Originally posted by jqjones Hi jqjones,
Either of these that you linked to should give you full P-TTL compatibility, if the mfg's claims are correct. The second link is to a cord that claims to be fully compatible with all the digital systems that use the most standard basic hotshoe clamp (all except the proprietary Minolta/Sony hotshoe). The extra contact pins in the second one are supposed to accommodate all the different contact positioning of the different brands and "intelligently" choose the appropriate combination for each specific brand. They probably call it TTL to avoid confusion (different mfgs call their digital preflash TTL flash systems by different names ie: I-TTL, E-TTL, P-TTL). Pentax TTL (pre-digital, with no preflash) hotshoe cords have 4 conductors, while P-TTL cords have 5)
Either should work with your proposed purpose since any P-TTL cord will also be compatible with manual only flashes, but you could probably save some money by looking for a used old-style hotshoe to hotshoe flash cord, with just a single contact in the middle (the ground contact is in the frame of the shoe that you slide the base of your flash into). This center contact transmits the signal to fire the flash. The other contacts are used to communicate with the camera for things like aperture, metering, AF assist light, etc, and are not needed if you're using manual settings. These are usually considerably lighter and smaller than the P-TTL cords which require 5 conductor wires.
Another setup that would possibly give you more flexibility (lengthwise) is to find a single contact hotshoe to PC cord adapter to mount on the camera and a PC to hotshoe adapter to fit on the remote flash. Then get PC cords of different lengths for different applications. These will require manual control of the flash.
Pentax also makes P-TTL compatible cord components. The "FG" Hotshoe Adapter slips into the camera's hotshoe and adapts the hotshoe contacts to either of the Pentax 5P cords (3' coiled or 9' straight) which then connects to the "F" Hotshoe Off-Camera Adapter that has a 1/4-20 threaded hole in the bottom and a hotshoe for the remote flash on top. To make things more complicated, they also offer an "F" Hotshoe Adapter that slides into the camera's hotshoe, has a port for the 5P cord, and has an additional hotshoe on top to allow mounting a P-TTL flash on the camera as well as providing for wired remote P-TTL flash. These components are considerably lighter and smaller than the third party assemblies I've seen, and are pricey new, but can be gotten fairly reasonably used if you can find them.
Scott