processes..... the words cheap is a poor way to describe the sensor.
More Mega Pixel does not equal better quality. Generically, you getter better quality from larger pixels (pixel pitch) and larger camera sensors. In reality there are many specs to the camera sensor that really dictate the "quality". I'll try to keep it as simple as possible.
The Iphone 3GS has a 1/4 camera sensor, the Evo a 1/3.2 camera sensor (slightly larger). The Iphone's sensor is divided into 3.1M pixels providing a 1.75 pixel pitch (Large), the Evo's sensor is divided into 8M providing a 1.4 pixel pitch (small). What this means is that although the Evo has a larger sensor and more pixels, those pixels are less "sensitive" because they have less area to capture light. This correlates directly to why low light conditions would lag in the Evo. The Iphone has larger pixels, better capable at capturing more light per pixel. In good lighting the Evo should have superior pics. Since this same sensor is responsible for video, the same applies to video capture for each phone.
Now that was speaking from a purely hardware specs comparison of each sensor. The design of the sensors give the manufacturers of the phone a great deal of freedom over the operations of the sensors (metering, etc etc etc).... so the other part of that equations is going to be the software written to control the camera sensors.
If I were to describe the sensor in the Evo, I would call it a marketing trick that plays into the consumers line of logic that more MP = better pictures. The engineering behind it produces 8MP, but it hampers sensitivity of the sensor, which can introduce the blurring you guys see. This is very reminiscent of the Intel vs AMD clock speed wars, where AMD proved with the Athlon line of processors that you can compute more data with lower clock speeds.
Just to set up some of the fragile egos for the Iphone 4 release..... it will have the same size sensor as the Evo, with 5MP, giving it 1.75 pixel pitch..... theoretically producing better pics! It will also be better at taking wide angle photos due to the packaging and the lense.
