Maximum footcandles?

[Royal]

Cold temps are here, and the OB has really helped my collection explode! So instead of windowsills this winter, I set up a borrowed HID light. It's a 400w HPS and really puts out some light. I think the neighbors are starting to wonder.

My question is how much is too much light? I grow mostly high light Cat alliance orchids, but my new (cheap) light meter is reading 4,500 - 6,000 fc's depending on plant height. Is this going to cause me problems? Thanks in advance,