actually....as I'm new to 5 x 4 large format I'd like to run this past you....

.....the depth of field issue is what I'm trying to get in my head as the lens starts at f5.6 all the way to f64 and you see a great amount of beautiful bokeh on what I'll call 'the focusing aperture' f5.6....

my Sinar f2 has a depth of field calculator on one of the focusing knobs....I've learned how to use it....they say to focus first on the furthest point you want in focus....mark it on the ring and then focus on the nearest bit you want in focus.....this in turn lets you know you need say f16 to get the area you want in focus (superb actually....what a great way of knowing what's going to be in focus as opposed to those crappy depth of field preview buttons on DSLR's)

so, in order to get a person in focus within the scene I was thinking of say focusing on a card held behind the person by an assistant (my wife!) IF said person is not leaning against a wall or a chair or something I can focus on....and then I focus on the tip of the nose for example.....or their belly if they're fat! hahhahaha.....anyway.....so this give me say f16 depth of field needed....

so....once thats established I measure light on the face....if the ambient light gives me '15 (what I think is okay for a person to stay still at) at f16 or over then I dont need flash but if not then I'll put flash in and thus start measuring ....(by the way, remember I haven't used a meter, film etc in over 10 years!) till the flash gives me enough light to shoot at f16....

am i missing anything?