Sometimes called hot mirrors, these are filters designed to stop infrared light from reaching the sensor. These are incorporated into many cameras as standard, although the term also refers to filters which can be mounted on lenses.
On sale: 14th Feb
We introduce the new and improved look of What Digital Camera with 102 camera reviews, while in a high-resolution battle, the Sony A7R and Nikon D800E go head to head, plus we've put together an essential guide to Wi-fi.
Which of the new cameras announced so far this year are you most excited about?
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