Although unmistakably 'Alpha', the A33 and A55 are significantly different to what has gone before - both in terms of Sony's DSLR products, and the market as a whole. The most obvious differences are a high-resolution EVF in place of an optical finder, and a fully articulated LCD screen - both firsts for the Sony Alpha line. For all their changes, they retain use of Sony's A mount, just like all the company's existing DSLRs.
The EVF is a necessary consequence of the translucent mirror and the location of its phase-detection AF array, but apart from a slight elongation of the viewfinder housing it is hard to distinguish from an optical finder at a casual glance at the camera's body. The fully articulated LCD screen however, is impossible to miss, and dominates the rear of the A33 and A55.
Positioned next to the last-generation Alpha 500, it is clear that Sony has managed to make significant reductions in bulk in the A55 (and A33) compared to its 'traditional' DSLR designs. Although the Alpha family resemblance is unmistakable, the new SLT cameras are shorter and narrower than previous designs, with a significantly reshaped handgrip.
In your hand
Despite its reduced bulk compared to Sony's Alpha DSLRs, the A55 is comfortable to hold, partly due to the fact that it's depth is almost exactly the same as earlier midrange models. The shorter handgrip may cause problems with anyone with particularly large hands, but for a camera of this size and weight, the A55's grip is more than adequate, and quite comfortable.
We would like a slightly more substantial thumb rest on the rear of the A55 though - depending on the size of your hands, the thin strip of rubber might not be quite wide enough to prevent accidental mashing of the nearby Fn button.
The A55 and A33 feature a large, high resolution EVF, with diopter correction and an automatic EVF/LCD switch sensor (visible as the dark rectangle beneath the eyepiece in this image).
This view shows the EVF with its soft rubber eyecup removed, which reveals the diopter correction wheel to the right of the eyepiece.
One of the best things about EVF displays as opposed to optical viewfinders is the much greater amount of shooting data that can be shown at any given time. The EVF in the A55 and A33 is excellent. The amount of information that can be displayed in the EVF (and LCD) can be changed using the 'display' button on the camera's rear. One of the most useful pieces of information is a multiple-axis electronic level, which shows both pitch and roll, overlaid on the screen image.
The A55's EVF is bright and large - significantly brighter and larger in fact than Sony's A550. It also compares very well against the EVF of the Panasonic Lumix DMC-G2 (arguably its closest competitor in this respect). The only serious complaint that we have is that the rainbow 'tearing' which is a characteristic of field-sequential displays is more noticeable (and therefore more of a problem) when using the A55 than the G2.
This tearing takes the form of an RGB 'rainbow' ghosting effect which becomes visible when the eye is moved around the viewfinder. The dpreview office is divided between those of us that find it obtrusive and unpleasant, and those of us that barely notice it, but everyone is agreed that the A55's EVF is slightly more prone to the effect.
The A55 uses the same battery as Sony's NEX-series compact mirrorless cameras. Despite a relatively low capacity (for its class) of 7.9Wh, the NP-FW50 is rated for between 330 and 380 images depending on EVF/LCD use.
Just to the rear of the battery compartment is a dual purpose SD/Memory Stick slot.
The A55 and A33 feature a fully articulated (not just fold down/out) LCD screen, which hinges along its lower edge, and can be completely reversed to protect the screen when the camera isn't being used.
Hidden under a rubber door on the left of the A55 are a HDMI port and a USB 2.0 socket. Images (still and moving) can be played back directly on Sony's Bravia televisions via the HDMI connection.
Unlike previous Alpha series DSLRs the A55 and A33 feature a movie mode. A direct movie shooting button is positioned on the rear of the camera, next to the exposure compensation and AEL lock buttons (which double as magnification controls in image playback).
On the left of the A55's top plate is the exposure mode dial. As well as the standard PASM modes this dial also provides access to the A55's high speed 10fps shooting mode, and its sweep panorama function.
Note also the separation of of the standard Auto mode from Auto+ which can use the camera's multi-shot modes.
The A55's built-in flash is fairly low-powered, at GN10, but when popped up, it sits fairly high above the camera body. This should help to reduce the risk of redeye in flash-lit portraits.
It can also operate in wireless mode, as the controller of a group of off-camera flashguns.
The A55's mirror is locked in the down position when shooting. It is sprung, however so that it can be moved out of the way for sensor cleaning.
We have found however that after manually unlocking the A55's mirror we can persuade it to sit slightly outside of its clip - i.e. at a slightly less acute angle to the sensor than it should be. This causes severe image ghosting but is otherwise impossible to detect.
A plug for an accessory microphone is hidden away at the lower right corner of the camera's left side, under a rubber cap. Sony has developed two clip-on microphones for the A33 and A55 - the ECM-ALST1 and ECM-CG50 (sold separately).