When you use DPReview links to buy products, the site may earn a commission. Image: Canon Canon has announced the RF 7-14mm F2.8-3.5 L Fisheye STM, which it says is the first zoom lens of its kind to ...

Focal length is the optical distance in millimeters between a camera lens and the sensor or film. It determines the height and width of the scene being captured, known as the "field of view." A prime ...