This week's project: Learning the effect ISO has on exposure

Same subject, same lighting, same aperture (f/8) for all photos:
ss 1/640 sec ISO 800

ss 1/320 ISO 400

ss 1/125 ISO 200

ss 1/60 ISO 100

Here the pictures look pretty much the same. That's because my subject is stationary. But if you look at the shutter speed, every time you double the ISO you roughly cut in half the shutter speed. So, if you want to shoot a fast shutter speed (to freeze motion, especially in low light) you can raise the ISO. Next week I plan to try the ISO experiment on a subject in motion. Maybe I'll even try to find something besides Callie's kinetic sculpture!