Sony a7 IV vs Sony a9 III — Which Is Better?

The Sony a7 IV (2021) and the Sony a9 III (2024) are both full-frame mirrorless cameras on the Sony E mount, so your lenses work on either body. Three years separate them, and the gap shows in speed, not mount or format. The a7 IV measures 131 x 96 x 80 mm and weighs 659 g, while the a9 III is taller and slightly heavier at 99 x 133 x 83 mm and 700 g.

The Sony a7 IV is the stronger choice when detail matters most, pairing a 33 MP sensor with more room to crop a distant animal or extract a tight composition. The a9 III offers 24.6 MP, so its files carry fewer pixels for heavy cropping or large prints.

The a9 III is the clear choice for split-second action, shooting at 120 fps against 10 fps with a 1/80000 second shutter that freezes a golf swing or a bird taking off. The a7 IV answers with a wider native ISO range, 100 to 51200 against 250 to 25600. Both share 759 autofocus points, in-body stabilisation and the Bionz XR processor. The a9 III's viewfinder is far sharper, at 9,437,184 dots against 3,686,400.

For slowing fast action in 4K, both cameras offer the same ceiling, recording up to 4K with a maximum frame rate of 120 fps, so neither gains resolution headroom or slow-motion depth.

One convenience gap matters to time-lapse shooters: the a7 IV has built-in interval recording, while the a9 III does not. If you shoot rolling clouds or construction sequences in camera, the a7 IV saves the external intervalometer.

The a9 III gives you a noticeably better screen for checking focus and colour on location. Its 3.2-inch TFT LCD carries 2,095,104 dots, more than double the a7 IV's 1,040,000 dots on a 3-inch LCD.

Practical controls and protection are shared specifications. Both have weather sealing, a fully articulating touch screen, and Wi-Fi plus Bluetooth for remote control and image transfer. Both rely on external flash units rather than a built-in flash, and neither has GPS for automatic location tagging.

The a7 IV holds a small edge in rated battery life, with 580 shots against 530 for the a9 III. Both use the same NP-FZ100 battery and both support USB charging, so one set of spares and cables covers either camera.

Dual card slots on both let you separate stills from video or keep writing when one card fills mid-shoot. The a7 IV takes SD (UHS-II compatible) and CFexpress Type A cards, while the a9 III takes SD and CFexpress media.