Introduction: Pentax (and Others) DSLR Cable Shutter Release From Hands-free Cell Phone Kit
I'm trying to get into HDR photography, which usually requires some very long exposure shots. The best way to do this is with a tripod and a shutter release. I got the tripod off Craigslist, but the shuuter release was too expensive for me, so I set off to make my own. This is inspired by this tutorial for a Canon DSLR.
Step 1: Materials & Tools
To keep this on the cheap, I kept it minimal. The most expensive item was the hands-free phone kit; on sale for $10. Check the comments. One was found at a dollar store. $1!
(1) Hands-free cell phone kit
IMPORTANT: The DSLRs take a 3/32" stereo plug. See the picture for details.
(2) Momentary buttons (two colors)
(1) Mini micro switch
(1) Enclosure, for me a wonderfully ironic 35mm film canister
Drill & bits
Soldering iron and solder
Wire stripping tools
Mad Skillz (which you have, because you're cool enough to find this)
Step 2: Break Open the Mic
Be destructive, but gentle
You may not get the same model kit, so some experimentation is required.
Inside the microphone box was a tiny circuit board hooked to 4 wires. I plugged in the kit to my camera for testing. Don't worry, there' s no current in these wires. I took my knife and shorted various combinations and observed the results. I found that two are ground wires, and the other two have functions:
By connecting the Red to a ground, the camera focused. Wonderful news.
We will now make button to do this work for us.
Step 3: Solder Up the Connections
Using the diagram below from Roger Cline, Assemble and solder your buttons and switch. Test it often to avoid mistakes. When you're done, protect from short circuits with some tape.
Step 4: Make an Enclosure
Here I used an empty 35mm film can from the girlfriend. I used the recycle symbol on the bottom to perfectly align my three controls and poked holes for drilling. Then using a similar bit to the one recommended on the button packaging, I drilled 3 holes.
Step 5: Mount Stuff
This may be the trickiest step. Maneuver the three controls toward their respective spots. A long pair of needle-nosed pliers help out a lot. Also, the switch has a little groove that the washer uses to stay straight. You'll have to see it. It can be tricky. Tighten them all down and you're set. Test again of course.
Step 6: Test and Troubleshoot
So this step is kind of unnecessary if your buttons work.
But if they don't work, don't fret. Be very patient, take it apart, and test your soldering again. That's always where it fails.
Also when you coil all the extra cable into the canister, use a bit of tape to keep the complicated end of your project inside the can.
Below is a picture of the shutter release in action!