The Sony Alpha A35 is a fix for the high power consumption and the related overheating of the digital sensor issues with their Alpha 33, released in October last year.
The Alpha 35 uses the same battery as the model it replaces, the Alpha 33, and according to DxOMark there is only a small gain in the image quality of the sensor. The likely reason for the new sensor is that it uses less power and produces less heat.
The Sony Alpha 35 is for entry level Digital SLR camera buyers. Pentax and Nikon use the same 16 megapixel APS-C sensor in higher spec DSLRs, but in the Alpha 35 Sony have configured it to give similar performance to other entry level Digital SLRs according to DxOMark lab tests.
Viewfinder System
The Alpha 35 is a Single Lens Translucent (SLT) camera because it does not have the traditional moving mirror and optical viewfinder of the familiar DSLR.
Sony’s translucent mirror system diverts some of the light from the lens up into the normal pentaprism area where it is used for metering and focusing. The viewfinder in a Sony SLT digital camera is an electronic version instead of the DSLR’s optical viewfinder. It uses the Live View images and displays them in the viewfinder.Photographers can choose to use Live View on the rear LCD screen or in the viewfinder.
“Our Translucent Mirror Technology is one of the most significant SLR structural changes in more than a decade,” said Kristen Elder, director of Sony’s digital imaging business group.
Using the viewfinder photographers can hold the camera securely, reducing camera shake with the human tripod technique. Sony’s sensor image stabilisation system aids in taking sharper photos.
The viewfinder is a benefit for photographers shooting movies without a tripod as this also helps reduce the jumpiness common in home movies. It is easier to support the camera as movie takes are usually longer than taking still photos.This is particularly apparent with heavier telephoto zoom lenses as they are difficult to hold using the normal compact digital camera reach method.
For traditionalist photographers who might prefer an optical viewfinder Sony have made the electronic viewfinder more attractive. the Tele-zoom High Speed Shooting feature that magnifies the centre of the photo area in the viewfinder by about an effective 1.4x magnification
Movie Mode and Focusing
Focusing in movie mode is an area where DSLRs still need development.
Digital SLR cameras use the Phase Detect AF system for fast accurate focusing in conjunction with the optical viewfinder system. This happens when the reflex mirror is down in front of the digital sensor. This is fine for still photos as the mirror moves out of the way as part of the shutter operating process.
For continuous viewing of the sensor output in Live View and movie modes the mirror stays up preventing the phase detect AF system from working. Most digital cameras, including some DSLRs, use the normally slower and less precise Contrast Detection AF system. Some DSLRs rely on manual focus only for movie mode.
In the Sony SLT-A35 the translucent mirror approach allows the Phase Detection AF to work for HD movies as well as for normal still photos using either the viewfinder or Live View on the LCD.The Sony Alpha 35 has fast accurate continuous focus in movie mode making it ideal for shooting fast moving subjects.
One of the reasons for using DSLR cameras to shoot movies being able to use telephoto lenses so video photographers can use the selective focus effect, so useful in story telling.
Sensor Performance Tests
Comparing the new Alpha 35 to the older Alpha 33 in the DXoMark Lab shows little real difference.The Alpha 35’s digital sensor produces less digital noise than the model it replaces indicating that Sony’s new 16 Megapixel digital sensor is excellent in this area.
Looking at the difference in noise performance in more detail between the Sony, Nikon, and Pentax entry level cameras shows the Pentax Kx is better at very high ISO settings, but at more commonly used ISO settings the difference in noise between the three cameras is minimal.
The detailed results of the DxOMark dynamic range tests at the bottom of the article shows that at ISO settings from about 400 and lower the Sony Alpha 35 has the edge over the Nikon D3100.
Dynamic range tests measure the range of light from the brightest white to the darkest black the sensor can record.The effect of dynamic range may not be immediately obvious in a photo but it shows in how the camera reproduces the subtle range of tones in either the highlights or the shadows. When the sensor hits its limit of dynamic range these tones are shown as all black or all white.
The Sony Alpha 35 has the most megapixels with a 16 megapixel sensor compared to the Nikon D3100’s 14 megapixels, and the Pentax Kx with 12 megapixels.The main advantage of more megapixels is for printing extra large size photos, for web use and normal size prints the higher resolution is not needed.A disadvantage of having more megapixels is larger image file size that use more space on memory cards and computer hard drives.
Uses Less Power
Sony told the photographic press, “Reductions in power consumption boost the camera’s battery life to a generous 440 still shots (approx. when using the rear LCD panel) between battery charges – a 30 percent increase over its predecessor.”
This is only part of the story, Sony have reduced the Alpha A35‘s power consumption more dramatically. Possibly Sony do not highlight the poor performance of the Alpha 33.Sony say on their web site that the number of still shots using the Tru-Finder™ electronic viewfinder jumps from 270 for the A33 to 440 for the A35 under controlled test procedures. In real life the number of photos per battery charge will vary.
Using less power should reduce any problems with overheating of the digital sensor.
Pricing and Availability
The new Sony Alpha 35 interchangeable lens camera will be available this August with an 18-55mm kit zoom lens (model SEL1855) for about $US700. The Alpha 35 will also be offered as a body-only (without kit lens) for about $US600
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