Photo Terms by Sara

Exposure value, or EV, refers to the amount of light for a given exposure. It is denoted as a single number. Its value is subsequently used to calculate the correct combination of shutter speed and aperture at a given ISO speed of the sensor.

Light Meter measures how much light is being admitted into the camera. Negative numbers make a picture effectively darker and positive thus make it brighter. 

Depth of field is a measurement of how much distance is placed between the viewer and the subject being captured. Telephoto lens have a smaller depth of field and a wide-angle lens has a larger depth of field.

Diaphragm controls how much light enters the camera by determining the size of the opening call the aperture. The diaphragm functionally controls how much light can enter through the aperture. When taking a picture in a bright area, you should make the diaphragm smaller because that effectively makes the aperture larger and lets in a smaller amount of light, keeping the photo from coming out overexposed.

ISO refers to the sensor’s sensitivity to light. A higher ISO should be used in dark settings and a lower ISO is effective in brightly lit settings.  

Aperture When your lens is open very wide, the background is typically out of focus. Wide-open aperture is good for portrait photographs, when you don't want the background to interfere with your subject. When your lens is only open a small amount, everything from the foreground to the background is in focus. This aperture is used for landscape photographs, so that all of the scenery in the photo is in focus.

Shutter Speed measures, in seconds or fractions of seconds, how long the shutter of a camera stays open to let light in through the aperture. A faster shutter speed will keep the shutter open for a shorter amount of time, and a slower shutter speed lets it is for longer.  This becomes functionally relevant when trying to capture some sort of fleeting condition or subject in motion.

Kelvin Degrees: all visible light has a certain temperature in Kelvin that the camera is capable of altering. The about of Kelvin Degrees of the light coming from that object determines the colors that will be captured by the camera.

- Sara Coker