20 December 2010 at 19:18 #15375
These camera’s give a black and white image and have a microphone. They plug straight into a TV with a SCART socket. Having set up the big spectrum get a pupil to point to the outermost red part of the spectrum, right on its very edge. Then using the camera and TV you can show that there is something past this – an inch or so wide band – IR. Next put the IR transmitting plastic on the ohp. The visible spectrum should disappear and only a band of IR will be visible on the TV screen.
Remote controls will also show up as will IR ports on PDA’s and laptops.
The TV and camera can also be used to magnify meter readings allowing a class to see for themselves.