Slave flash

[oldwolf]

I have a g3 and I want to use a slave flash. I have a canon 380ex which works well on camera. But I want to also slave a Vivitar flash with a slave flash device that fires the vivitar when the main flash goes off. I cannot seem to make this work.

The slaved flash fires but not at the same second as the main flash. How do I coordinate the two?

[pturton]

If your 380ex works anything like a 420ex, there is a pre-flash which is used to determine the proper flash exposure (duration of the flash) . This pre-flash will trigger most slave units.

By hitting the '*' button prior to taking your shot you will see this pre-flash. Now wait until both flashes are ready to fire and make your exposure..

There are pre-flash sensitive slave devices available - do a search for 'pre-flash and slave' .

Adjusting the position or senitivity of the slave sensor so that it is not triiggered by re-flash but only by the full flash is another solution.

Another cause of delayed or irratic flash from a slave is the the use of older slave devices that require more trigger voltage than what some of the newer flashes have . Many old flash untis have a trigger voltage of 150 - 250 VDC and newer flash units are in the range of 3 to 25 VDC.

My Vivitar 3700 works well as a slave if I take my own advice.


Paul

[GordonSBuck]

I also have the G3 and the 380EX. I have a Sunpak "Digital Flash" slave. The "*" trick usually works very well to trigger the slave. Oddly enough, if I try to trigger the slave using the G3 internal flash, it has to be set on "1st curtain sync" to work. But the 380EX will synchonize on "2nd curtain sync" as well. It's all a matter of the timing and time delays, I suppose. You'll have to tinker a bit. Fortunately, the film cost is low.

[tsoutherwood]

I've had a lot of good results hooking up an old Helios 50 flash via
an optical slave trigger (about 10 GBP). The Helios is ancient and offers about 250V on it's trigger terminals - a bit more that the Canon will stand (!)

Anyway - I just run the camera in full manual, with the on camera flash reduced to 25% - enough to trigger the slave and give a bit of frontal fill in without any noticeable red eye. Also, ful manual prevents the pre-flash ocurring which solves the problem mentioned above. Mostly I ignore the on camera flash and either fix the aperture and use the "auto" mode on the Helios to reduce flash power (it has it's own sensor) or just do everything the old way with distance/aperture control and a set of tables.

Seems to work well - esp. as digital lends itself to running off a few test shots. I don't think I'll be needing a Canon flash anytime soon - it would be convenient, but a tad expensive...

Just my 2p's worth.

Cheers

Timbo