Sunburn, too cold or other on Antelope den/phal?
 

Hi! I just got a fantastic Den. antennatum. Shortly after, one of the leaves started to discolor and I thought it was sunburn, so I moved it to more filtered, bright light, but the room is pretty cool, around 70°F.

Some photos with dollar bill for scale (6")

I'd be so very thankful for input!

Is it a top leaf or lower leaf? If a lower leaf, that's just natural aging - the older leaves do yellow and drop. If higher on the plant, then sunburn could be the culprit. (If you just got the plant, was it in a hot car for any length of time? Sun/heat damage can take just seconds...)The room temperature should be fine - that would not cause the leaf to yellow like that.

Thank you for the information, Roberta! It was the very bottom leaf on the cane. It is a great relief! I know some dendrobiums shed the leaves, but have never seen that. I got it from Seattle Orchid and it is the most perfect orchid I have ever gotten. I very most highly recommend this nursery!

Yes, that one is just "force of nature"