These are all very good suggestions.
A little more about the shot conditions:
1. Canon 550D, Glidecam HD4000, Hooded monitor down low for exposure / composition / focus monitoring.
2. Enviro: Baseball field, some shots showing actors, dry manicured dirt and sky, some showing actors, green grass, trees and partial sky
3. Lenses: Mostly Tokina 11-16 fixed f2.8, some selective shots using Rokkor 58mm f1.2 for shallow DOF and one macro shot using Zeiss Jena MC Flektogon which doesn't really enter into the equation.
4. I also have one shot that I'm doing on a track dolly which should be a lot easier using an ND Grad
5. Altitude about 5230 ft, so air is pretty clear, little haze.
I've got static shots mostly under control with 4x4 filters (Schneider polarization and a .6 ND Grad)
As far as lighting control goes I own the following:
(a) Reversible fabric bounce ring (a little like a car dash reflector). It has a silver, gold, silver/gold and white fabric. I think the white diffuse fabric would be best considering all the movement.
(B) I own 1 Mole 2k, (2) 1Ks and (2) midgets. I suppose I could rent some HDMI lighting like a couple Joker Bugs ? Either way I'd be renting the generator(s). Then I have to be concerned about color correction if I use tungstens (or maybe not if I wanted to accentuate morning golden-hour effect.)
With our current schedule and field availability we would be mostly shooting in the mornings from 8am through lunch until 1pm. (Oh boy, Sun continuity monitoring :-) In the morning we would be saved from direct back sunlight as the field is at the bottom of a hill, but the overhead sky from about 30 degrees above the eastern horizon to full noon to 3:30pm is generating direct overhead light. Polarization should help a decent amount on the horizon as the sun climbs to its zenith.
Unfortunately almost all of the shots include the ground, so it would be problematic to put a fabric drop on the ground, unless it was a closeup or a ground-up POV.
I think the answer is going to be "whatever it takes" -- within budget. Additional bounce lighting, selective polarization (a little tricky on wide angle), and man-made if necessary. Probably have to do it shot-by-shot -- some much for free-form flying.
Thanks for all of your suggestions. I really value all of your experience as I garner mine. (We're doing this for the first time as you can tell. If I had even a small budget, I'd at least be using a 7D or 5DMkII. Ironically the camera cost is a relatively small % of total cost even on our shoot -- around $10 - 12k)
Oh well. Fun on a micro-budget.
Jeremy