First, we focused on aperture, also known as f-stop. For those not camera-savvy, this means how wide the hole (aperture) that lets light in to the camera is. Wide apertures have smaller f numbers (my Nikon D5100 goes down to f3.5), and narrow apertures have larger f numbers (f36 for me). As you can see from the above photo, wider apertures also result in a blurring of anything outside of the focal point. This is called depth of field.
Next, we talked about exposure. This means how light or dark your photo ends up looking, and is controlled by many variables, including aperture, shutter speed, and ISO. The above photo shows a normal exposure. Personally, I prefer a little more shadow.
Okay, maybe not that much. This is called underexposure. Francisco Goya would be proud.
Conversely, it is also possible to get an overexposure, in which too much light reaches the lens. Look out, Thomas Kinkade!
Finally, we discussed metering. This is a tricky element to work with, since we cannot just turn a dial on our cameras to adjust for it. At least, not that we have yet learned. Metering is what happens when your camera takes all of the values in your scene and averages them out to give you what it “thinks” is the correct balance of light and dark. As in the above photo, it works well when there are many different values in your scene.
Admittedly, this was a poor choice of subject to show a difference in metering. However, I think it is still possible to see that the bottle is darker by itself than set against a backdrop. Had I taken a photo of a white or black item, the difference would be much more striking.
Finally, the obligatory selfie. I was just practicing focusing on eyes, Perry!