Sony A7 review: Mirrorless marvel?By Kevin Carter - Thursday December 05 2013 Sensor Review
As the lower pixel count of the two full-frame A series mirrorless models from the firm the Sony A7 has been somewhat overshadowed by its pricier sibling. But with a less demanding 24-Mpix sensor and on-chip phase detection AF, the A7 sounds promising for legacy glass as well as offering faster focusing with the existing E and new FE mount lenses. Read on to find out how this intriguing new model performs.
Introduced in October alongside the 36-Mpix A7R, this SLR-style mirrorless model with its 24-Mpix full-frame sensor has been eclipsed somewhat by the promise of more highly detailed files from its sibling. However, at around $600 less, the short register and the less demanding 24-Mpix sensor of the A7 sounds promising for those wishing to use legacy SLR and old rangefinder lenses with the camera.
Apart from pixel count the A7 sensor differs in one other important aspect. It has a number of pixels dedicated to phase detection AF, allowing faster autofocus than A7R with the new native full-frame FE and earlier APS-C E-mount lenses. However both A7 and A7R should be evenly matched when using firm’s A-mount SLT lenses with the new optionally available LA-EA4 mount adaptor. Although those earlier lenses were designed for phase-detection AF, the new mount adaptor has the SLT technology and PD-AF system already built-in.
Despite the differences in the sensor the A7 and A7R are otherwise very similar. It shares the same small, dust and moisture resistant magnesium alloy body and highly detailed XGA OLED viewfinder with focus peaking. Other notable features include a tiltable 3.0-inch high-resolution rear LCD, sensitivity running from ISO100-25,600 and a 5fps burst mode.
The A7 also supports both PAL and NTSC movie recording with AVCHD 1920x1080p clips at 60/50/25/24 fps. Filmmakers will also appreciate audio monitoring and the option of a ‘clean’ HDMI output for external recorders.
Removing the mirror has resulted in the A7 (and A7R) being one of the smallest, most portable full frame 35mm models available. It measures 126.9 x 94.4 x 48.2 mm and weighs 474g (16.7 oz ) without lens. The Sony A7 is shipping now at $1,699 body only, or for $1,999 with FE 28-70mm f3.5-5.6 OSS zoom.
- 24.3-Mpix Full Frame (35.8 x 23.9 mm) Exmor CMOS sensor
- Sony E-mount mirrorless body
- 1.3cm, 0.5-inch type (236M dot) OLED EVF
- 117-point phase detection plus 25-point contrast detection AF system
- 3.0-inch (921k dot) tiltable LCD
- 1080p video at 60/50/25/24 fps AVCHD
- 1/8000th second max shutter speed
- 5 fps maximum continuous shooting
- ISO 100-25,600
- Single SD/MSPro memory slot