How to make an inexpensive SLR camera cable release using an old cellphone headset .
If you own a Canon DSLR and need a remote cable release you can buy one from sources like this one at Amazon. It's a relatively inexpensive item (as photography items go). However, it is possible and quite easy to build your own using rather inexpensive items. This article shows as an example how you can build one using an old cellphone (corded) headset.
After seeing some connection examples on the web, I realized that the circuitry involved in the cable release for Canon DSLRs is quite simple. There's a 2.5mm jack that connects to the camera (in my case a Rebel XSI/450D).One switch connects the sleeve to the tip to activate the shutter. Another switch connects the inner ring to the sleeve to pre-focus. You can certainly connect both switches but in this case I just connected the shutter release button. the camera will focus before releasing the shutter anyway. However, if you want precise focusing, you could set the lens to manual focus mode and pre-focus before releasing the shutter.
Your old headset normally already has a 2.5mm jack. You just need to open it and make sure that the connections (tip and sleeve as indicated in the Figure above) connect to the push button inside the headset. I recommend using a multimeter to find the correct connections and solder these two signals to the push button inside.
There might be other connections inside the headshet and, in some models, an eletrect microphone. Simply remove all these extra components. All you need is tip and sleeve connected to the push-button.
The figure above shows the complete, assembled cable. I've used this with a Canon Rebel XSI successfully and, based on other user experiences I read on the web, this should also work with other Digital Rebel models. And there you have it; a simple and inexpensive cable release that you can make on your own and costs you next to nothing!
Comments, questions, suggestions? You can reach me at: contact (at sign) paulorenato (dot) com