The Hague, D200 + 16/3.5 fish-eye

[Jakov Minić]

You remove the entire AA filter which is inside the body.
Then you replace it with a dedicated filter of your choice.
The filter that I chose allows visible light to be registered, and that is why I call it semi IR.

Take a look at this:
http://www.lifepixel.com/

[stenrasmussen]

Semi-IR meaning removal of some filter inside? Or half of it?

And you may look here if you're interested:
http://nikongear.net/revival/index.php?topic=1378.0
This is not semi-IR though as the filter filters out visible light.