July 24 2012
Sony’s upgraded SLT digital camera has a bigger battery to overcome the limited shooting capacity of its predecessor the Alpha 55. Sony extended the ISO sensitivity and upped the already impressively fast shooting rate and called it the Alpha 57.
The Sony Alpha 57 is a reasonably priced digital camera for photographers on a budget, or for those buying their first DSLR style camera.
“Today’s DSLR consumer is looking for a higher level of control and flexibility in their camera,” said Mike Kahn, director of the Alpha camera business group for Sony Electronics. “With the introduction of the new Alpha 57, we’re bringing blazing fast response rates, enhanced artistic capabilities and other advanced features to the mainstream DSLR marketplace, offering professional-grade performance at affordable prices.”
The DxOMarktests comparing the Sony Alpha 57 with similar DSLRs from Nikon and Canon confirm the upgraded model is capable of producing digital photos of similar quality, just like the older Alpha 55.
In the DxOMark lab up against two similar DLSRs, the Nikon 5100 and the Canon Rebel T3i (600D) the Sony outperformed the Canon and was not far short of the Nikon. The telling factor is the Sony Alpha 57 has slightly more digital noise in the images, particularly at high ISO settings than the Nikon D5100. This relates to the speed compromise where less noise reduction processing helps achieve the fast frame rates in a reasonably priced camera. Remember Sony makes the digital sensors for both cameras so the performance is more about the design compromises and priorities than the basic sensor design
The biggest advance in the Alpha 57 is the larger battery. Sony say the Alpha 57 should take over 500 images on a fully charged battery, while the Alpha 55 is limited to only 330 images using the viewfinder, under the same test conditions. This gives the Sony a similar shooting capacity to the Canon DSLR.
The demands on the battery are due to Sony’s Single Lens Translucent design, that uses an electronic viewfinder instead of an optical system. In a true DSLR the Reflex refers to the viewfinder using the reflection in the moveable mirror of Single Lens Reflex camera.
Doing away with the mechanical moving reflex mirror contributes to Sony to achieving the fast shooting speed of up to 12 frames per second for their Alpha 57.
Shooting Speed vs Image Quality
One consequence of the Alpha’s high frames rates is higher image noise compared to Nikon and Pentax DSLRs with similar Sony sensors. The Nikon, and particularly Pentax, DSLRS have less digital noise in the high ISO images because their cameras do more noise reduction processing. By reducing the amount of on board processing Sony saves time, helping achieve the faster shooting rates.
This is an important measure of how the cameras cope with scenes where bright light also produces dark shadow areas. The Sony have improved the dynamic range of the alpha 57 and it is now not far behind the excellent performance of the Nikon D5100. It easily outdoes the Canon T3i in the critical low ISO area of the DxOMark dynamic range tests.
While camera sensor performance is important it is only part of the image quality story. A quality lens helps produce digital photos that are sharper, with truer colour, and more contrast. For a photographer on a budget cameras such as the Sony Alpha 57 allow balance between the cost of the camera body and the lenses to use with the body. With the rapid development of digital technology the camera bodies quickly become outdated while quality lenses outlast many generations of DSLRs.
There is a wide range of lenses available for the Alpha 57, ranging from budget items through to premium quality Carl Zeiss designed lenses. Adorama lists pages of lenses for Sony DSLRS in their online catalog.
The Sony cameras are inheritors of the Minolta lens mount, so there are a number of older lens for Autofocus Minolta SLRs should work, widening the pool of available lenses.
One advantage of SLT is that it allows light go to the digital sensor and reflects some up to the Phase Detection AF sensor at the same time. In a DSLR to use this faster autofocus detection method the moveable reflex mirror has to be down in front of the digital sensor. This restricts most DSLRs to using the slower Contrast Detection autofocus system for Live View and video photography.
The Alpha 57 can save photos and videos to high capacity SDHC and SDXC memory cards as well as Sony ‘s proprietary memory sticks.
The Sony Alpha 57 offers good value for money at just over $600 from Adorama. The Alpha 57 is a capable DSLR of forming the foundation of a sophisticated photographic system with a variety of lenses and accessories available.