Lol ! I guess I had incorrectly assumed that wouldn't give me diffuse light but if all the background terrain is out of focus then of course it will be diffuse. Then I also thought it wouldn't necessarily be at the right colour temperature because unless it was pointing straight up it would pass light reflecting from the surrounding terrain. OK so perhaps if I find a window with a view of a landscape plus blue sky with some puffy clouds thrown in for good measure it should be perfect.