The PhotoPlug is a small light sensitive sensor which plugs into the headphone-jack of your smartphone*
Together with the Shutter-Speed App (available FREE on the iOS and Android AppStore) it transforms your smartphone into an optical shutter speed tester for analogue cameras.
Compact - and therefore portable - this is an invaluable tool for quickly assessing how well your cameras are firing. You can also carry with you to charity shops/car boot sales so you can make an 'in-field' assessment before purchasing.
*If your phone doesn't have a jack then you can use the official USB-to-jack adapters from Apple, Samsung or similar. Please note that cheap adapters (i.e. that don't transmit microphone input) will not work with the Photoplug
Download the free App
Download the Apple app: here
Download the Google app: here
How does it work?
Once you have plugged the photoplug into your smartphone and taken a measurement, the App will display the measured shutter speed of your camera. It will also calculate a deviation value in f-stops.
Example in the picture below: You selected 1/125sec on your camera. Your measurement tells you it is actually 1/80sec. This results in an overexposure of 2/3 f-stops!
How to take a measurement
Open/Remove the camera back.
Point the camera against a bright light source.
Position the PhotoPlug behind the camera shutter.
Press the aperture symbol (it will turn red) and release the camera shutter.
The App displays a waveform with two peaks.
Zoom into the signal (two finger pinch) to maximize the signal to the full screen width.
Select the target shutter (the speed you set on your camera) on the bottom left corner.
Use the two blue sliders to measure the distance between the two peaks. Measure from the start of the first to the start of the second peak.
Select “Save Measurement” to save the measured shutter speed. You can select from a list of cameras, that you previously added in the “Camera Manager”
You can override individual values by saving another measurement to the same camera and shutter speed.
After you saved the data, you can view it in the Camera Manager.
The Correction value is given in thirds of an f-stop. “+1” tells you to open the aperture by 1/3 f-stops in order to get a correct exposure. On the other hand “-2” tells you to close the aperture by 2/3 f-stops.