Originally posted by AVANT As far as I know, there are no standards for pre-flashing, so chances are that those "channels" are proprietary. I wouldn't rule out the possibility that other wireless flash systems can trigger your flash, but the chances are minimal as well. And even if they do, that's when you're supposed to change to a different channel
Thanks, AVANT. For what it's worth -- and as you probably know -- changing channels with the Pentax system involves turning the camera off, taking the strobe off the bracket, changing the channel on the strobe, putting the strobe on the camera, turning on the camera and holding down the shutter button halfway to register the new channel, shutting things down, removing the strobe from the camera and putting it back on the bracket. Sigh. And you're doing this with a family holding a pose in front of you, just because somebody else accidentally triggered your strobe. I think it would be easier to ask the onlookers to hold off shooting for a minute or two.
But I'm convinced now this is not something I have to lose sleep about.
I just found a nice little summary of the various technological options involved in wireless flash, on Adorama's web site;
click here. After reading this article, I see that there actually ARE or at least used to be flash systems that were triggered simply by some other flash, any flash. Fortunately, the Pentax 540/K10D system is not subject to that problem, because it uses the "channels".
I think that answers all my questions pretty well.
To summarize the reasons for using cables:
- Eliminates any risk of accidental firing of the flash. I don't consider this worth much since the risk looks like it's close to zero anyway.
- Off-camera flash connected via cables can do high-speed sync. Not a big deal. I do use high-speed sync outdoors occasionally, but not often, and when I'm outdoors, I don't usually have the flash off the camera anyway.
- Cables allow remote triggering when wireless won't work because there's no directly line-of-sight between off-camera flash and camera, or when the camera's pre-flashes aren't picked up by the off-camera strobe either because it's too bright or because the distance between the flash and the camera is too great. But here again, this doesn't strike me as a big deal for me personally and the kinds of shots I'm taking.
So, wireless is looking better and better. If the camera and flash are on a bracket, well, I bought the cables so I might as well use 'em. But I will now feel more willing to take the flash off the bracket, ask somebody to hold if five feet to my left, and count on wireless to make the connection. Which will be very useful.
Thanks both to Andreas and AVANT for your helpful responses.
Will