Olympus OM-D E-M5 Mark III vs Panasonic Lumix DC-GX9 — Which Is Better?

The Olympus OM-D E-M5 Mark III and the Panasonic Lumix DC-GX9 are both mirrorless cameras built around the Micro Four Thirds format, so any native lens moves freely between the two bodies. The Olympus arrived in 2019, a year after the 2018 Panasonic.

The Panasonic is the smaller body at 124 x 72 x 47 mm against 125 x 85 x 50 mm for the Olympus, though it is heavier at 450 g versus 414 g. The Olympus is the lighter carry, the Panasonic the slimmer fit in a tight bag.

The Olympus is the stronger camera for action. It shoots at up to 30 frames per second against 9 on the Panasonic, and its 121 autofocus points outnumber the Panasonic's 49 when tracking a moving subject. Its 1/8000 second top shutter speed versus 1/4000 also suits wide apertures in bright light.

They share a 20 MP CMOS Micro Four Thirds sensor, a 200 ISO base setting and in-body stabilisation for handheld work at slow shutter speeds. Where they differ, the Panasonic's 2,760,000-dot viewfinder shows more detail than the Olympus's 2,360,000-dot panel, and its standard ISO range reaches 25600 against 6400, though both extend to 25600 expanded.

Slow motion is where the Olympus takes the lead: its 120 fps maximum frame rate doubles the Panasonic's 60 fps, giving twice the slow-motion reach for fast action like a bird taking flight. Both cap at 4K, so the extra frames are the practical edge for movement-heavy footage.

Timelapse needs no external intervalometer, since both record timelapse in-camera. Each records in MPEG-4 and MOV, with the Panasonic adding AVCHD.

Weather sealing is the Olympus's protection edge: it is sealed against dust and moisture while the Panasonic is not, which matters for rain-soaked streets and coastal hikes. The Panasonic answers with a built-in flash for quick fill light at close range, though both support external flash units.

The rear screens are close, with a 3-inch flip-out touchscreen on both for waist-level and low-angle framing and the Panasonic resolving 1,240,000 dots against 1,040,000 on the Olympus. WiFi and Bluetooth appear on both, and neither has GPS, so neither tags photos with location data on its own.

The Olympus is rated at 310 shots per charge against 260 for the Panasonic. Both use a single SD card slot, so neither offers a backup card, but the Olympus slot supports the faster UHS-II standard, letting a fast card clear the buffer sooner after long bursts.

Both charge over USB, so a power bank works with either body.