Although I've read a good deal about ISO, shutter speed, and aperture (even whole books on one of the subjects), I've never read a better explanation of ISO than Darcy has on today's 31 Days to a Better Photo series. She asked us to take the same photo starting at our lowest ISO and then doubling it while we watched the shutter speed. It's a very rainy, cold day here, so I opted to take an indoor shot of the vintage Kodak Brownie I picked up a week ago. All the shots were taken at 2.0 aperture with my 50 mm lens. As expected with every increase in ISO there's a corresponding increase in shutter speed.
ISO 100, Shutter speed 1/10
ISO 200, Shutter speed 120
ISO 400, Shutter speed 1/40
ISO 800, Shutter speed 1/60 (Inside on a gray day, this is the ISO I typically have to use if I want to hand hold my camera, which I did today.)
ISO 1600, Shutter speed 1/100 (With this ISO you typically see a lot of noise, although I don't seem to be able to distinguish much on the computer. If I were to print this series, it might be much more noticeable.)
I'm enjoying these exercises even though I've done similar ones in the past for online courses. Every time I do a series of these, I understand the concepts better.
