A camera has a square format of 19cm. and focal length of 90mm. Determine the angular field of view.
\[
\alpha = 2\arctan\frac{d}{2f}
\]
\[
d = a\sqrt2
\]
\[
d = 19cm.\sqrt2
\]
\[
d = 26.87005768509cm. \times \frac{10mm.}{1cm.}
\]
\[
d = 268.70057685089mm.
\]
\[
\alpha = 2\arctan\frac{268.70057685089mm.}{2(90mm.)}
\]
\[
\alpha = 112^{\circ}21’52.13″ \leftarrow \text{answer}
\]