The photo course continues! Ha. I finally figured out how to look at the photo info in iPhoto (news flash: you don’t have to sit there and write down your settings and remember which settings correspond to which photo because iPhoto tells you all that if you know where to look).

On to the lesson (download here).

It starts with ISO, which is the film speed. The takeaway is that a higher ISO (800-1600) means the photo is captured on film or the digital sensor quickly, and you’ll need less light. This is good for indoor and other low-light situations. A lower ISO (100-200) means that the photo is captured more slowly and you’ll need more light. This is good for outdoor bright light situations. The tradeoff is that a higher ISO means more “noise” in the photos (they’ll be more grainy). So you can’t always just adjust the ISO higher to compensate for low light, unless you want a grainy photo.

Shutter speed is pretty self-explanatory; it’s how quickly the shutter operates. A fast shutter speed will freeze action, while a slow one will blur it. The lesson contains handy rules of thumb for each range of shutter speed. For example, anything slower than 1/50th of a second probably requires a tripod so that only the moving object will be blurred.

The exercise was to take a photo of some water flowing over an object. I worked in Shutter Priority (Tv) mode so that was the only setting I had to worry about. The first lesson I learned is that it requires a LOT of light to take photos using a high shutter speed. I tried doing the exercise at the kitchen sink and then outside in the shade, but when I tried to shoot at 1/1000th of a second, the photo was too dark. So the only way I was really able to complete the exercise was to go outside in bright, direct sunlight.

Here are my photos, beginning with the slowest shutter speed. Notice how they go from showing motion to “freezing” the action.

Shutter: 1/80; Aperture: f/16.0; ISO: 200

Shutter speed: 1/1000; Aperture: f/5.6; ISO: 320

Shutter speed: 1/2500; Aperture: 5.6; ISO: 800

Shutter speed: 1/4000; Aperture: 5.6; ISO: 800

1/4000 is getting super fast, and you’ll notice that the camera is at its limit trying to compensate with the other settings, and the photo ends up a tad underexposed.

Just for fun, I took a super slow one:

Shutter speed: 1/10; Aperture: 32.0; ISO: 100

Again, the other settings are trying to compensate for how long the shutter is staying open (the aperture is high and the ISO is low). When I tried to go slower than 1/10, the photos started getting really overexposed.

It helps to zoom in and notice all the details and just how many water droplets are frozen the higher the shutter speed.