Assertion: camera's length | /r/HasProperty | focal
Facets:
Source sentences:
text: A camera typically has focal length in a range of 10mm to 500mm.
text: This means a) calibrate the camera to establish the exact focal length/principle distance for more accuracy (or at least use a reasonably close focal length estimate), and b) if using a zoom lens, take photos with the camera set at the same focal length (zoom setting) at which the camera was calibrated (for repeatability, use the widest angle or fully zoomed).
text: To achieve this, the camera will generally set the focal length to a relatively wide angle, the aperture fairly narrow, and the focus to infinity.
text: Having fixed lenses, they are limited to the focal lengths they are manufactured with, except for what is available from attachments.