## Copyright (C) 2019 Jens
## 
## This program is free software: you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
## 
## This program is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
## 
## You should have received a copy of the GNU General Public License
## along with this program.  If not, see
## <https://www.gnu.org/licenses/>.

## -*- texinfo -*- 
## @deftypefn {} {@var{retval} =} lens (@var{input1}, @var{input2})
##
## @seealso{}
## @end deftypefn

## Author: Jens <jens@orion>
## Created: 2019-08-27

function retval = lens (f)

pw = 2048;
ph = 1536;
d = 11.1;

a = pw/ph
dh = sqrt(d*d/(1+a*a))
dw = a*dh

%f = 12.5;
dw_norm = 36;
dh_norm = 24;

a_norm = dw_norm/dh_norm
d_norm = sqrt(dw_norm*dw_norm + dh_norm*dh_norm)
crop_factor = d_norm / d
f_norm = f * crop_factor

aov_norm = 360/pi*atan(d_norm/(2*f))
aov = 360/pi*atan(d/(2*f))

endfunction