The Fujifilm X20 and Remote Flash Triggering

Here's something I just discovered: The X20's popup flash will trigger optical slaves very nicely! Now, acting as the master in an optical triggering arrangement isn't very special, but the X20 does so very elegantly which is.

I'm embarrassed that I just now figured it out, since it's actually in the manual. The manual that I read cover to cover. In my defense, that section is worded pretty awkwardly (as is most of the manual). The light didn't go on in my head until I happened to re-read that section today.

Here's the scoop: By simply turning on the "External Flash" option in the Shooting menu, then popping up the built-in flash, the X20 is ready to trigger an off-camera flash, assuming said flash supports optical slaving. The remote flash has to be in manual mode; TTL won't work. If you're like me, you'll also want to set the camera itself to manual exposure and manual ISO modes so that it isn't making unwanted exposure compensations. Any compensation made by the camera will be off the mark since the camera has no clue what the remote flash power is. When the "External Flash" option is turned on, the X20 will suppress its usual TTL pre-flashes and pop a single, minimum-power flash of light to trigger slaves. My initial experiments indicate that the light from the pop-up flash will have almost no effect on the exposure unless you're really close to your subject (I was just testing it at about 2.5 feet and it was negligible).

A couple thoughts I'm having about this.

First, since the X20 has a leaf shutter and there's no RF trigger circuitry lag to contend with, this triggering method is good for shutter speeds way faster than the typical 1/200 or 1/250 sync speed of a DSLR. In my experiments it worked great up to 1/1000. According to the Strobist site, the leaf shutter on the X100S cannot go faster than 1/1000 when the lens is at f/2 (wide open on the X100S). Apparently there's some sort of physical limitation with the shutter that will cause edges to get less exposure (sort of like vignetting) when the shutter is faster than 1/1000 and the lens is wide open, so Fujifilm just doesn't allow you to do it. I would expect a similar limitation on the X20. To get faster shutter speeds (and faster flash sync speeds), you have to stop down the aperture which works against one of the primary reasons you would want ultra-fast flash sync speeds - to enable you to open the aperture in order to maximize depth of field in bright, sunny conditions. On top of that, full power on a flash is usually around 1/1000 second in duration, so faster shutter speeds than that won't be able to use the full power of the flash (which might not be an issue). All things said, even the worst case of 1/1000 is really screamin' if you're used to DSLR sync speeds!

Second, an X20, a speedlight, and a small modifier, makes for an incredibly small and nimble portrait kit! I'm thinking my LumiQuest Softbox III is absolutely ideal for this. I've got a business trip coming up that may be the perfect opportunity to test it out.

My next task: To take a good portrait with this kit to prove that big power can come in small packages. So far, all I've done is practice shots to learn the ins and outs of it.