Duncan, the method is to remove the "Hot Mirror" which is effectively the IR blocking filter from the sensor and replace it with an IR filter.
How it's done can be seen here
http://www.lifepixel.com/ir-tutorial...structions.htm
The major benefit of this method is the increased sensitivity enabling much higher shutter speeds.
The above photo using such as the Hoya filter would have resulted in exposures of around 1/2 sec or longer at f/2.8.
Thanks Andy, all I require now is leaves on the trees, sun, blue skies + some wispy white clouds.
Harry