the one you have with you, the saying goes. Had to run back to the office last night to pick up something and sure enough I saw the best sunset all year. My Nikon was back at the house. I did have my iPhone though. It would have to do. My son suggested last week I could get a telephoto shot with the iPhone through binoculars. Gave it a try and presto! Snapped this after sunset. Took a couple shots before the mosquitoes could get me. Used Filterstorm to sharpen and denoise.