Consolidating Sony’s entry-level SLT line-up, the Alpha 58 replaces both the Alpha 37 and Alpha 57. Phil Hall finds out how successful the merger has been. Read the Sony Alpha 58 review...
Sony Alpha 58 at a glance:
- 20.1-million-pixel, Exmor APS HD CMOS sensor
- 1.44-million-dot OLED electronic viewfinder
- Sony Alpha mount
- Sensor-shift stabilisation
- Tiltable 2.7in, 460,800-dot TFT screen
- Up to 8fps shooting rate
- 1080p HD video capture
- Street price around £430 with 18-55mm f/3.5-5.6 kit lens
Sony Alpha 58 review – Introduction
Like all Sony DSLR-style cameras we have seen since the launch of the Alpha 33 and 55 in 2010, the Alpha 58 is based around the company’s translucent mirror technology, in which the moving mirror and pentaprism found in a typical DSLR are removed and replaced with a fixed, semi-transparent mirror. With roughly two-thirds of the light that comes through the lens travelling on through the translucent mirror to the sensor, the other third is bounced up to the AF sensor. The benefit of this is that autofocus can remain in action even when a shot is fired – on a traditional DSLR, the mirror is raised and AF is interrupted very briefly when the shutter is triggered – while the burst frame rate can also be improved over DSLR rivals. The absence of a pentaprism does, however, see the optical viewfinder substituted for an electronic equivalent.
The Sony Alpha 58 features a completely new 20.1-million-pixel sensor, but with some established leaders in this sector, does Sony’s new model offer the photographer enough to stand out from the crowd?
Sony Alpha 58 review – Features
Rather than opt for the 24.3-million-pixel sensor found on Sony’s higher-end SLT cameras, Sony has developed an all-new, 20.1-million-pixel Exmor APS HD CMOS sensor that improves on the 16.1-million-pixel Exmor APS HD CMOS sensor used by both the Alpha 37 and 57. There is also a new and improved Bionz image-processing engine that individually adjusts levels of noise reduction and sharpness in different imaging areas, while the ISO sensitivity is good for a camera in this class at 100-16,000.
The electronic viewfinder is a 1.44-million-dot OLED device with Tru-Finder technology. This improves on the LCD display found in the Alpha 57, reducing overall power consumption, while the 100% field of view offered is better than most DSLRs at this price point.
Interestingly, the rear screen has shrunk in size since the Alpha 57, with a 2.7in, 460,800-dot display now in place compared to the 3in, 921,000-dot screen on the previous camera. The screen can be pulled out and angled for shooting at different heights, but because its hinged differently to that on the Alpha 57, it doesn’t offer quite the same breadth of movement.
The AF system builds on the system used in the Alpha 57. The 15-point AF arrangement, of which three are the more sensitive cross-types, is in place in the Alpha 58, which also benefits from a new lock-on autofocus technology for what is claimed to be speedier, more accurate subject tracking.
As mentioned, one of the main advantages of Sony’s SLT technology is the ability to shoot a faster frame rates compared to rivals, so its no surprise to find that the Sony Alpha 58 is capable of shooting at up to 8fps. This is a little deceptive, however, with 8fps only possible using the camera’s dedicated Tele-zoom Continuous Advance Priority AE mode. This sees the image cropped by 2x (with the centre of the EVF view automatically magnified), the resolution dropping to a lowly 4.9 million pixels, and the restriction of being able to shoot JPEGs only. Not only is this slower than the all-out pace of the Alpha 57, which could shoot at up to 12fps in Tele-zoom Continuous Advance Priority AE mode, the Alpha 57 is also, more tellingly, capable of shooting at 10fps at full resolution compared to 5fps for the Alpha 58.
Auto Object Framing technology is included in the Sony Alpha 58, which builds upon the Auto Portrait Framing feature first introduced in the Alpha 57. Set to this mode, Sony claims that the Alpha 58 will consider what is in the scene – including people, and close-up and moving subjects – before tracking, framing and cropping the shot for ‘powerful, professionally framed compositions’. Any cropped images are automatically boosted back to the camera’s native resolution using Sony’s By Pixel Super Resolution technology, with both the original and recomposed files saved.