Powershot and CHDK for Timelapse

I’ve been using canon powershot cameras with the CHDK script for a few years now, with great results.

Some tips:

  • do your calculations. Think about how long you want the final piece to be in video-length, over what time-frame. Generally people (myself included) end up recording WAY WAY TOO MUCH. Then just throwing it away. Or, worse, the card fills up and stops because you’ve set the frequency too high.

  • record at 1600×1200 resolution. This is very HD video. Unless you’re thinking of panning on a frame, you can record exponentially more frames than the full 10 megapixels or whatever the camera allows.

  • save battery by turning off the screen before starting. This can be tricky, because you have to remember the shift-toggle to turn on CHDK, and can’t see anything as it shoots. But saves a ton of battery. (you can hear it clicking away)

  • turn OFF preview. In the menu, there’s settings for “preview last shot for X seconds”. This slows the speed down greatly. Turn it off. Here’s a quick start for using it.


    (NOTE: this is for an SD card that’s got the CHDK script working, with auto load on the card set up correctly.)

    read about CHDK firmware on a canon powershot camera

    START RECORDING: (SD card in LOCK position, camera should have auto-load CHDK setup already. This can be tricky, and, often I skip this by just updating the firmware manually every time I turn it on. It becomes set camera to play. turn on. menu. up once. set. right. set again for okay. wait 3 seconds, chdk splash screen should appear. then switch camera to record mode. now print is the alt button for working with the chdk script)

    – plug camera into AC adapter.
    – Turn camera ON to Record mode (vs play mode. again, must have chdk set to auto load)
    – Press the ALT button (flashes blue when you turn the camera on)
    – Press the shutter release, and the intervelometer script will start recording

    To stop it, press the shutter release again.

    Download photos:

    – remove SD card
    – set it to unlocked position
    – put it in a computer (via card reader)
    – browse the card; move the DCIM folder on the card to the computer
    (leave all other files and folders on the card)

    – put card back in camera. Repeat.

    IMPORTANT: card MUST be set to LOCKED when in the camera.
    (everything below is cookies…ignore if its all working fine using the auto load chdk function. However, a lot of this is general troubleshooting the CHDK firmware operation)

    – The ALT button works like a SHIFT key when the script/firmware is loaded; changing the camera controls to the CHDK scripted mode, with all sorts of additional menus and settings. To pull up this menu, the camera must be in ALT mode (on the camera display, you see this in the lower left: when in ALT mode, the name of the script you’ve loaded or a block graphic).

    Pressing “Menu” when in ALT mode brings up the CHDK menu with a long list of options.

    Primarily the thing you’ll need to set in this is the script parameters.

    – turn on the camera.
    – go into ALT mode (script title on blue indicates you’re in ALT mode)
    – press menu
    – use the direction controls, navigate down to “Scripting parameters”, and adjust the seconds/minutes.
    – press menu again to exit

    – to see what you’re capturing, turn the camera to PLAY. Use the joystick to review. Be sure you’re not in ALT mode (CHDK) when reviewing photos.

    – IF on the display, you see, “RAW: ###” on the right, you’re saving every photo in RAW. This takes up a ton of space, and should be turned off.
    – In ALT mode, toggle this to off by pressing “FUNC” button. The “RAW: ###” text should disappear. Its easy to forget this, and its easy to flip it on…so keep an eye on this.

    Something’s not working. Check that the card has the files on it below.
    – possibly the scripting files on the card were removed. Use the other card and restore the files. The card root structure should look like:
    > CHDK (folder with lots of stuff in it)
    > DCIM (where images go)
    > DISKBOOT.BIN (a file)
    > PS.FIR (a file)
    > UpgradeLog.txt(a file)

    If the card doesn’t auto-boot up with the hack script (ie: when you turn it on, and press the ALT button, the script title on blue doesn’t appear in the lower left)
    – card must NOT be locked to do these next steps
    – with camera OFF, turn camera to play
    – Press menu
    – scroll down to Update firmware (last item)
    – hit okay. camera reboots, and you should see the blue background with white text saying its loaded the firmware.
    – without turning the camera off…turn the camera to record (take a photo).
    – now, pressing the ALT (print) button should allow for the script menu to be accessed.

