Field Of View And Image Circle - Canon 10 x 30 IS Manual

Field of view and image circle

Film for 35-mm cameras has a set standard format
(24 x 36 mm), and if the focal distance is the same, generally
the angle of the lens will not change. However, the field of view
is larger than the film, and the part of the view which is larger
than the film is called the image circle (Fig. 6). The field of
view for binoculars is usually everything inside the perimeter
of the image circle.
Lens
Field of View/Real Field of View/Apparent
Field of View/Field of View at 1.000 meters
Wide field of view
Narrow field of view
(Fig. 6)
Image circle
Film format