That's a good film/camera combination!
Mount one flash on an umbrella in a fixed location and that's your main light. Use the other one aimed at the ceiling or wall to light the room. Have a long sync cord or wireless sync hooked up to the TLR. I use monolights, mostly so I can have modeling lights and I like cords more than batteries. Your flashes should work fine. I used to have an sb800, but sold it because it was far more features than I needed and I downgraded to an sb24. Lacking cords you could probably use the sb800 as a main light and aim your sunpack up to light the room.
Then you can move around as needed and the little guy can move around within the area lit by the umbrella. Could be a pretty big area as it's won't fall off too fast with the second flash lighting the room. If you have light energy to spare, you can use a non-reflective/sheer-white umbrella to both light the subject and the room.
Here's a shot with the main light in the photo; not ideally lit, but for reference. This is with my yashica C tlr at probably f11 or so. The room lighting flash is a little weaker than the main flash as it has to cover a bigger area.
Moved camera position about 120 degrees ccw around the table so the flash is to MY right by a couple feet. in the upper left you can see the wall is a little brighter because I have the room-lighting flash just out of the left of the photo.
Something to keep the child in place is helpful for focusing/lighting too, just don't let them know you are trying to constrain them.
http://jason.philbrook.us/gallery3/v...83/DSC7609.jpg (digital photo, sheer umbrella, toys keeping the child in place)
Last edited by jp498; 05-23-2011 at 11:20 AM. Click to view previous post history.