DIY: 1980s Flash to LED Fill Light
Infrared synchronizers are typically used to trigger other flash units while not participating in the exposure themselves, as shown in the image below.
It's rare to find a flash that uses a AA battery; based on this packaging, it might be from the 1980s.
This is essentially a flash unit, but instead of a transparent diffuser, it has an infrared filter to trigger other lights without contributing to the exposure itself.
The back of the unit is quite simple, with a switch and a test button. When turned off, it discharges the flash.
Once you insert the battery, the indicator light comes on, but it won't flash.
Open it up:
The right side is a standard flash unit.
A high-voltage capacitor has a detached lead.
The switch section activates the flash when turned off.
The structure is not complex but very compact. If you have one of these, you could consider modifying it into a dimmable constant-light LED fill light in the next DIY article.
