The Leica SL3-S is a mirrorless system camera with a body measuring 141.2 x 108 x 82.7 mm and weighing 768 g, built to operate in temperatures ranging from -10°C to 40°C thanks to its weather-sealed construction. It features a 3.2″ touchscreen with a resolution of 2333k dots and a flip-out design, complemented by an electronic viewfinder offering 100% coverage. The camera does not include a tilting viewfinder or a built-in flash, but it does provide a hot shoe for attaching external flash units. With a total volume of approximately 1261 cm³, it accommodates a well-rounded physical footprint for a full-featured mirrorless body.
The SL3-S is built around a full-frame back-illuminated stacked CMOS sensor resolving 25.3 MP, paired with the Leica L lens mount and covering 779 phase-detection autofocus points that support AF tracking, touch autofocus, and manual focus. Maximum ISO reaches 200,000, and the camera offers full manual control over shutter speed, ISO, exposure, and white balance, along with a two-stage shutter and serial burst shooting mode. The mechanical shutter tops out at 1/8000 s while the electronic shutter extends to 1/16000 s, with a flash sync speed of 1/200 s and a maximum long exposure of 30 s. In-body sensor-shift stabilization is rated at 5 stops CIPA and can be combined with compatible lens-based stabilization for an enhanced effect, with continuous mechanical shooting available at up to 7 fps.
The SL3-S records video at up to 3968 pixels wide and 30 fps with a maximum bitrate of 800 Mbps, and supports a 24p cinema mode as well as slow-motion video recording. Autofocus during video is handled through phase-detection with continuous AF active throughout recording. For audio, the camera includes a built-in stereo microphone array with two microphones, a 3.5 mm jack for headset monitoring, and a dedicated external microphone input for more controlled sound capture.
The SL3-S uses a removable and rechargeable 2200 mAh battery with a CIPA-rated life of 315 shots per charge. A battery level indicator is built in, allowing the remaining charge to be monitored directly from the camera during use.
The SL3-S offers a broad set of connectivity and storage features, including Wi-Fi 5 (802.11ac) and Wi-Fi 4 (802.11n) alongside Bluetooth 5 for wireless communication and smartphone remote control. Wired connections are handled through a USB Type-C port and an HDMI 2.1 output, while dual card slots and an external memory slot provide flexible storage options. The camera shoots RAW files and supports external memory expansion, but does not include NFC, GPS, pixel shift shooting, or an advanced hot shoe.
The SL3-S includes a USB 3.2 interface for data transfer and connectivity.