Sony Alpha a100 review
Featuring a Sony-manufactured 10MP CCD sensor, the A100 finds itself rubbing shoulders with the Nikon D200 and Pentax K10D. It’s worth mentioning, however, that Sony is the major supplier of CCDs to the DSLR market – in fact, most of the current mid-range DSLRs (including the Nikon D200), except Canon and Olympus, contain Sony chips.
In addition, the Alpha 100 benefits from Sony’s Super SteadyShot technology, which we previously knew as Konica Minolta’s AntiShake CCD. This image-stabilisation system moves the CCD instead of the optics to counteract camera shake. Sony has refined the system to offer slower shutter speeds of up to 31/2 stops slower than we’d normally achieve – useful for low light and/or long lenses. As a rule, the slowest shutter speed would traditionally have been set at around the same number of the lens focal length, ie 200mm lens and 1/250sec. With this system, it would be around 1/25sec. Of course, we need to allow for the equivalent focal length because of the smaller sensor; so if the lens is 300mm, the slowest recommended shutter would be about 1/40sec.
Expanded Dynamic Range
Another major feature of the camera is an expanded Dynamic Range (DR) feature, which maintains detail in shadows and highlights that would normally be lost in high-contrast conditions. For example, with a backlit subject, you’d usually spot-meter for it to preserve the detail, losing the background highlights that fall outside the sensor’s recording capability. The DR function is theoretically able to record some of that lost detail by isolating those pixels and amplifying or reducing the signal.
This is similar to the idea of ‘digital flash’ seen in compact cameras from Nikon and HP, as well as in many camera phones. There’s little reason, other than technological limitations, why all cameras could not adopt this by splitting a CCD into independent zones and adjusting exposure on a pixel-by-pixel basis, thus eradicating under- and overexposure and loss of image detail. One day, everyone will have photographs with perfect tonal ranges.
Like the Dynax 5D, Sony has kept the eye-start function: when you hold the camera to your eye, the LCD shuts off and the viewfinder information displays. A new addition is that the AF also kicks in at this point so the subject is in focus before your finger even touches the shutter-release button. Actually this is something that Konica Minolta had in the Nineties; Sony has just brought it back. Additionally, every time the camera is turned on, the CCD shakes to dislodge any dust that might have attached to it, which is also combined with a new anti-static filter over the sensor to discourage dust from landing in the first place.
Inside the camera is a new Bionz processor that Sony claims offers reduced noise, accurate colour, contrast and saturation to produce ‘vivid yet natural’ images. Sony has also brought its battery know-how to the table and the Alpha 100 comes with a long-life stamina battery, offering 750 shots per charge.
Finally on to the lenses. A few are available, including a 18-70mm kit lens (£699 for body and lens) and a 70-300mm available as part of a dual lens kit (£849). The year ahead should see a barrage of 20 lenses including those Carl Zeiss optics. Sony took over the Minolta lens factory, and all the lenses rebranded. The two Sony lines include the DT range and the premium G range – note that the lettering continues that of Konica Minolta lenses.
The Sony Alpha range uses the old Minolta AF mount, henceforth to be known as the Alpha mount. The good news is that the two are mutually compatible, so Konica Minolta users still have access to new objectives as and when they appear. Even better news for the Konica Minolta fan is that the new Carl Zeiss T* lenses will also be compatible, offering potentially world-beating German optics for the first time.