The Difference the iPhone 4S IR Camera Filter Makes

At Camera Technica, there is a great post about how infrared affects image quality, and why Apple’s IR filter leads to so much higher quality photographs.

When IR light is allowed to pass through to the sensor, the IR light contaminates the channels (mostly the red channel) with information that was not visible in the original scene. The result is an image with a color cast. The images below show the impact of IR contamination on a scene with a dark background. The iPhone 4 image shows a reddish cast due to the extra IR light recorded on the red channel. The 4S image shows a background which much more closely resembles the original scene.

I thought it was cool to see the improvement:

Read more at Cult of Mac