A visualist with a digital camera is stop-motion video just waiting to happen. Since gaining access to a Pentax *IST DS digital SLR I’ve hacked together a functioning cable release which produced reasonable results. This was a very inelegant setup, though simple, and I feel it may put undue stress on the shutter mechanism. So I’ve been looking around for something which would allow variable-interval timelapse shooting, but not cost as much as a professional timer switch, or intervalometer.

Et Volia!

Australian electronics-nerd supplier extrordinaire Jaycar Electronics has the Countdown Timer project for AU$12.95 (+$2 for the beautifully photocopied instructions). It’s not a precise timer – the digital version costs much more – but it is adjustable from ~15 seconds – 5 minutes.

I’m no solder-ninja. The last circuit I put together was a crystal radio, and it didn’t work. This looked reasonably straightforward though, and I have the benefit of an excellent assortment of electronics equipment lent to me by a friend who didn’t know any better.

US readers looking for a similar kit are spoilt for choice. Here is a particularly attractive one.

Putting the kit together was relatively straightforward. After a quick soldering primer things progressed quite quickly. The colour codes of the supplied resistors didn’t seem to bear any resemblence to the values required, but fortunately I had a multimeter handy which allowed me to identify which one went where and get everything together.

Aaand it worked first try. Pressing the reset button turned on the LED with an audible click from the relay, and a collection of seconds later it turned off. Excellent. Now I needed something to plug into the camera.

It appears that most cameras – both SLR and Point&Shoot – just use a 2.5mm stereo mini-jack to connect a cable release. One side triggers autofocus, the other releases the shutter. I don’t really want to use auto-focus, so I just picked up some extra mono jacks and a plug to allow my cable to be modular. I can choose to have a manual button, electronic intervalometer, or an always-on trigger which just short-circuits the jack and makes the camera fire at full speed in burst mode.

This completed, the only remaining problem was getting the circuit to function as an interval timer, rather than just a single-shot. Holding down the reset button didn’t work – the timer didn’t even start. Fortunately the relay included has both normally-open and normally-closed contacts. When the timer is up the closed side switches open and vice versa. Wiring the normally-closed side across the start button puts the circuit in a loop, as soon as the relay is triggered it closes the reset circuit, restarts the timer and opens the reset circuit in a fraction of a second.

This shot was triggered by the circuit, hurrah

Underside of PCB trimmed and tidied

Connecting the camera release to the normally closed side of the relay and making sure the camera is on single-shot mode made everything work perfectly. For the camera it’s as if the shutter is held down and released for a moment every 15 seconds. By replacing the kit’s potentiometer with different values it’s possible to increase or decrease the timer’s range, but I was happy with the factory setup and ready for a test shoot:

I learned a couple of things shooting this piece. Most importantly: Don’t use testing circuit connections in a production environment. After about 5 minutes one of the cable release wires worked its way out, which resulted in several minutes of scrabbling around frantically trying to get a connection which would hold. Also, as the lens was on manual and pointing slightly downwards it slowly lost focus. For future shoots I’ll engage autofocus mode. Autofocus won’t be triggered by the cable release, but the focus motor should prevent the lens from moving.

Next from the Timelapse Lab: Why are my exposure and colour balance varying so much?

  • Great setup…

    Your white balance is probably drifting due to lighting… particularly, if you're using a fluorescent light, the color is constantly cycling, so the white balance will suffer.

    I'd reccomend setting the SLR to full manual exposure and manual white balance, and using long shutter times (1/20 sec or longer) to try and average out the color pulsation of the light. You might also want to try a different illumination source (such as a tungsten bulb which will cast a consistent yellowish light).


  • nik

    Be careful with that rightangled 2.5" socket from jaycar, I tried 3 of them which all had a defect with the connections to one of the pins.

    This was very noticable when connected to headphones as one channel kept crackling. Eventually I had to solder over the mechanical connection for the top pin which was dodgy.

  • Mike Prevette

    Color balance fluctuation is either what Andrew said or, you were just in auto wb mode.

    Exposure fluctuation would be caused by the reflections in the ice tricking your camera into changing it's exposure (if you were in some auto mode)

    But it's far more likely (if your smart enough to build this project your probally smart enough to be in manual mode) That your camera was manualy set to an f-stop that wasn't the widest setting. Here's where it gets wierd!

    MODERN CAMERAS USE ELECTRO MAGNETS TO CLOSE AND SET THE LENS APERTURE micro seconds before the shutter opens. this allows you to view through the viewfinder at maxmum brightnes before the shot is taken. well guess what, the aperture very rarely lands in the EXACT same position, hence subtle exposure variances that aren't normally noticable in still shots, and become VERY noticable when strung together into motion.

    The solution is to either shoot at the widest maximum aperture (avoiding the stopping down) or get and adapter to use some older manualy stoped down lenses.


  • Thanks for the comments guys.

    @Andrew: I'm using 2000W of halogen work lights (and a DIY softbox, article soon). So I'd hoped these would give out reasonably constant light level. I did notice afterwards that one of them had blown, so the fluctuating levels could have been due to a dying bulb, but would that effect white balance?

    I have indeed locked everything off to full manual: exposure, aperture, white balance, even ISO.

    Here's the "raw footage" (cropped and scaled): http://www.youtube.com/watch?v=E5DQU52BtWs

    EXIF tells me that they were 1/30 at f/9.5, so Mike's explanation rings true. I'm currently looking for some fast manual lenses, but in the meantime I'll do the next test fully open, and with a new bulb.

    This is very interesting stuff though, I'll definitely be following up with a decent article on setup, so all thoughts and pointers are appreciated.

    @Nik: Thanks for the tip. It seems to be holding up ok at the moment, and it's not really sending a high-fidelity signal 🙂 But if I notice the cable failing I'll definitely know where to look.

  • Alex

    I made a time-lapse video a long time ago, but I
    used a camera which uses a IR remote control for
    the shutter release:

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  • Mike

    Mike Prevette's comment about the exposure is probably the exact reason for your fluctuating brightness. But since Pentax is the greatest at backward compatibility for their lenses, they have a way to support fully manual lenses that have no way for the camera body to set the aperture. These old lenses have no "A" setting on the aperture ring.

    So set your lens manually to some aperture by taking it off the "A" setting and rotating the aperture ring to whatever f-stop you want. Then you will have to go into the camera's menus and enable the camera to take pictures in this mode. This is under Custom Setting -> Using aperture ring -> pick #2, permitted.

    Then go to manual exposure mode and pick a shutter speed that works for your scene. Hopefully you will get more consistent exposures, since I believe this method will use a physical stop inside the lens to get the aperture to stop down to the setting you've picked with the aperture ring.

    It's worth a shot, and if nothing else, you will now know how to pick up any old K-mount lens, no matter how old, and get it to work on your nice shiny new *ist DS. 🙂

    — Michael

  • Hi! I made a counntdown timer circuit with PIC microcontroller.
    It is a real DIY project.

    You can set the timer 99hour 59 min 59 sec to 1 sec. and the bulb time also 59 min 59 sec to 1 sec.

    let's see my page..

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