Canon EOS 350d DIY Radio Controlled Shutter Release

** See disclaimer at the end of this page **

This page details how you can construct a radio controlled trigger device for any Canon camera that uses the 2.5mm remote release (e.g. 350d, 300d) or indeed, to trigger the Portaflash series of studio strobes that also use a 2.5mm trigger socket.

The DIY bit is a little bit of a misnomer as this project involves hacking a bought radio trigger system.

But why?

I use mine to trigger a 2nd camera on hitting the shutter release on the first, therefore giving me the option of 2 different angles for the same shot. You can also fire the radio trigger manually (with a range of up to 30m) letting you take group shots without being tethered to the camera or having to race the timer to get yourself into the frame. You can use it triggering the camera where your presence would otherwise be obtrusive - e.g. bird watching. You could use it to place the camera in a position you wouldn't be comfortable shooting from yourself. etc etc.

You will need:
A radio trigger system
A 2.5mm mono jack plug
Some wire cutters
Perhaps a soldering iron
Some insulation tape

My radio trigger was sourced from a trader in Hong Kong via eBay. Check out seller link-delight (a first class ebayer who you should have no problems with at all) and search their items for "Radio Slave Wireless Remote Flash Trigger for Studio". This box of tricks is a single channel, dual frequency radio transmitter and receiver that terminates in a 1/4" jack plug.
Basically, you need to remove the existing jack plug and attach a 2.5mm jack plug in its place. Fortunately, in the supplied pack, you get a PC to 2.5mm adaptor cable which conveniently gives you the required plug!

Bare the wires of the cable that comes from the receiver. They should be colour coded red and white. If not, use a multimeter to test the 1/4" socket for which colour goes to the tip of the connector. With mine, this was WHITE.
If you are using the PC -> 2.5mm cable, remove the PC socket and again, bare the wires. Check and note the polarity (again, white goes to the tip of the 2.5mm plug)

Now, join the pairs of wires (twist or solder), observing the correct polarity (this may not be necessary, but why not just get it right to begin with?)
If you elected to not use the supplied PC -> 2.5mm cable, attach the wires from the receiver to your 2.5mm plug, with the white (or whatever colour yours happens to be) wire going to the tip. The red wire goes to the barrel.

Use the tape to insulate the joined wires and go play!

Using the trigger
As this is effectively only a single switch, we can only use the unit to fire the shutter. This means you will need to pre-focus on your subject and flick the lens into manual focus mode. Once you have done that, plug the 2.5mm plug into the camera and switch the receiver on. The shutter may fire once. To prevent that happening, turn the camera off while you connect the receiver to the camera.
Turn your camera on and try manually firing the shutter by pressing the button on the transmitter unit.
It's assumed you've put batteries into the receiver and have the transmitter and receiver set to the same channel ;-)

Here is a pair of photos from the first use in anger of the system on the Leukaemia Road Rally 2006. The first shot is from the 10d I was holding (the transmitter unit being connected to the hotshoe of the 10d), the 2nd from the remotely triggered 350d.
I had originally tried getting a front and rear shot, but the dust being kicked up obscured the cars

Not too bad for something that cost about £15!


Neither myself,, my family, my friends, my pets or my arachnophobic anteater take any responsibility whatsoever for any damage caused to anything or anyone by duplicating what I've done. If you feel confident in not destroying your expensive digital imaging equipment by trying this little ditty, that's your choice and not mine.

v1 10th March 2005  

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