Sony's mid-range SLT camera with translucent mirror, 16.1MP APS-C sensor, and 12fps continuous burst.
The Sony SLT-A57 was released in 2012 as a mid-tier Sony Alpha body using Single-Lens Translucent (SLT) mirror technology — a fixed pellicle mirror that passes light to the sensor without moving, unlike a conventional DSLR reflex mirror. The 16.1MP APS-C Exmor CMOS sensor. Continuous shooting at 10fps at full resolution; 12fps is available only in Speed Priority mode with a 1.4x centre crop. 1080/60fps video. In-body SteadyShot sensor-shift stabilisation. NP-FM500H battery. Approximately 618g with battery and card.
The 16.1MP APS-C Exmor CMOS sensor. SLT translucent mirror technology. 10fps continuous at full 16.1MP resolution; 12fps Speed Priority mode applies a 1.4x crop (effective ~8.4MP). 1080/60fps video (AVCHD, up to 28 Mbps). In-body SteadyShot (sensor-shift, up to 4.5 stops claimed). NP-FM500H battery. Body weight approximately 618g with battery and card. Phase-detect AF sensor above the translucent mirror.
The SLT translucent mirror provides a functional distinction from conventional DSLRs: the fixed mirror enables phase-detect AF during video recording (where a DSLR lifts its mirror and loses phase-detect) and reduces mirror slap vibration at high burst rates. The tradeoff is approximately 1/3 stop of light loss from the translucent mirror to the sensor. The 12fps Speed Priority mode applies a 1.4x crop and is not full-resolution continuous shooting.
On the used market the Sony A57 is very affordable as a vintage Sony SLT mirrorless. Condition checks: in-body SteadyShot operation, NP-FM500H battery health (shared with A65, A77, A99), phase-detect AF sensor condition, and single SD slot. Compatible with all Sony A-mount (alpha) lenses.