01-15-2011, 08:05 PM

[quote name='genotypewriter' timestamp='1295119308' post='5545']

6000/(104.3/73.7) ~= 4240 pixels wide

[/quote]

I'll show you the error

[quote name='blende8' timestamp='1295119677' post='5546']

I don't know what you are calculating, Rainer.

Focal length is proportional to HFoV.

If you double the FL you get twice a much on your image.

[/quote]

No ... VoF (regardless of horizontal, diagonal or vertical) is only

approximatly linear ... and only if you stay quite near to the startingvalue ...

For everythig more global, FoV of a rectilinear lens follows the function:

FOV (rectilinear) = 2 * arctan (frame size/(focal length * 2))

with the arctan-function as a nonlinear element in it ... for small differences

of the term within the arctan-function, you can approximate this by a linear function ...

but going from 14 mm to 24mm is nearly a factor of 2 ... that is a very long way from

being a small change.

For a better and in depth explanation .. see here:

http://en.wikipedia.org/wiki/Angle_of_view

6000/(104.3/73.7) ~= 4240 pixels wide

[/quote]

I'll show you the error

[quote name='blende8' timestamp='1295119677' post='5546']

I don't know what you are calculating, Rainer.

Focal length is proportional to HFoV.

If you double the FL you get twice a much on your image.

[/quote]

No ... VoF (regardless of horizontal, diagonal or vertical) is only

approximatly linear ... and only if you stay quite near to the startingvalue ...

For everythig more global, FoV of a rectilinear lens follows the function:

FOV (rectilinear) = 2 * arctan (frame size/(focal length * 2))

with the arctan-function as a nonlinear element in it ... for small differences

of the term within the arctan-function, you can approximate this by a linear function ...

but going from 14 mm to 24mm is nearly a factor of 2 ... that is a very long way from

being a small change.

For a better and in depth explanation .. see here:

http://en.wikipedia.org/wiki/Angle_of_view