A method and apparatus for performing surveillance comprising: imaging, at a first frame rate, an area (4) to produce images; detecting, using the images, a feature of interest (22) within the area (4); determining a region of interest (24), the region of interest (24) corresponding to a region within the area (4) in which the feature of interest (22) will be located at a later time-step; and, at the later time-step, using the region of interest (24), imaging the area (4) such that images of the region within the area (4) in which the feature of interest (22) is located are produced at a second frame rate, while images of the rest of the area (4) are produced at a third frame rate, the second rate being different to the third rate.