In this instructable I will be showing you how I made a shutter release cable for my Nikon D3200, although the procedure may be adapted for various other makes and models. This shutter release cable replaces the Nikon MC-DC2 and makes use of an adapter cable which has the shutter release connector on the one end and a 2.5 mm audio jack on the other end. The device has three buttons: One button for focusing, one button for taking a single exposure (which must be pressed simultaneously with the focusing button) and a third latching button for taking long exposures in bulb mode.
Step 1: Parts required
The following list shows the components that I used. The adapter cable I bought through ebay and this is advertised as a cable which converts a flash transceiver into a wireless shutter release device, but we will be using it to make a shutter release cable. The other components can be purchased from any electronics store.
Some components can differ slightly in terms of size and shape, but the important part is that the push buttons should be push-to-make, two of them non-latching (momentary) and one latching. A latching switch is one that stays on until you press it again, while a non-latching switch is only on for as long as you hold it down.
- One 3N-X Remote Switch Shutter Release Cable for Nikon (e.g. this one) with a 2.5 mm audio jack on the one end. Cost: 2.06 USD (30.24 ZAR) including shipping
- One small enclosure (60 mm x 35 mm x 18 mm). Cost: 18.73 ZAR (1.30 USD)
- One panel mount 2.5 mm stereo audio socket. Cost: 10.50 ZAR (0.73 USD)
- One panel mount N/O momentary push-button switch (red, M6.9). Cost: 11.91 ZAR (0.83 USD)
- One panel mount N/O momentary push-button switch (black, M12). Cost: 22.37 ZAR (1.55 USD)
- One panel mount N/O latching push-button switch (red, M12). Cost: 23.88 ZAR (1.66 USD)
- Two signal diodes (BAT85, although others may also be suitable). Cost for two: 5.16 ZAR (0.36 USD)
- Stranded panel wire which can be bought or salvaged from old electronic devices.
Total cost: 122.79 ZAR (8.52 USD)
Step 2: Plan the layout and drill the holes for the connectors
In order to fit everything into the enclosure it was necessary to place the connectors on the sides of the enclosure, but this actually also makes sense when you look at the way the device will be held, with the index finger on the focus button and the thumb on the shutter or bulb button.
The enclosure I chose is split into two halves right in the middle, which made drilling the holes a bit more challenging. For the larger holes I found the plastic soft enough to use a smaller drill bit and work the holes until they were large enough to fit the push buttons.
Step 3: Wire and solder the circuit
The figure above shows the schematic for the device. The concept is simple: The camera focuses when the middle ring on the 2.5 mm connector is connected to the sleeve (ground), and takes an exposure when both the tip and the ring are connected to ground simultaneously. The focus and shutter switches are therefore responsible for making this connection, and both need to be held down for an exposure to be taken.
For the bulb switch we use a latching switch so that we don't have to keep the button held down by hand for long exposures. This switch should connect both the tip and the ring to ground. However, we have chosen to use a single pole switch and we cannot simply connect the tip and ring together before passing it through the switch, since this means that if the focus button were to be pressed, the tip would also be connected to ground since it is connected to the sleeve, causing an exposure to be taken instead of just making the camera focus. In order to solve this problem we make use of two diodes which ensure that current only flows from the tip and ring through the bulb switch to ground. Current will not be able to flow from the tip through the focus switch to ground, since that would require current to flow from the tip through the first diode, and then downwards on the diagram through the second diode which is not possible. An alternative to using diodes is to make use of a double-pole switch (e.g. a double-pole toggle switch) which connects the tip and ring signals to ground without connecting them to each other (see here).
The connections should be made using the panel wire and soldered in place. In the picture black represents ground, yellow represents the focus signal and red represents the shutter signal. Note: Where applicable, make sure that you place the connectors in the enclosure first with the nuts on to ensure that the wires run through the holes and the nuts. Some push buttons are inserted from the outside and not the inside and if you solder the wires while the connectors are on the outside, there is no way of getting the wires through the holes. In my case the holes were made up of two halves which meant that I could solder the circuit first and then place it in the enclosure, but this might not always be the case.
Step 4: Finishing up
The final step is simply to fasten all the connectors and close up the enclosure, plug the adapter cable into the shutter release device and camera, and start shooting! If you like, you can extend the length of the cable by buying or making a 2.5 mm stereo audio cable with one male and one female connector. This would then be connected in between the adapter cable and the shutter release device.
For more information on the shutter release connector pinouts for various other camera makes and models, see this webpage.