HELP--Newbie Cattleya owner in need of assistance!

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It's most likely a burn and the edges where you cut are just dying back a bit. Feel the leaves when they have been under the light for a while and see if they feel warm or hot. If they do, it is too much light. It may even adjust eventually to that much, but it would need a slow introduction. Moving air also helps keep it a bit cooler. Keep an eye on the wound, but I expect it won't go much further as far as the black edges are concerned. The rest of the leaves look healthy to me.