General

Body

The first contact with the small camera is somewhat sobering - lots of plastic combined with rubber and an insufficient finish especially when talking about the swivelling screen which does not snap in completely but stays about a millimetre back. Nevertheless, the small camera feels comfortable to hold although at least my little finger is out of work - which is of course no surprise regarding the size of the camera.

[1] Flash pop-up button, [2] Lens release button, [3] Focus mode switch, [4] Preview button

The front part of the body shows the usual button layout. On the left side there is a button for the pop-up flash, for the release of the lens and for the switch between manual and automatic focus. Fortunately, the DOF-button wasn't sacrifice for the compact size.

[5] Mode dial, [6] MENU button, [7] Control dial, [8] Power switch plus Shutter button, [9] D-RANGE (Dynamic range) button, [10] FINDER/LCD button, [11] For shooting:AE lock button / For viewing: Zoom in button, [12] For shooting: Exposure button /For viewing: Zoom out button or Image index button, [13] MOVIE button

The top of the camera is also structured and user-friendly. On the left hand side there are only the mode dial and the menu button, while on the right hand pane just below the control dial you can find the release button with integrated power switch. In addition, there is surprisingly a separate button for the D-Range which can be used to adjust the dynamic range and to turn the HDR-functional on. In my humble opinion this button is rather superfluous and the next button to switch between the LCD and viewfinder is more useful. The last three buttons on top are in a row from left to right, the movie, the exposure compensation and the AEL buttons.

[14] For shooting: Fn (Function) button / For viewing: (Image rotation) button, [15] Control button including Display-, White balance-, Drive and ISO- plus OK-button, [16] For shooting: Focus Magnifier button / For viewing: Delete button, [17] Playback button

The back of the camera is dominated by the large and swivelling 3'' LCD. However, on the right there is still enough space for the Fn button, the control plus OK button and the playback as well as delete button. By the way, the Fn button is pretty useful as it controls further important parameters like the drive and metering mode. The control button consists of four buttons for changing the LCD display, setting the drive mode as well as white balance and ISO. The OK button in the middle can be also used for focusing which is useful in unusual positions when using the swivelling display.

Generally speaking, the button arrangement is satisfying simply because it's possible to change all relevant parameters during photography with just one hand. Furthermore, the menu is intuitive - at least for existing Sony users. However, as mentioned, the used materials are not that reassuring.

Technology Facts - SLT

What makes the Sony SLT-A33 so special? The following image should help to explain Sony’s SLT approach.

As with all DSLR cameras, the light passes through the lens and strikes the translucent mirror. One part of the light is falling on the sensor of the camera and the other part is redirected by the fixed mirror to the auto focus module. This simple but ingenious technique allows the use of live view and phase-detection AF at the same time and the elimination of the “mirror swing” allows more frames per second and reduces the risk of dust on the sensor.
With a few words - an EVIL camera with phase-detection autofocus

Viewfinder

Unlike conventional DSLR cameras and just like EVIL cameras the Sony has an electronic viewfinder with a diagonal of 1.1 cm and a resolution of 1,152,000 points. It has a coverage of 100%, a magnification of approx. 1.1x and a dioptre correction from -4.0 to +4.0. Additionally, grid lines as well as a histogram can be superimposed on-demand.

Compared to an optical viewfinder there are advantages and disadvantages. The electronic viewfinder appeals brighter due to a sort of "low-light amplifier" and gives more control in very low light situations but at cost of a rather noisy electronic viewfinder image. Furthermore, it has an exemplary coverage of almost 100% and it is customizable with different types of guiding lines as well as a histogram. The electronic viewfinder is very useful in bright weather conditions for playback - external displays always have problems in such situations.
However, the electronic viewfinder has a weakness in sports photography because of the comparatively slow refresh rate - an optical viewfinder has none, of course - which may make it difficult to track fast target objects. However, the viewfinder of the SLT A33 is already one of the faster implementations so far.
Last but not least, all electronic thinks reduce battery life and the electronic viewfinder is - like a live view display - power-hungry.

Battery

Sony states that the included NP-FW50 Li-Ion battery provides sufficient energy for approximately 270 images with viewfinder and about 340 images in live view mode. This value is based on CIPA standard and actually not an overly spectacular statement although you should better expect 10% less in normal field conditions, more so when using Live-View and especially the movie mode. The supplied battery charger BC-VW1 takes approx 2.5 hours for charging which is about average. The simple battery indicator that can be displayed in the viewfinder as well as on the external display has 5 levels and seems to be reasonably accurate.

Pop-up Flash

The built-in pop-up flash unit with a sufficient guide number of approx. GN10 at ISO100 is TTL-controlled and matches with the Sony 18-55mm F3.5-5.6 SAM kit zoom lens. It supports auto flash, fill-flash, slow sync and rear flash sync with a maximum sync speed of 1/160s and high speed sync with an optional compatible accessory flash. The flash output can be adjusted in 1/3 steps up to +/-2EV and the flash pops up automatically when taking pictures in automatic mode. The flash coverage is fairly good for an internal flash unit but for the real thing you should consider an external system flash unit.

AF Performance

The small Sony comes with a TTL phase-detection system including 15 points and the standard AF modes continuous, single shot, automatic and manual focus. All in all, the AF speed and the accuracy of the Sony SLT-A33 are very good, even in dark conditions as well as in continuous AF mode. Thanks to the translucent mirror technology the phase-detection system is available without interruption and this is a unique selling proposition for a camera in this segment.

Metering system

The metering systems doesn't offer anything special beyond what we are used to from other consumer DSLRs. Multi segment, centre weighted as well as spot metering are available. The metering reliability is much higher than average and the super-imposed live-histogram makes it easy to control even difficult lighting situations. This is certainly one key differentiator compared to conventional DSLRs.

White Balance

It's difficult to evaluate the performance of the auto-white-balancing in studio scenes. The results can vary greatly depending on the setup so we don't really look into a standardized process here. In field conditions the AWB system did a good job but like the rest of the bunch it struggles in artificial light conditions where you should either prefer to fall back to a flash unit (thus neutral light) or manual WB. Alternatively WB bracketing is also provided. However, you can choose between AWB, the known general presets and your custom white balance as well as setting the colour temperature or a colour filter.

Dust Removal System

The Sony SLT-A33 comes with an anti-static coating and a sensor shift mechanism to prevent dust and debris on the sensor. Unfortunately the efficiency of the system isn't quite as good as with an high-frequency sensor cleaning unit. However, this time the solution is complemented by the translucent mirror technology which reduces the risk of ruined pictures due to missing mirror swing. Dust has simply far lesser chances of finding its way to the sensor.