Here is a photo of the arena on cloudy day a few weeks ago.
Here is a sunny day. One of the nice things about this arena is that large window with so much natural light coming in.
Horses are highly vigilant. They are aware of even the smallest changes in their surroundings. This is how they have survived for millennia. When I am riding Biasini in this nice bright arena I am usually thinking about how he is going and what we are working on. But sometimes an important change may have taken place in the few seconds it takes to go around the arena. Let’s say it was cloudy when we were up at the A end of the arena under the big window. But then the sun comes out and by the time we get back to A. There has been a big change. Look!
For Biasini the patterns of sunlight can be alarming. They were NOT there the last time he passed by. Is this something dangerous? What is it? I know it is just the sunlight but he does not know that. To him there is now something on the floor of the arena. He may balk or slow down or try to spin round and go away from it. But if it is a sunny day as in the second photo then he will have seen those patterns the whole time he is in the arena and not be concerned. It is a concern to him if they appear and disappear. I know that he will put his head up but if I speak to him and give his withers a rub he will bravely carry on.
This is my response to this week’s Lens Artists Photo Challenge Natural Light. Amy is the Lens Artist who chose this challenge and there have been some amazing responses to it so do click on the link and see some of the responses in the links and pingbacks in Amy’s comments.
HorseAddict 
I’d love to hear from you!