Arduino‑Based Shutter Speed Tester for Classic Film Cameras

Components & Supplies

	Arduino Micro	×	1
	0.96" OLED Display 128 x 64 SSD1306 I2C	×	1
	Phototransistor NJL7502L Spectral response closely matches the human eye, ideal for light measurement.	×	1
	Resistor 10kΩ	×	1
	Flashlight	×	1

Apps and Online Services

Arduino IDE

About This Project

This guide explains how to build a compact shutter speed tester that lets you verify the shutter speeds of classic film cameras. The tester uses an Arduino Micro as its controller, a 0.96" OLED display for output, a phototransistor to detect light passing through the camera lens, and a simple flashlight as the light source.

When a camera shutter opens, light from the flashlight passes through the lens and is detected by the phototransistor. The Arduino reads the resulting voltage change, calculates the exposure duration, and shows the measured shutter speed on the OLED screen.

How to Use

1. Place the camera on a flat, stable surface.
2. Open the camera’s back cover to expose the shutter mechanism.
3. Position the tester so that the phototransistor faces the camera’s lens.
4. Place the flashlight behind the camera and aim it through the lens toward the phototransistor.
5. Power the tester with a USB supply.
6. When the startup screen appears, release the camera’s shutter. The measured speed will flash on the OLED display.
7. Repeat the process to confirm additional shutter speeds.

Tips & Customisations

Choosing a Phototransistor: If you prefer an alternative component, review its datasheet for spectral response and sensitivity. The SFH309‑4 worked well in our tests without schematic changes.

Using a Different Arduino: Any Arduino board with an analog input will work. For example, a Seeeduino Xiao (3.3 V) can be used by connecting the phototransistor to pin A10 instead of A6.

Code

Download the complete firmware and examples from our GitHub repository:

https://github.com/hiroshootsfilm/shutterspeedtester

Schematics

All schematic files are available in the same GitHub repository mentioned above.