Why Video Files Are So Much Bigger Than Everything Else

A single video can occupy more storage than years of documents and photographs combined. The reason is that video's size grows along several dimensions simultaneously.

Every second contains many complete images

A photograph is one image. A minute of video at thirty frames per second is eighteen hundred, each comparable in complexity to a photograph.

Compression exploits similarity between frames heavily, so a video is far smaller than the equivalent count of separate photographs. It is still enormous by comparison.

Any increase in duration multiplies directly. Doubling a program's length doubles its storage with no offsetting saving, which is not true of most other file types.

Resolution multiplies the per-frame cost

Pixel count grows with the square of linear resolution, so each step up the resolution ladder multiplies rather than adds.

Frame rate multiplies independently. High resolution combined with a high frame rate compounds both factors together.

Color precision and sampling add further multipliers, which is why high dynamic range footage at full color sampling is dramatically larger than ordinary material.

Production formats are far larger than delivery formats

Delivered video is compressed aggressively because it need only be decoded, not edited. Editing formats compress each frame independently for fast random access.

That independence removes the largest saving available, so an editing master can be many times the size of the delivered file for identical picture.

Camera formats designed for grading latitude are larger still, storing more precision than any delivery format expresses. That extra precision exists to be spent during grading rather than to be seen directly.

Projects multiply the total further

A finished program represents a small fraction of what was recorded. Shooting ratios in documentary and event work can be very high.

Rendered intermediates, proxy copies, cached previews and multiple export versions all accumulate alongside the original footage.

The project total is therefore several times the raw footage, and the raw footage is already several times the delivered file.

Storage economics differ from other media

Document and photograph libraries grow slowly enough that capacity increases outpace them. Video libraries grow faster than that.

Sustained transfer rate matters as much as capacity, since editing requires reading many streams simultaneously. Storage adequate in size can be inadequate in speed.

This is why video work drives storage decisions that other computing does not, and why deciding early what will not be kept is part of the workflow rather than an afterthought.