Canon Camera Hackers Manual page 154

"%u of %u, MET %u:%u:%u.%u",
frame, n, h, m, s, t))
end
if sleep_until(next_event) then
print "Aborted"
break
end
end
-- restore display mode
set_display_mode(old_display_mode)
-- restore AF lock mode
set_aflock(0)
This script is very precise because it always computes the time of the next
event and determines the sleep time as the difference between the next
event and the current time. Even long exposure times do not disturb the
script's timing—provided, of course, the exposure times don't exceed the
defined delays between shots.
Time-lapse movies
Time-lapse scripts are often used to create time-lapse movies. Of course,
your camera probably offers a built-in function to create time-lapse movies,
but it is rather limited. Let's see what's possible with a time-lapse script.
First, with a script you don't work in video mode but in photo mode.
This allows you to step up the image resolution. High Definition (HD)
movies (1600x1200 pixels) become possible, and wide-screen movies
(16:9) are no problem. When creating a time-lapse movie in this way, you
should shoot in JPEG mode (not RAW). RAW files take up too much space,
and the programs used for composing the movie expect JPEG.
Select an image size large enough to cover the output format. Output
for normal television (NTSC) needs a resolution of at least 720 x 480 pixels,
so the M3 image size (1600x1200) should be more than enough. The same
image size is also sufficient for 4:3 High Definition (HD) movies. However, if
you plan to create a wide-screen movie (16:9), you should use image size W
instead. Wide-screen HD requires at least 1920x1080 pixels, so image size W
is more than enough. In addition, your display is switched to the wide-
screen format when using image size W.
Both formats (M3 and W) offer you different compression ratios. I prefer
to start at medium resolution. The compression ratio "Superfine" is hardly
necessary for a movie. With a 4 GB card, you can expect the following play
times at 30 fps:
5.7 Example scripts
145