Fotoartist wrote:
Does trigger voltage matter if the flash is on your hot shoe and used on manual?
Excessive trigger voltage can harm the camera in that the current goes through the synchronization mechanism within the shutter- that mechanism acts as a "switch". The voltage emanates from the trigger circuity of the flash unit and remains at the same level regardless of the mode- manual, TTL, or auction flash and also regardless of the power output setting of the flash unit. The same problem can occur whether the unit is attached to the hot shoe or wired to the came via a synch cord.
Each camera manufacturer specifies a maximum allowable trigger voltage for its products. Some manufacturers specify as much as 250 DC Volts and others as low a 5, 7, or 10 DC Volts.
Most currently manufactured speed lights, mono-lights, and power pack operated studio type units feature solid-state trigger circuits which enable low trigger voltages.
Some folks may think theses cautionary notes are old wive's tales, myths, urban legends and paranoia, however, this kind of damage can occur with mismatched equipment. So...whenever I see a question about older flash gear, brands or models that I have no experience with or knowledge of their electronic specifications, I issue these precautionary warnings.
The good folks at Wein and Paramount Cords make and sell Safe-Synch adapters that reduce excessive trigger voltages to safe levels so that just about any OLD flash can be used with modern digital cameras.
There are a few older speedlights made by Vivitar and some other studio type lighting gear that was extremely well made and thereby survived to this day but harbor outrageously high trigger voltage that can mess up a camera something awful and even deliver a nasty shock to the photographer of the synch cord polarity is reversed. The arc-over from the high current was known to even carbonize or burn out the synch contacts of old film cameras.
This is some mythology though! If overvolted, the camera will no explode, burn up, emit smoke or melt. It' just that all those tiny little chips, microcircuits, marvelous little semiconductors, when assaulted by a voltage spike will quietly pass away without so much as a last breath.
This does not necessarily apply to triggering any flash unit via radio or IR, however, I am not sure if high trigger voltages can or can not harm a remote receiver. I use Pocket Wizards and have used them successfully with old flash gear with high trigger voltages with no adverse effects. I am not sure about other brands. Photoelectric cells are not affected.