This video glossary covers the terminology and defines the meaning of common video terms related to cameras, codecs, lighting, film set lingo, post-production workflows, and everything else you ever wanted to know about film and video production.
Data rate refers to the amount of information being captured to a memory card per second. As it tends to go, having a higher data rate means your image will be captured and recorded in a higher quality. That’s why higher resolution cameras, like those that shoot 4K and beyond, will require memory cards with higher data rates to record all the image’s information correctly. For more about Data rate and memory cards, check out our ultimate guide to memory cards.
The depth of field of a particular shot refers to your camera’s area of focus and is usually referred to in the form of deep or shallow depth of field. Shallow depth of field refers to only a small part of your frame actually being in focus while the rest of the frame is out of focus. A deep depth of field refers to a larger portion of your image being in focus and is particularly useful when showing things that are close up and far away at the same time. When you rack focus, you are changing the area of the screen that’s in focus, thus changing the depth of field.
Diegetic sound (or music) is sound that originates from within the narrative of the film. If a gangster fires a gun, the sound of that gun is a diegetic sound (also if the sound is a sound effect, which is added in post-production).
The point is, that the sound of the gun originates from within the film narrative. Likewise, it is considered diegetic music when the pianist Sam plays the tune ‘As Time Goes By” at the bar in the movie Casablanca. For more about diegetic and non-diegetic music and sound, check out our deep dive on it here.
Diffusion refers to a type of material that diffuses light as it comes from a source and reaches a subject. Diffusion can help to soften a harsh source or decrease strong shadows that might be caused by the angle of light or cast by grip equipment that’s in the way. In this way, diffusion helps cinematographers control and shape light to be softer and create fewer shadows.
Digital zooms are zooms that get added in post, usually by cropping in from a higher resolution to a lower resolution without changing the actual aspect ratio itself. This creates the illusion of zooming in without needing a lens change.
Dollys are a wheeled film tool that runs along a dolly track for the purpose of recording smooth movements without any bumps or hiccups.
When you create a shot using a dolly (or a similar style of tracking movement) this can be called a dolly shot and is a popular device in a lot of shows and movies.
However, not all tracking shots use actual dollys - nowadays, Steadicams and gimbals can help create smooth movement without the need to lay down any actual track.
Standing for Digital Single Lens Reflex, DSLR refers to mid-level digital cameras like the Canon 60D and similar mirrored cameras. The mirror refers to how the DSLR cameras reflect light from the lens to a viewfinder, or directly to the image sensor when you are recording.
A camera’s dynamic range refers to the spectrum between the darkest part and the lightest part of an image that the camera can pick up. In this instance, “pick up” refers to what a camera can capture without losing the detail and definition of what’s being captured. So for example, a camera with a high dynamic range would be able to capture a lot more visual information in a dark room or a really blown out daylight exterior than a camera with a lower dynamic range. In the case of lower dynamic range, you would lose more image quality, resulting in the shadowy part becoming a detail-less mass of black, or an extremely bright image to a large white mass - which is why you want a camera with a high dynamic range!
Grant Harvey is a freelance writer, screenwriter, and filmmaker based out of Los Angeles. When he’s not working on his own feature-length screenplays and television pilots, Grant uses his passion and experience in film and videography to help others learn the tools, strategies, and equipment needed to create high-quality videos as a filmmaker of any skill level.
About the author:
Jan Sørup is a videographer and photographer from Denmark. He owns filmdaft.com and the Danish company Apertura, which produces video content for big companies in Denmark and Scandinavia. Jan has a background in music, has drawn webcomics, and is a former lecturer at the University of Copenhagen.