How bright for cattleyas
 

I want to make a secondary room for some cattleyas and I was wondering how bright should the room be? What percentage shade cloth should I have in central florida?

thanks

Cattleyas need lots of light...no lower than 2500 candles for most hybrids and can be as high as 4500 candles for species.
The light generally needs to be indirect as direct light heats the leaves which will burn them.
During the summer, in Pennsylvania, I am using 40% shade cloth over glass. That remains to be seen if it's enough. Over winter, I use 10%.
That said, I don't have my 40% up yet :shock:
My plants are looking like they have a bit too much sun (I will be putting up the new cloth this coming w/e).
Furthermore, some of the plants are throwing buds without sheaths lol. Not sure what to make of that!

Air movement is key as well if it's bright...you don't want the leaves to heat up. And even with indirect light, they can do so.

My catts are under pool screen in Ft. Lauderdale. They do well but they could probably use a little less light. I think that pool screen is only about 25% but I'm not sure. I need to introduce plants slowly because they do burn sometimes. But all my catts and vandas have acclimated to it and grow and flower well. If I had the option I would give them a little less light though.

My experience in SW Florida is that 3500Fc is about right.

Pool screen comes in two or three densities. As Tucker says most Pool screen gives about 28% shade (or 5000Fc). Shade provided by surrounding trees and buildings obviously make a huge difference as the sun moves around them, depending what time of day localized shade occurs.
I find spring is the most challenging time as light levels begin to increase. Having said all that, many of my Cattleya's get up to 5000Fc for several hours a day.

I have measured and studied light levels, but the truth is the color of leaves is the best gauge, "grass green" to "yellow/green" seems best here and produces good flowering...