Technology glossary

Global shutter

An electronic shutter type that exposes and reads every pixel on the sensor at the same time, removing the skew caused by row-by-row readout in fast motion.

Most camera sensors use a rolling shutter: rows are read in sequence from top to bottom. If the subject or camera moves during readout, a spinning propeller can look bent and upright poles tilted, and bands can appear under artificial light.

With a global shutter every pixel is exposed and read at once. Sony says this lets the α9 III sensor shoot at about 120 fps without distortion or blackout and sync flash at every shutter speed up to 1/80,000 s.

The design can have a cost: the α9 III has a base ISO of 250. Independent testing reports that this comes from the extra per-pixel storage area reducing light capacity, which raises noise at high ISO.

Devices using this technology

Cameras · 2023

Sony α9 III (ILCE-9M3)

The α9 III, announced by Sony in November 2023, is the first full-frame camera with a global shutter sensor. Its 24.6MP stacked Exmor RS sensor exposes and reads every pixel at once, so fast motion is not distorted; it offers blackout-free 120 fps bursts, shutter speeds up to 1/80,000 s with flash sync across that whole range, 8 stops of in-body stabilisation and 4K 120p video. Independent testing rated autofocus and burst shooting very highly and measured image quality about a stop behind contemporary full-frame cameras because of the ISO 250 base. Owners praise its speed; noise in dark venues and the price are criticised.

Sources

  1. Sony Electronics press release: Alpha 9 III
  2. Sony Asia: ILCE-9M3 specifications
  3. DPReview: Sony a9 III in-depth review