I’ve gotten suggestions on this from the iPhone community.
• Keep a wide brim hat handy
• Keep a black scarf or fabric to drape over your head and phone
• Don’t take photos during that time of day.

So while you’re doing all this calculating, your subject flies away?

Beautiful! When you post photos here do you have to have them available to download? (Someday I could take a photo worth stealing!)

I took advantage of a local solar program and all the equipment was free. I pay a small monthly fee to the solar company plus the metered usage. I am saving the equivalent of a peak month prior to solar!