Most point and shoot cameras contain an infrared (IR) filter that enables your camera to reproduce more realistic color. In the iPhone 4 camera, the IR filter was not as good as the one in the new iPhone 4S — users have noticed a significant difference. The iPhone 4S photos, have less of a red tint and appear to be more natural looking.
Why does infrared light show up in photos? The infrared light is invisible to the naked eye and is part of the unseen electromagnetic radiation all around us. However, it can be picked up in a photo when it passes through a camera sensor that does not have an IR filter.
Some professional photographers enjoy working with infrared light to create unique photos. But you really have to understand and know how to manipulate the light. Most iPhone users just want a simple point and shoot camera to capture that special moment as it happens.
The iPhone 4S has proven to have an improved, embedded IR filter, which will reproduce more natural colors, without allowing the infrared light to pass through the sensor. Check out the photos below that were taken by Camera Technica. You can really see the red cast in the iPhone 4 photo.
Here is Camera Technica’s overview of the photos:
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.
We wrote a more comprehensive review of the iPhone 4S, which looked at some comparisons between the iPhone 4 and 4S cameras; you can read it here. Of course, photography is subjective and some may prefer the infrared light. Personally, I think the natural light is more appealing in the pictures I will be taking with my iPhone 4S.
What are your thoughts?