Glaiben's question had to do with the Flexbody, which has a lens mount that includes a mechanical shutter release for V system lenses as well as a mechanism to re-cock the lens shutter. With that setup, you connect the lens shutter to the CFVII 50c back with a cable from the lens flash sync terminal to the Flash In port: this allows the back to sense when to operate in frame capture mode, using the lens shutter to time the exposure. The CFVII 50c Flash Out port transfers the flash sync signal from the lens to an external flash system.
It will work the same way with any technical camera that provides a V lens mount, presuming that the technical camera's V lens mount has both a lens shutter release port and a lens shutter recocking mechanism.
When you're using the back in electronic shutter mode, the Flash In port acts as a remote shutter trigger and the electronic shutter does not support electronic flash triggering. So when you're using a V lens on the XV Adapter or on a technical camera fitted with barrel lenses or 35mm SLR lenses necessitating the use of electronic shutter, you do not have electronic flash triggering available.
(The XV Adapter has no lens shutter release connection, nor any way to recock the mechanical lens shutter.)
Summarizing, to your questions:
1) Yes, the Release Cord X is the wired remote release for the CFVII 50c. It works with the back when operating in e-shutter mode as well as when connected to a 907x body using XCD series lenses with their in-lens shutters.
2) This breaks into cases depending upon the configuration you are using:
- If using the 907x/CFVII 50c with XCD native lenses, you use the Release Cord X as a wired remote release. I think this also works with the 907x/CFVII 50c + XH Adapter + H system lenses, since these lenses (like the XCD lenses) have electronically timed and powered mechanical shutters controlled by the camera body.
- If using an 907x + XV Adapter—or a tech camera with any lens that does not have mechanical lens shutter capability—you use the e-shutter and do not have flash sync capability. The Release Cord X works as above.
- If using a technical camera/Hasselblad body (or other lens/shutter units) that supports C/CF mechanical shutter use, you have electronic flash capability with the CFVII 50c using the Flash In port to trigger the back from the lens shutter and the Flash Out port to trigger the flash. The Release Cord X is not used in this configuration: You trigger the exposure using the body or technical camera's shutter release.
G