What Is Shutter Speed?

Shutter Speed is how long the camera let light in for a single photo. For that fraction of a second the shutter stands open and the sensor - or, in older cameras, the film - collects light. It is also called exposure time, and both names describe the same thing.

Which files carry it and where the value comes from

This is exif data written by the camera at the moment of capture, so it turns up in JPEG and HEIC photos, TIFF images and raw camera files such as CR2, CR3, NEF, ARW and DNG. Phone cameras record it as faithfully as a DSLR does. Editing programs normally copy it into the file you save, so a retouched photo usually still reports the shutter speed of the original shot.

A report may show the same information under more than one name. Shutter Speed and Exposure Time are plain times in seconds. Shutter Speed Value stores the same measurement on a logarithmic scale instead, where each step up means half the time: a value of 7 there corresponds to an exposure of 1/128 of a second.

What the value looks like

The unit is seconds, and most values are fractions of one:

• 1/1000 or 1/500 - very fast, used to freeze fast moving subjects such as sport or splashing water
• 1/125 - a typical value for everyday handheld photos
• 1/15 - slow enough that moving subjects blur and camera shake starts to show
• 2 or 30 - whole seconds, for night scenes and light trails, which need a tripod

Some tools print the same figure as a decimal, so 0.004 and 1/250 are the same exposure. Photographers say a short exposure is fast and a long one is slow.

Why it matters

Shutter speed does two jobs at once. It controls how much light reaches the sensor, and it controls how movement is recorded. A fast shutter speed stops motion dead. A slow one lets anything that moves - the subject, or your own hands - smear across the frame, which can be a mistake or exactly the effect you wanted.

It never works alone. Shutter speed, aperture and ISO sensitivity together decide how bright the picture is, and there are many combinations that give the same brightness with a very different look. Reading all three rows of a report at once tells you how the photo was made: a fast shutter speed with a high ISO says the light was poor and the photographer chose sharpness over a clean image, while a long exposure at a small aperture says the camera was on something solid. That is what makes this field genuinely useful - it lets you reproduce a shot you liked, or work out why one did not come out.

The number itself reveals nothing about you. It does travel in the same exif block as the capture date, the camera model and, on many phones, GPS coordinates, so if privacy is the reason you are looking at the report, those are the rows to deal with.