I have long been fascinated with infrared (IR) photography and have made the occasional attempt at it in the past using a Cokin IR filter on my DSLR, with variable results depending on which model I was using at the time. In this post I'll be talking about some basic principles up to some issues to consider when buying kit. Digital photography sensors are inherently able to detect wavelengths from ultraviolet (UV) way into IR, having a sensitivity range from about 250nm through to well over 1000nm. The thing is, for conventional photography that's a pain in the back side because it causes all sorts of colour casts from the sensor picking up bits of light that our eyes can't. In order to get round this, manufacturers place a blocking filter (often referred to as a 'hot mirror' filter although heaven knows why) which cuts out the UV and IR light, leaving just the visible spectrum of around 300-700nm and joy of joys, your pics look normal. Luckily for people who