    – the card in Locked setting (physical switch on the card), allows for the script to be auto loaded. If the card isn’t locked, it won’t auto load the script/firmware. See MANUALLY UPDATING FIRMWARE above.
    – it should be fine in LOCKED mode though, so most of this should be irrelevant. However, I often will not lock the card, and just manually update firmware every time I turn the camera on. Its quick when you get the hang of it.

    – the script will shoot until the card is full. After it fills up, all bets are off on what will happen. It may overwrite shots, but I think it just stops recording. Watch your script. If you open the script text file, you can easily make one that is say, 9000 photos, then stop. Save it, drop it in the chdk/scripts/ folder, and load it up.
    – be sure the camera is recording in low size/compression settings to save space:
    – turn camera on
    – NOT in ALT mode, press the Function button
    – browse the menus and set the resolution to 1600×1024 (or lower);
    – you can use any of the settings on the camera, including flash, zoom, manual exposure, or whatever…BUT, if you’re in ALT mode, none of the settings will work. Get used to hitting that ALT *(print) button to go to regular mode, zoom in, set aperture, etc…then hit ALT mode, and press the shutter to start the script.

    – the 2 SD cards will ONLY work with a lot of powershot cameras. The info above is specific to the Canon Powershot camera runing the appropriate CHDK script found at:
    CHDK firmware site

  • Mounting mirrors

    Mirrors go with projectors just as much as lenses do, but typically are difficult to work with as they are fragile, sharp, and can be tricky to mount and position.

    I came up with a pretty easy method of mounting positionable mirrors with projectors, after WAY too much trial and error. This method is for pretty small mirrors, depending on weight..but probably would only be good for mirrors up to 8″x8″.

    1. Goop glue. Don’t use anything but this. Epoxy is so so, but a bit too brittle. Goop is the best, it has a bit of flexibility. Not rubber, but a bit more movement. Epoxy doesn’t have any, so if you bump it just right, often the whole thing will come apart in one pancake of epoxy.. (just get Goop, any hardware store).

    2. helping hands from electronics store. The ‘Shack would be the worst place to get these, but they have them. best is your local surplus store.

    3. Mirror. Often a good hardware store will sell mirror tiles in a box. They’re thin cheap mirrors, but no big deal if they break. And, optically they’re fine.

    4. glass cutter – again, any hardware store

    Depending on how many mirrors you’re thinking, you’ll want to get probably numerous helping hands. Although you can use the alligator clips that come with them to hold the mirror, its a bad idea…I tried this first, even adding some gaffers tape so the alligator would have something to grip to. also you then see the clip in the projections. Not so great. Much harder to position as well.

    The helping hands joints (thumb screw elbow connectors)…they don’t need to be gripping a little mini ball like they come with..but can also grip a screw head. So one method is to glue a bolt and screw to the back of the mirror, and use the helping hands ball joint grabber to grip a screw head. You then need fewer helping hands, as they come with 4 (I think) joint connectors. So basically all you end up using from the helping hands is the joint connectors. I’ve tried finding these alone, but can’t source them.

    The results you can get from a single projector with multiple mirrors is fantastic.

    Build a Portable Screen

    Portable 10′ x 7′ screenI do a lot of projection installations, in unique locations, usually with about zero setup time. When I looked into buying a professional 10’x7’ “fast-fold” screen, I was blown away by how much they cost. Instead, I decided to design my own, using easy to find materials.

    The Challenge:
    1. Fast to set-up
    2. Fits in a cab
    3. Front or rear projection
    4. Affordable

    Sewing machine
    Pipe cutter ($20 most hardware stores)

    Aluminum Electrical Conduit ($11 for 10’ pole)
    4 Aluminum Elbow Joints (”Speed-Rail” brand, 1” dia. roughly $10 each)
    Front Projection Material (Dazian in NJ, $110 for 9’x7’)
    OR Rear Projection Material (Dazian again, $170 for 9’x7’)
    Lycra Fabric (strong, not thin stuff), stretches in both directions (most fabric stores, $16 for 3 yards)


    1. Once you have all the parts, lay out the screen material.

    2. Cut out the stretchy lycra material 12” wide by 7′. You’ll need two strips this size. Its what keeps the screen tight to the frame.

