Not bad at all Snockerty, how long was the exposure?
I'd expect it to be fairly long as DSLRs pass very little IR on account of the IR-blocker filter. I reckon that garden shot was done with a modified camera.
Originally Posted by The Snockerty Friddle
if I add a filter to keep out all but IR light, how do I get any image at all?
I think it's because the IR blocker isn't 100% efficient. I'll see if I can lay my hands on a transmission graph.
If you were serious about this lark, you could get a cheap obsolete model off fleabay (eg Canon EOS10D) and get the filter ripped out.
PS, this was shot with a 742nm IR-pass filter and Imaging Source webcam, if that counts.