Working on lighting some big things and have discovered some odd renders when my depth mapped spotlight goes too far away from the geometry. I've tweaked the Dmap bias but just can't get it to work.. if it's too low (eg 0.0003) it looks better than none but still problems, if it's too high the gap between mesh and shadow gets too big.

Is there any solution apart from not moving the spot back too much? Also tried higher resolutions but still getting problems?

...thanks.