Rencently I had a client that wanted his 21' flagpole lit with low volage lighting (currently lit with a line voltage flood). I was thinking of putting 2-50mr16/10 degree towards it. At 20' with 1 mr16 50w I would have 27 footcandles/beam spread of 3.5'. Is there anything that recommends what something should be lit to (footcandles) or is it a trial and error issue. I'm not sure flag dimensions but i'm sure 3.5' spread should cover it.