UBASIC/Scripts:Long Exposure Intervalometer

Written for/on: Powershot S3 IS

Also works on: Powershot A560 (probably others as well), A720IS (Tested).

Here's the script I've been using to take long exposures all night long. [Chuck's CHDK Timelapse vids] I've used it on both my A560 and my S3 IS. They both seem to work pretty well. The set_prop to turn the display off doesn't do much on the A560. It blanks the screen on the S3 while it's taking the pic (that could just be what it does anyway)

I'd like to add some sort of exposure monitoring so that when the sun comes out it will either set the exposure to 'auto' or just stop capturing. (That way I don't have to wake up at the crack of dawn to turn it off) It doesn't take much morning light before the entire ccd is saturated white.. I can't imagine that that's very good for it.. The ultimate would be to code up an 'extreme auto exposure' where it would do 65 seconds at night, and then go all the way over to the high speed shutter if the sun entered the pic during the day.

I'm using recent Allbest builds for this... http://malbe.nm.ru/chdk/ Allbest quick reference Allbest firmware usage

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Script Code (save as "long-exp-clicker.bas" to your /CHDK/SCRIPTS/ folder)

rem Author - Keoeeit
rem ReAuthor - Chuck
rem USE WITH CAUTION
rem do not run for many hours or days
@title Non-stop Long Exp Timelapse
@param a Interval (Minutes) 
@default a 0 
@param b Interval (Seconds) 
@default b 30
@param c Interval (10th Seconds) 
@default c 0 
@param d Initial Delay (Seconds)
@default d 3 
@param e Noise reduction (0=auto 1=off 2=on)
@default e 1
@param f Capture Raw Image (0 or 1)
@default f 1 
@param g ISO (-1=hi,0=auto,1=80,..,5=800)
@default g 1 

t=a*60000+b*1000+c*100 
 
if t<100 then let t=5000 
 
n=1 
 
print "Interval shooting."
print "Until you interrupt it."
print "Use with caution."

sleep d*1000 
 
rem Display mode off
rem 181 Display mode (Valid for record mode only) 0 = Show info icons, 1 = Do not show info icons, 2 = LCD is off, 3 = EVF.
rem This didn't seem to work for the A560
set_prop 181 2

goto "shot" 
 
:shot
  print "Shot number", n 
  set_raw_nr e
  set_raw f
  set_iso g
  set_tv96_direct -576
  shoot 
  n=n+1 
  sleep t 
goto "shot"

Now that I posted this, I found a more configurable script: Shutter Speed Stack (AllBest build)

And here's a forum thread with settings for it.. [1]

Chuckheron 15:12, 19 February 2008 (UTC)