Light-colored, textured features on phalaenopsis leaves

[cantrell]

Hi, all. I bought a couple of phals from a farmer's market a few weeks ago. One has developed a light-colored textured feature in the center of one of its leaves, and is now developing a second on another leaf.

Is this a result of getting too much sun? My phals do get a little direct sun, but it's early in the morning, and it's brief. Additionally, I have two other phals in the same spot that seem to tolerate it fine (though they've been there for much longer, and might be better adapted).

Thanks for your help.

Christian