Originally posted by mcgregni The satisfaction gained of using old skool TTL may well be worth the effort though !
The real limitations / hazards of using the extension cords in a studio situation is going to be the length of them (too short probably) plus the whole tripping over them / everything coming crashing down scenario .....we don’t want your next thread title to be something like “Help! Spare parts needed for multiple AF500FTZ flashes and 645N camera”
From the AF500FTZ manual I found online it looks like the Contrast Control Sync mode is limited to single slave plus pop-up flash setups ..... in that situation the pop-up will provide 1/2 the output than the slave does. Check the settings on your flashes when you activate the Contrast Contrast Sync mode, but it doesn’t look like there is a ratio setting for a split between slaves, like on the later P-TTL models.
It seems likely then that all of your flashes connected by cords in TTL mode will be emitting the same output, so it may be difficult to achieve very precise balancing. But as Clackers said, you can use Manual flash mode anyway. In that configuration you might find it more convenient to use a simple manual flash on the hot shoe as an optical trigger, at low power, and operate the AF500FTZs as “dumb” optical slaves.
And at least that way you’re not contaminating the purity of your legacy Pentax arsenal with some cheap plasticky radio devices!
[LOL; here comes the historically authentic spaghetti studio]
With the AF-500FTZ in optical slave mode, the power output can be adjusted to 1/32. As might be expected, in TTL mode it cannot be adjusted. Beam width (zoom) seems to be adjustable in both modes. However, in either case one will likely be making choices of flash distance, flash diffusion technique, bounce vs. direct, spatial orientation, blocking, etc., measuring and modifying until the intended configuration is set and the power ratios measured at the object to be photographed (target) are as desired. These setup tests would all be done in slave mode at full power. At this point, an appropriate aperture setting could be established and an exposure taken.
Next, switching to photos with TTL, the lighting ratios should be retained within the consistency of the flashes' lamp discharge function. And with TTL, given sufficient flash power in all flashes, aperture selection is less restricted -- allowing lower f/nos for more bokeh, say.
In any case, I need the wiring connection parts before I can definitively comment on relative merit of alternative approaches.