Quote Originally Posted by polyglot View Post
r.

A common configuration is sun for "normal" exposure and flash at -1 for fill. Say you're shooting ISO100, a likely combination would be f/11 1/200s exposure (sunny-16 light) and the flash with enough power to illuminate f/8, i.e. one stop less than what your aperture is actually set to. If you wanted the flash and sun to be equal, obviously you'd set the flash power to f/11 but it's going to look bright & flat and if you're shooting chromes then you'll actually be a stop overexposed on any part of the scene that is lit by both sun and flash. If you want more DOF (smaller aperture) with the same lighting balance, you need both a longer exposure and more flash power.

Aperture affects both flash and ambient, shutter affects only ambient. Flash/subject distance also affects flash power via the inverse square law, so a little bit of moving stuff around can go a long way.
This is quick and easy. No fiddling around and it works the majority of the time. If you try it you may not bother with the other methods. But if you're trying to work in a set piece situation you WILL need to work a more accurate method.
I believe the Pentax 67 has a sync speed of 1/30 of a second so any comment regarding ignoring shutter speed should be taken with a grain(or two) of salt. Using a higher shutter speed will fire the flash before the shutter opens.
Unless you're using one of their leaf shutter lenses.