Nikon just filed quite an interesting patent. This patent describes a mechanism that gives a photographer control over the use of Anti Aliasing filter.
If this goes through it could be pretty big. Here is why.
First, What Is Anti Aliasing Filter?
Anti Aliasing filter (or optical low-pass – OLPF) is a thin filter that actually softens the image a bit before it hits the sensor. The reason for this was to reduce moire effects. (Those are a wave-y shapes that you see on images with tight patterns.
This makes sense if you are shooting something that has a repeating frequency like repeating lines, dots or patterns. If the distance between those lines is in certain relations to the sensor, you get this pattern. (think back to news anchors wearing the wrong shirts).
So, Why Remove The Filter?
If you are shooting something with no pattern, you don’t actually get any pattern reducing benefits, while still softening your image.
This makes no sense for some types of photography. Actually, it makes no sense for most types of photography. This is why Nikon had two D800 bodies – a “regular” D800 and a AA filterless D800E body. You could choose sharpness or Moire.
While moire has very small effect on photography, it has a bigger effect on video. When the camera downscales the image from its native format (say down to 1080×1920) thin lines became jagged and pasterns become zig-zaged.
Now You Get Both
This has been a major selling point for the 800 series, but required that you made a choice. If this patent goes live you will not have to choose anymore. you’ll have all the sharpness in the world for shooting stills (AA off) while getting smooth video (AA on), making the DSLR a better dual use device.
The patent, sadly, is in Japanese, so the technical idea behind it can be either Google translated or extracted from the image above but the motivation is pretty clear.