Working with the CHDK ( http://chdk.wikia.com/wiki/CHDK ) for Canon Powershot cameras. Here’s a sample uBasic script for taking two sequential photos to be later combined for an Orton Effect photo.

Script to be copied to your scripts folder as orton.bas

rem Savi Technologies
@title Orton
@param a Exposure Step
@default a 3
@param b Focus Step [x6]
@default b 6

if a<1 then let a=2
if b<1 then let b=1

get_focus f
rem get_av d
rem get_tv e

print "First Shot..."
click "shoot_full"

sleep 5000

for i=-b to -1
f=6*f/(b+6)
next i

set_focus f
set_av_rel 0-2
set_tv_rel a

print "Second Shot..."
click "shoot_full"

end