Coming up on Infrared

I finally started to experiment with infrared photography. I was planning on this since a while and last week I received a Hoya R72 filter. This weekend I did some first tries in New York. So what's the story? Most image sensors in digital cameras are sensitive to wavelengths that our eyes can't see (near infrared).
These are exactly the wavelengths that the R72 lets through and blocks everything else. The funny thing is that even if your image sensor can see this light, it won't get much of it since this is filtered out by another filter inside most cameras before it can touch the sensor. This is done for image quality reasons. As a result you don't have much light reaching the sensor at all once your R72 is attached to your lens. This of course leads to quite long exposure times (minutes). I have to say that this doesn't really bother me. I like long exposures especially when having moving clouds in the frame.
So far I didn't have time for a closer look at my first results. All I can say is that they are really red and that some extra work needs to be done for a decent black & white conversion...