I use only fluorescents (although my wife grows Phals on a partially shaded southern windowsill). I've got a 4-tube fixture hanging over my growing table and 3 2-tube fixtures hanging under it. Most of my Phals and Paphs are growing 12 to 15" from the lights - at around 2000 foot-candles. My few remaining Masdevallia relatives are about 24" from the lights, which works out to around 1100 foot-candles. At this point my tubes need replacement, so the levels will probably go up around 10%. BTW, I use full-spectrum daylight tubes. They put out slightly less "good" light waves than do plant lights but they leave the colors appearing natural - a real plus when it comes to flowers (and photography).
Is there any way you can get your hands on a light meter? Borrow or rent one from a photography store maybe? Orchids are very hardy plants but they're simply not going to flower well (or maybe not at all) if the light's not right.