    3. Put your sewing machine on wheels. I used a 1’ sq. piece of pegboard with small wheels attached. Its a lot easier to move the sewing machine than the whole screen and lycra roll. Sew the seams

    4. Pin the lycra to the screen, with about 2” overlap on the front and back, sandwiching the screen material between lycra. You’re making a sleeve for a pole to go through, tent-style.

    5.Wheel the sewing machine along this seam, with a very wide zig-zag stitch. Don’t over-sew, as the screen material has a tendency to rip when there’s too much stitching. Thicker thread is better for the same reason. Again, fewer stitches is stronger, as the vinyl can rip easier with a lot of holes in it from too many stitches

    6. Cut the aluminum conduit. Allow for space to stretch the lycra. Poles should be about 6” wider than your actual material (3″ per side). This is a very tricky step, and may require cutting the pipes to allow the screen to stretch enough, but not too much, on the horizontal. Cut them down in small increments until the screen is held tightly by the lycra.

    Completed Joint

    That’s it!

    To make the screen cab-ready, the poles have to be cut down to 5’ lengths. Luckily, aluminum conduit comes with couplers and screw ends, and the 10’ poles can simply be cut in half. The 7’ poles cut down as well, but you have to cut out the middle 3’, so you can keep both ends.

    If you need it to be free-standing, cut some small poles and put them perpindicular to the screen in the elbow joints. If you need it hung up, use an eyehook in the speedrail joint instead of the allen wrench screw. I often will get rid of all the allen screws, replacing them with eye hook screws, so I don’t have to track down an allen wrench at 6 in the morning when tearing down…sigh. We learn….

    This screen design comes from lots of trial and error. It looks very professional, but costs so much less than a 9′ x 7′ pro screen. And, because all the parts are pretty easy to find, its simple to adapt the frame to different screen sizes.

    Here’s some photos of a 12’7′ rear projection screen for the Zero Film festival we built with the method above.

    Build a Projector Mount – Interface with Architecture

    I’ve been doing projector installations on the fly for quite awhile, and have seen just about every method out there. For portability and speed, nothing beats a thick steel plate, with holes drilled in it where the projector mount screws align, and some easy to find hardware. In the middle of the plate, I put a standard tripod nut or bolt (1/4″). If its a nut, use JB Weld to glue the nut to the back of the plate, after drilling through of course. Then, you can easily attach a Manfrotto super clamp and from there, to a a pipe clamp. Or to a tripod, or any standard lighting/photography gear (arms, ball heads, security camera mounts, etc. they all use 1/4″ screws).

    The key to all this is the plate. Most sub-10lb projectors can get by with just two of their screws holding the projector up, assuming you’re hanging the projector horizontal or close to it. Build an X or a triangle if you need something stronger. On my 4200 lumen projector, I build an “X” to hit all 4 mounts, with a tripod-sized bolt holding it together in the middle. Not only is this WAY cheaper than the “ceiling mount” junk out there, its also low-profile, allowing the projector to fit in its original case by just unscrewing it like you would a camera to a tripod.

    On the larger projector, I mounted a quick release plate, and put a second screw through, so it will never turn and loosen. This allows the projector to be mounted at any angle. Note: some projectors I’ve been told won’t operate vertically, although I’ve never seen this.

    The manfrotto clamp
    Generic pipe clamp
    (great for going around pillars, or other architectural features)

    Oh, and you’ll need a ball head for aiming. Manfrotto has fancy one’s, but you don’t need anything expensive for smaller projectors. Slik is usually fine. Here’s some info on them

    Combine this with a VGA transmitter, and your installs are a snap. No long runs, no gaffing cables down, no stands to fall down.

    Here’s this setup in a timelapse for IPR’s canal-closing with Share. Notice the projector mounted to the pillar? Took no time to install.

    Hope this helps you get in and out of your gigs quick and easy.

    Here’s one I set up holding a projector on a wall, bouncing off a convex mirror to hit an entire ceiling at the Time’s Up 20th anniversary.