One can calculate the angle, but it is far more

easier to calculate the field of view. (And from there calculate the angle).

All measurements are metric.

Focal length = f (in mm).

Distance = D (in meters)

Sensor Width = w (in mm).

Field of view = D*w/f

Example

D = 100 meters

f = 45 mm

w = 24 mm (Aps size sensor).

Field of view (at 100) meters = 100 meters * 24 mm / 45 mm

Field of view (at 100) meters = 100 * 24 / 45 * meters * mm / mm

Field of view (at 100) meters = 2400 / 45 * meters

Field of view (at 100) meters = 53.33 meters

35 mm film is about 24mm * 36 mm and is diagonal about 43 mm.

aps size sensor (1.5 factor) is about 16mm * 24mm and it's diagonal is about

29 mm

The angle is Atan(FieldOfView/(2*D))*2

Or the angle is Atan(w/(2*f))*2

You can use mm for the focal length and the sensor size and any

other length for the Distance and Field of View. (For example yards or feet,

as

long as Distance and Field of View use the same).

Field of view (at 100) feet = 100 feet * 24 mm / 45 mm

The angle does not behave lineair, Field of view, distance, sensor size etc.

do behave lineair.

*) At very short distances be the field of view should not be used. (think

macro).

Good luck,

Ben Brugman

"Mulperi" <(E-Mail Removed)> schreef in bericht

news:T80Pg.397$(E-Mail Removed)...

> For example the angle of view is 100 degrees in lens x with full frame

> camera and the crop factor is 1.5 in smaller frame camera . So what would

> be the final angle of view with that smaller frame camera with that lens

> x.

>

> --

> Juha Heinonen

> Seilimaki 17 B 8

> 02180 ESPOO

> FINLAND

> E-mail: (E-Mail Removed)

> URL: http://personal.inet.fi/koti/juha.heinonen

>