Foot Switch Camera Trigger for GH4

A long while ago, I made a foot switch trigger for my Nikon camera (using this tutorial), perfect for taking overhead photos with both of your hands active in the frame. Now that I have a Panasonic GH4, a new foot switch strategy is in order!

There's no infrared sensor on the GH4, but a wired solution is just fine for my use. The remote trigger that is available for the GH4 is nothing more than a few plates of metal that connect at various points of a resistor circuit. You can make your own wired foot switch from scratch, or mod your existing remote trigger to fire at the press of the foot pedal.

For this project you will need:

• foot pedal switch
• 2K resistor
• soldering iron & solder
• wire snips & strippers
• third hand tool
• heat shrink tubing
• 2.1mm barrel jack
• 2.1mm barrel port (get both of these in one cable and cut it apart)
• small phillips head screwdriver
• multimeter
• mini stereo plug or regular remote trigger for GH4, or this hobbyking cable

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Step 1: Solder Resistor and Barrel Port

Open up the remote body by removing the two small screws on the back and prying the enclosure pieces apart. The Panasonic remote trigger connects metal plates that bypass a few resistors. I used a multimeter to evaluate the resistors involved and found the undepressed resistance to be 40K ohms. When the button is depressed half way, it bypasses one resistor and the total is __ohms. When pressed fully, another bypass drops the resistance to 2K ohms.

Strip and tin the wires of the 2.1mm DC barrel port and solder a 2K ohm resistor to one of the wires. Then solder the other resistor lead to one of the two wire connection points on the trigger circuit board, and solder the other wire to the other connection point on the circuit board.

To make room for the wire to come out the bottom of the remote body, I removed the rubber stopper and widened the holes with my soldering iron (but not the shiny tip!).

If you're making this trigger from scratch, use alligator clips to connect to a 2K ohm resistor and set up your mini stereo plug wires (stripped and tinned) in a third hand tool. Clip to short various wires with this resistor to figure out which wires trigger a photo to be taken (you can do this with a multimeter or by leaving it plugged in to your camera). Then solder these wires to the 2.1mm barrel jack (don't forget the heat shrink).

Step 2: Solder Jack and Close Up Remote

Strip the wires on the foot pedal switch and use a multimeter to verify which wires are shorted when the switch is depressed (for me it was red and white). Use heat shrink tubing and solder these wires to the 2.1mm barrel jack (I cut mine from a 9V battery connector). Snap the remote body back together and put the screws back in.

Plug your remote in and use the foot pedal to take photos! Let me know what you're shooting in the comments below.

Comments

[ChrisG485]

Just to follow up on my last comment, here's a little video to show how I used the valuable info here to get the GH4 camera triggering working in my project. THANKS AGAIN. Chris

https://m.youtube.com/watch?v=-tlME2GGbko

[bekathwia]

Awesome, thanks for sharing!

[chrisgavinfilms]

100% Thanks for this. I'm working on a project to build a DIY cine film digitizer. An Arduino controls some stepper motors and needs to trigger a DSLR camera to take a still photo repeatedly under automation.

I got the automation/control working OK with a Canon 600D DSLR but then later wanted to change this for the newer Lumix GH4 camera instead. So I bought a cheap 3rd Party remote trigger switch ("Pixel" brand) and took it apart to get the cable and 4 way (4 bands on the plug) jack connector. In my circuit a small relay closes rather than a footswitch but the idea is the same.

The canon remote trigger is simply a switch, but the Panasonic/Lumix one is a bit more complex. I tried putting just a 2K resistor in line with my switch but it didn't work. Looking again at the notes here and exploring the trigger switch I finally realised that it's important to have the 40K resistance across the camera when the switch is NOT being triggered. In the 'footswitch' case shown here where the trigger switch is being used, I guess this happens anyway, but in my case I'm trying to replicate the action with a new replacement circuit instead of adding on to the purchased switch.

I found that putting a 38K resistor in parrallel with the switch and then a 2K resistor in series worked for me. So when the switch is off there's still 40K in total resistance across the camera connection. When the switch is on, this resistance drops to 2K (when the 38K resistor is bi-passed by the switch). The GH4 seems to need these resistances in both the OFF and ON state for the triggering to work.

I hope this lengthy note helps somebody else out there, and BIG THANKS again to Becky Stern here for sharing this hack in the first place.

[MarcE38]

Hey There, can you sell me one of those and ship to Germany?

[rblume73]

This would work great for my telescope setup. I'm sure it will work with a Canon, and maybe there is way to lock the pedal down for long exposures.

[bekathwia]

Cool idea! The shutter doesn't stay open as long as the pedal is down, but rather triggers a photo to be taken with whatever settings you've got going on your camera. So for a long exposure you'd just set your shutter speed manually, then press the foot switch. Would love to see your version! =D

[MattBothell]

If you set your shutter speed to bulb would you press it once to open the shutter, and once to close it, or would you just hold it down as long as you want the shutter open?

[rblume73]

Not on a Canon, or at least my Eos T3. You set it to manual, and the shutter stays open as long as the shutter button is held down. I can set the shutter speed in auto, but the longest is 30 sec. I forgot that I have a timer remote where I can lock the button down, and the shutter stays open till I hit it again, or the timer is up.

[bekathwia]

I see! Thanks for the insight!

[mikeasaurus]

Having just invested in a new remote, I can attest that they are opening up a new world for photos. No more timed shots as I rush my hands into frame!