Sony Alpha DSLR-A900 Review
Super SteadyShot (Sensor-shift Image Stabilization)
The DSLR-A900 features Sony's 'Super SteadyShot' sensor-shift image stabilization system (a development of the 'Anti-Shake' system we first saw on the Konica Minolta 7D) - something many were skeptical was even feasible with a full frame sensor in a camera this compact (kudos Sony on that clever bit of engineering). This system works by moving the sensor in the opposite direction to the sensed shake movement of the camera.
The stabilization test
This test is designed to produce a determination of the relative improvement you should expect using the SteadyShot system compared to with it switched off. Twenty hand-held shots are taken of a static scene at reasonable shutter speed (1/400 sec in this case), ten without stabilization, ten with. The shutter speed is then decreased by a stop and twenty more shots taken, this is repeated down to 1/10 sec. The test chart was approximately 2.4 m away from the camera.
The resulting eighty images were then inspected and given a blur score from zero to three where zero represented a very blurred image and three a sharp image with no noticeable blur (see crop examples below). Obviously the amount of blur which is acceptable will depend on your personal taste and the final image size (for instance a '2: Soft' will still look fine as a 4x6 print or in a web gallery). Example crops from these four blur scores can be seen below.
|0: Very blurred||1: Blurred|
|2: Soft||3: Sharp|
Hand-held, no stabilization (24-70mm, 70mm focal length)
The A900 and 24-70mm ZA is not a lightweight combination, tipping the scales at just short of two kilograms, and as this test shows, getting sharp results when holding the camera in one hand was only possible at 1/400 sec, falling rapidly so that by the time we're down to 1/50th sec we're getting virtually no usable shots.
Hand-held, with stabilization (24-70mm, 70mm focal length)
With 'Super SteadyShot' switched on you can see an immediate improvement. Even down to 1/15th second we're getting at least one sharp shot in four, and almost all are usable to some degree (with just a little softness due to camera movement). As a result of more extensive testing we estimate that the Super SteadyShot system can be consistently relied on to deliver a 2 to 2.5 stop advantage, and can mean the difference between 'usable at a pinch' and 'totally blurred' results at shutter speeds well below the 'one over focal length' rule.
- 20 Photographic tests (Noise)
- 21 Photographic tests (Noise)
- 22 Photographic tests (Noise)
- 23 Photograpic tests (DR)
- 24 Photograpic tests (DR)
- 25 Photograpic tests (Fall off)
- 26 Photographic tests
- 27 Compared to...
- 28 Compared to (JPEG)
- 29 Compared to (JPEG)
- 30 Compared to (JPEG)
- 31 Compared to (RAW)
- 32 Compared to (RAW)
- 33 Compared to (RAW)
- 34 Compared to (High ISO)
- 35 Compared to (Resolution)
- 36 Conclusion
- 37 Samples
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