Photo and Video Terms You Should Know

Why the vocabulary

When a teammate says "bump the ISO and open up to f/2.8," you shouldn't have to guess. This is your plain-English glossary so you can read any camera menu and follow any tutorial.

The exposure triangle

Three settings control how bright your image is. Change one and you usually compensate with another.

• Aperture is the size of the lens opening, measured in f-stops. A smaller f-number means a wider opening: f/2.8 lets in a lot of light, f/16 lets in little. Aperture also drives depth of field (below).
• Shutter speed is how long the sensor is exposed, written as a fraction of a second. 1/1000s freezes motion (a robot ripping across the field); 1/30s lets motion blur.
• ISO is the sensor's sensitivity. ISO 100 is clean for bright light; ISO 3200 brightens a dim gym but adds grainy noise. Raise ISO only after you've run out of aperture and shutter room.

Real FRC scenario: competition gyms are darker than they look. To freeze fast robot action you need a fast shutter (say 1/500s), which usually forces a wide aperture (f/2.8) and a higher ISO (1600) to keep the shot bright.

Depth of field and bokeh

Depth of field is how much of the scene is in sharp focus front to back.

• Shallow depth of field (wide aperture, f/1.8) keeps your subject sharp while the background melts to a soft blur. Perfect for isolating one driver from a busy pit.
• Deep depth of field (narrow aperture, f/11) keeps both the robot and the field behind it sharp.

Bokeh is the look of that out-of-focus blur. Fast lenses produce smoother, rounder bokeh.

White balance

White balance tells the camera what counts as white under the current lighting. Gym fluorescents push footage green or orange; set white balance and your team colors render accurately.

Video terms

• Frame rate (fps): frames captured per second. 24 fps looks cinematic, 30 fps is standard, 60 fps is smooth and gives you room for slow motion when you slow it down later.
• Resolution: the pixel dimensions. 1080p = 1920x1080; 4K = 3840x2160, about four times the pixels.
• 180-degree shutter rule: set shutter speed to about double your frame rate for natural motion blur. At 24 fps that's ~1/50s (the nearest common setting to 1/48). Ignore it and fast motion looks choppy or smeared.
• B-roll: supplementary footage (a spinning wheel, hands soldering) you cut over narration or interviews to keep things visually interesting.

Using it

Every setting is a tradeoff. Want frozen action? Trade light for a fast shutter, then recover it with aperture or ISO. Want a clean portrait of your driver? Open the aperture for shallow depth of field. Knowing the terms is what lets you make those calls on purpose instead of by luck.