A cable shutter release is one of those camera accessories that for me, isn't entirely necessary, but is something that may prove useful to have, e.g. for if I ever get around to taking photos of the stars. I wasn't going to fork out the money to buy one, especially since it was is something that I don't absolutely need, and being a photographic accessory, they don't exactly come cheap (but then again, what photographic accessory does?)
So, I thought about building one myself, and looked to see if there were any instructions. It turns out that a cable shutter release mechanism is actually very simple, and it wouldn't be overly difficult to build one. In fact, if you have even the slightest bit of soldering skill/electronic skill, you should have absolutely no problems with building one. And it comes cheap too. The parts, from a local electronics store, came to a total of just A$6.35, (~US$5.50).
So how do you build one?
Firstly, to read up on how a cable shutter release works: click here
And then try here and here for the instructions.
And then using the information from the sites listed above, I created this:
This is my circuit diagram. Operation is very simple. Press the blue button for AF. Press the red button for the shutter. And for bulb mode, flick the switch to open the shutter, and when I'm done with the exposure, flick it back.
When you look at the cost of the bits and time to make a unit that is easy to use, why not just buy the dam thing?
I would, however, like to add a comment and hope that some others pick up on this.
As opposed to switches, why not add a little more electronics, timers etc, and look at making a radio trigger, lightning trigger, dime delay or very long time exposure options.
I have seen other posts fo people looking for time delay shutter release, or the ability to trigger the shutter from the opposite side of a bridge.
As opposed to switches, why not add a little more electronics, timers etc, and look at making a radio trigger, lightning trigger, dime delay or very long time exposure options.
It doesn't trigger autofocus, nor is it easy to use bulb mode for extended time - if you need that kind of thing.
Ummm... did you even look at the product description ?
It has the half depressed position that triggers autofocus, and also a locking mechanism for bulb mode. Have used it myself quite a lot.
I know the feeling
I once made a primitive stand for my telescope (a plastic childrens one, but my age was also not so wrong for it then ) from a christmas tree stand, some vacuum cleaner tubes, a bicycle tire pump handle, transistor heat spreaders etc. etc. That was really fun !
hm I though of making my own and yes they can be easily expanded using basic electronics to create lots of custom things the 555 timer is so easy to use I mean you could set it to take pictures at regular intervals for example I saw something like that for sale and they wanted fot it much more than it was worth something like 50 quid, erm is that second link saying that any old remote will work ?
Here is my version... all parts were either from my junk box, or recycled from broken junk.
Pat
I'm thinking it's time for me to grub through my junk box and work up something like this. I like how you used two different button types so it's easy to know what you're pushing without looking.
) from a christmas tree stand, some vacuum cleaner tubes, a bicycle tire pump handle, transistor heat spreaders etc. etc. That was really fun ! 
