HDR with stacking[]
Tested on the S3IS, A540 (CHDK beta build), A570, A720
If you stack (around five is a good number) photos, you can virtually eliminate noise - by stacking them in PS. This script will take as many repeating shots as you want, bracketing the currently selected LEFT/RIGHT action by as many steps as you select. In Manual Mode, that'll be for Shutter Speed - but you could use it in any mode, as long as you had 'Exposure adjustment' in focus on the screen.
Script Code (save as "hdr-stack.bas" to your /SCRIPTS/ folder)
@title M Mode HDR Stack
@param a Number of steps
@default a 2
@param b Step size (1/3EV)
@default b 3
@param c Number of Shots
@default c 5
if a<1 then let a=2
if b<1 then let b=3
if c<1 then let c=1
sleep 1000
print "Preparing..."
for n=1 to a*b
click "left"
next n
for s=1 to a*2
print "Shoot", s, "of", a*2+1
for r=1 to c
shoot
next r
for n=1 to b
click "right"
next n
next s
print "Shoot", a*2+1, "of", a*2+1
for r=1 to c
shoot
next r
print "Finalizing..."
for n=1 to a*b
click "left"
next n
end