K25 is where my flash usage comes from Dave. IMO, still the best there has ever been in film. K64 I didn't like the greens for some reason

so flash and K25 became the std. I never go over ISO 50. I've tried 100 but I always go back to 50. Sometimes I use just the pop up flash with a white card held out in front of it, bent so as the direct light downward. So in reality, its bounced flash. Other times I'll use twin flash units fired with slaves from the inbuilt flash. Harsh lighting, yes sometimes for real mate. Other times it seem to work well.
Mark Plonsky has an excellent twin flash setup that worked superbly with the Canon "G" series. I think hes now using a macrolite with his DSLR.
Anyway, DOF or lack of it is just something we get used to I guess. Well for me anyway.
All the best in the UK Dave.
Danny.
Worry about the image that comes out of the box, rather than the box itself.