Photography Basics: Aperture, shutter speed, and ISO as explained by a novice.
Aperture
A camera’s lens closes and opens as a photo is taken, how open it is determines how much light hits the sensor, and can affect how quickly the lens opens which also affects how much light hits the sensor. Aperture values look like f/2.8, f/4, f/5.6, f/8, f/11, f/16, etc.
f/2.8 is a small opening, meaning there is a shallow depth of field, and most of the photo will be out of focus. Think Portrait mode on the iPhone, there is one subject in focus and the other depths are out of focus.
On the other hand f/16 is a large opening, and as much as possible will be in focus, which is good for things like landscape photography. This will result in a deep or wide depth of field. In the photo below, the fence slats are in focus, but the cat as well as the far background is out of focus.
Depth of Field refers to how much of the photo is in focus, shallow depth of field correlates with a small aperture value, less of the distance is in focus.
For more about aperture from a more reputable source check out this video by Apalapse on YouTube.
Shutter Speed
Shutter speed refers to the speed at which the lens opens and closes. Faster lenses let in less light and can capture things in motion without blur. Slower shutter speed will be blurry without a tripod, and will let in more light.
A shutter speed of 1/30 would need a tripod for sharpness, and would likely be in a dark setting. Opposite that, shutter speed of 1/250 would be good for motion and a well lit scene.
In the photo below the sky is washed out because it was a nice bright day, and the car is blurry because it was moving with a slower shutter speed of 1/25
For more about shutter speed, here is a YouTube video from British Academy of Photography.
ISO
ISO is the measure of how much light is hitting your camera sensor. This shows as noise in a photograph. Noisy photos are usually taken in too dark of light with too low of ISO. Higher ISO is better for darker areas, and low ISO is good for sunny days.
In the photo below, you can clearly see the noise on the door in the background, my camera’s ISO was set to 6400 which is quite high, and it wasn’t necessary, so there is visible noise.
Watch this video from Joshua Cripps Photography on YouTube for more about ISO.
Dynamic Range
Dynamic range refers to the amount of light and dark parts to your image. Sunset landscapes are a good example, there is a large range of white or light spots, as well as a handful of black or dark areas. Having an array of light to dark on an image displays good dynamic range.
For example, in the two images here, one seems flat, as there is not a full range of light and dark areas. In the other, there is a more even array of dark to counteract the washed out sky. It still may be an uninteresting photo, but the colors don’t look quite so flat with the lack of contrast.
