A DIY Remote Mechanical Cable Release for a Large Format Camera

I do mainly large format photography, and I often take my own self-portrait by using my pneumatic cable release that has a long cable and air bulb release. However, I have long been thinking about how to make a more modern kind of remote cable release. In this article, I will show how I created a DIY remote cable release.

Researching DIY Cable Releases

I first searched the Internet for ideas on how others have made their own cable release and see what are the different components they have used. Primarily they will make use of:

1. A microcontroller.
2. A linear actuator that will press the traditional cable release.
3. A trigger device to send a signal to the microcontroller.

So I decided to add my own flavor to my own remote cable release.

For the microcontroller, I decided to use an ESP32 microcontroller development board. The ESP32 chip has been popular with Internet of things (IoT) devices. It has built-in Wi-Fi and Bluetooth capabilities. However, for this project, I will use the Bluetooth function to do the communication.

For the linear actuator, I found a 3D design on Thingiverse you can use of a small Servo motor (the SG90 mini servo motor) and a 3D printed rack and pinion. The linear rack will push a plunger of the mechanical cable release which in turn will trip the shutter on the lens/camera.

For the project case, I modified it out of a project case template that I downloaded from the channel of Swiss YouTuber Andreas Spiess. I customized it to my needs: mainly making some holes for the cable release, the USB port of the ESP32 board, the mounting holes for the servo motor, and the ESP32 board.

The Design of the DIY Remote Mechanical Cable Release

So here is the simple electronic design diagram of my remote cable release.

The connections are quite simple, we have the battery power (4x AA batteries) to power both the servo motor and the ESP32 board. A power switch will be used to turn on and off the circuit. The circuit should be off when not in use as the servo motor will also draw current when not moving.

The servo motor signal will be coming from a GPIO output pin from the ESP32 board. The signal will have the motor rotate by a certain angle and in which direction. This will be translated into a linear movement using the rack and pinion.

Assembly of the DIY Remote Cable Release

Once the parts are gathered, soldered and 3D printed, they are assembled together. The mechanical cable release is inserted into the case first otherwise it will be blocked by the other parts.

I designed a mobile app that uses Bluetooth to communicate with the main unit.

In the mobile app, there are four functions:

1. On mode: Immediate triggering of the cable release (shutter speed set on lens/camera)
2. Timer (10sec Delay) mode: The shutter will be triggered after 10 seconds. This is best for self-portrait shots.
3. Manual Bulb mode: At the first press, the shutter will be triggered and released at the second press (shutter speed set to B mode.)
4. Time Bulb mode: Set the duration in seconds and when the button is pressed, the shutter will be automatically triggered and released at the end of the time. (Shutter speed set to B mode.)

Coding the DIY Remote Cable Release

I use the Arduino platform to create the ESP32 program and the MIT App Inventor to create the mobile app. As I am no professional programmer, I’m sure that they are a lot of improvements that can be made. I will share both codes on my GitHub as open source for anyone who is interested in using or improving it.

Conclusion

This is an interesting project that allowed me to develop my electronics and coding skills. There are a few issues that can be further improved on:

1. Make the unit even smaller.
2. Have a way to mount this on a camera hot-shoe/cold-shoe.
3. A stronger servo motor.
4. A better rechargeable battery source.
5. A digital output to trigger some digital cameras.

You can see the DIY remote mechanical cable release in action in this video showing the build and a test shoot:

About the author: Cheng Qwee Low is a (mainly) film photographer based in Singapore. In addition to using cameras ranging from 35mm to ultra-large-format 8×20, Low also enjoys alternative processes such as kallitype and albumen printing. The opinions expressed in this article are solely those of the author. You can find more of Low’s work on his website and YouTube. This article was also published here.