Pools of light

 This is the staircase from the living room to the second floor. This style of stair rail is very common in newer houses in Chiang Mai.

 At the halfway landing, there's a window that faces south-east-ish. We have a blind mostly closed over it, but it still lets in a lot of light in the mornings. Since the living room floor tiles are quite reflective, this leads to some interesting effects...

 The oval rings are caused by sunlight reflecting off the banister on the landing, where it curves around to go up the second half of the flight. The bright bars of light on the right are coming directly from the lading window. Inside the oval, you can see the reflection of the window. 

 Looking down from the landing, a little later. You can still see the oval at the bottom, but it's gotten wider and fainter. The arcs of light on the steps are reflections off the twisted uprights.

I backed into the corner of the landing to take this photo; you can see my toes at the bottom left.