Hi Steve, I have used a 720 nm IR filter with some success. In full sunlight this requires exposures in the 3-4 second range. This filter still let's some near IR colours through and you have to do the channel swapping in post. There is an example picture in my gallery of the results. I have also tried a 850nm IR filter which blocks more of the red spectrum but exposures using this filter were into the 2 minute range, but this was on a cloudy day. Still waiting for a sunny day to try it properly but it is constant rain and flooding in Cornwall at the moment. Hope this info helps.