Beginning with ISO

If there is an abundance of light, my choice will likely be to change the aperture/shutter speed combination. If light levels are low, my choices may become limited because I’m working either at the widest aperture provided by the lens or at shutter speeds that are too slow, particularly if I don’t have the benefit of a tripod.

So, when I walk out the door to begin a day of shooting, I evaluate the quality of the light outside my doorstep. If I’m shooting on a bright sunny day, I set my ISO to 100 or 200. If it’s a cloudy day, I set my ISO to 400. If I walk indoors into a home or a restaurant, I increase my ISO to 800, 1600, or even higher. I do all this well before I’ve even found the first image I intend to take.