Not always in photography can be limited to using only flash. By creating different lighting schemes with multiple synchronized bursts, can significantly improve the results.
The device can be connected to Sync virtually any electronic flash. This will enhance its light pulse, formed the main flash (built-in camera, or directly connected to it).
As a slave unit can be used:
* Any of the old Soviet outbreak;
* Flash from a disposable camera or a cheap soap dish (you can keep $ 10);
* Cheap manual flash (for example, Unomat Polo will cost only $ 15);
* Any super-duper flash, Sync to which there is access.
Of course, you can purchase and corporate synchronizer. However, in this case must be prepared to pay $ 40-50 for the imported unit or $ 15 – for the Russian. At the same time no one can guarantee that it is compatible with available flash (unless, of course, the flash and the synchronizer are not the products of one manufacturer and the consistency clearly stated in the passport product).
Circuit solutions with thyristors and differentiating the chain is fairly well known and provided in a number of publications (including the internet). A special feature of this modification is the presence of a separate power source in the circuit of the photodiode.
This solution allows you to connect Slave even to those outbreaks, which cease to function when you try to pick up even a negligible current from the Sync. These outbreaks include, for example, SEF-2. At the same time, this device has elevated resistance to false alarms and reliable closure of Sync light pulse master flash unit.
As the photodetector can use various photodiodes and phototransistors. I used OS351 simply because he was under my arm. I think that FD24K also quite went to.
Battery GB1 can be almost anything. Since the current consumption is small, suitable, for example, every hour battery-tablet. It is possible that the sensitivity of the Slave depends on supply voltage. I suggest to check it yourself.
When choosing the thyristor should be aware that it should be calculated on a sufficiently large voltage, which in Sync can reach 350 V.
It should also take into account that the operation of the device, it is necessary that the voltage across the resistor R1 does not exceed 70% of the battery voltage supply. In the premises, this condition is usually satisfied.
With minor changes the same scheme can be used as an adapter, which lowers the high voltage to Sync some flares. But this theme of a separate article …
The author assumes no liability for any damage caused by industrial self-refining devices and / or unofficial connection.
I thank Paul Lachaevu for constructive comments, after which I decided to add an article the following information:
1. The sensitivity of the device is not very high, and it is designed for a direct hit by light from the master flash on the photodiode. To prevent false positives is rather positive, than negative. The vast majority (if not taken special measures) proposed Slave will not work on the reflected light. Structurally, it makes sense to collect it in a separate building, connected to the outbreak of two-wire cable of sufficient length. This will randomly oriented in space flash and light-sensitive element (photodiode). For example, a flash, mounted on a tripod, can be directed to the object at a time as Slave, mounted on a tripod leg, will be directed toward the triggering flash.
2. This scheme works confidently in the light flashing fluorescent lamps. This allows you to use it not only in home location, but also in offices, schools, kindergarten, etc.