Why You Can Trust CNET Sony Alpha SLT-A33 review: Sony Alpha SLT-A33
A great entry-level digital SLR, the A33 offers fast shooting speeds and very good image quality for most intents and purposes.
- Webby Award honoree, 2x Gold Telly Award winner
Sony Alpha SLT-A33
The Good
The Bad
The Bottom Line
When Sony announced to the world its latest digital SLR pair, the A55 and baby brother A33, people began to sit up and notice. These two cameras use a different mirror technology to traditional SLRs, called a translucent mirror (or a pellicle mirror). While it's not new, it's the first time it's been used on a digital SLR of this calibre. For more on how the technology actually works, click here.
The A55 and A33 are very similar to each other, with the A33 only losing out in terms of megapixel count (14.2 vs. 16.2 megapixels on the A55), continuous shooting speed (7fps vs. 10fps on the A55) and lack of GPS unit.
Design and features
The A33 is shaped just like any other digital SLR from Sony. Around the outside is a slightly textured plastic, which encases the substantial hand grip; all the other control buttons are plastic as well.
Things start to take an unexpected turn when inspecting the 3-inch, 16:9 aspect ratio screen (incidentally at a resolution of 921,000 dots), which can tilt and flip back in on itself. It's streets ahead of screens on other entry-level models, including the Nikon D3100, which is one of the strongest competitors for the A33.
The other big difference between this camera and the array of entry-level SLRs on the market is the electronic viewfinder, rather than an optical one. It provides 100 per cent field of view and is high resolution, but it's definitely something that you either love or hate. Shooting options and an electronic level can be overlaid on the image you see through the viewfinder, and the "always on" Live View mode means you can adjust your exposure and preview what the image will look like before taking an image. While this all sounds wonderful in theory, the viewfinder is very small and it doesn't feel like a true SLR experience.
On the mode dial are the standard array of shooting options anyone would expect, including full PASM control, two automatic modes, non-flash, scene, continuous and 3D sweep panorama mode. This camera is well equipped for most connection options, including a mini-HDMI port, mini-USB, external microphone input and remote trigger release. There's an instant movie record button around the back that starts the 1080i/30fps video recording in AVCHD format.
HD recording is limited to automatic exposure control. The A33 can also hit ISO 25,600 in boost mode, though it's unlikely that anyone would want to use this unless absolutely necessary.
Like other Sony SLRs, the A33 contains an image stabiliser inside the body, rather than in the lens. This means that any lens attached to the camera will be stabilised. As for files the A33 can produce, there's standard JPEG at 3:2 or 16:9 aspect ratios only and ARW RAW files, which can be read by the latest versions of Adobe Camera Raw and Lightroom.
Compared to
| Nikon D3100 | Canon 1000D | Sony A33 |
|---|---|---|
| 14.2 megapixels | 10.1 megapixels | 14.2 megapixels |
| 3-inch, 230,000-dot LCD | 2.5-inch, 230,000-dot LCD | 3-inch, 921,000-dot articulating LCD |
| HD video (1080p, 24fps) | No HD video | HD video (1080i, 30fps) |
| 11-point AF | 7-point AF | 15-point AF (phase detection) |
| 3fps | 3fps | 7fps |
Performance
General shooting metrics (in seconds)
- Time to first shot
- JPEG shot-to-shot time
- RAW shot-to-shot time
- Shutter lag
Continuous shooting speed (longer bars indicate better performance)
Sony rates the battery for the A33 to last for 270 images when using the viewfinder and 340 when using Live View. While the A33 definitely does live up to its claim of shooting 7fps in continuous mode, the camera did slow down and stop taking images once it had snapped 16 JPEG shots in a row.
Image quality
The A33 produces accurate exposures for the most part, and has an impressive dynamic range. Colours are mostly accurate (though the screen on the camera itself is perhaps a bit too punchy) and the camera copes well up to ISO 800. ISO 1600 and 3200 produce very usable shots, too. Automatic white balance is pleasingly accurate.
While the translucent mirror system promises fast AF, the kit 18-55mm lens had a bit of trouble during our tests in focusing quickly and accurately in low-light situations, particularly at night. It took at least one second for the camera to grab onto a focus point, and sometimes continued to seek focus even if an appropriate point was found. Continuous autofocus also was a little troublesome.
Compared to other kit 18-55mm lenses on entry-level models from Canon and Nikon in particular, the Sony version is a little less refined, showing up chromatic aberrations and with more edge softening. For most purposes though, it won't present too much of a problem, particularly if you won't be making large prints or inspecting images at 100 per cent magnification.
RAW vs. JPEG
The A33 processes its JPEG files very well, with a little extra sharpening thrown into the mix. (Credit: CBSi)
The A33 produces very good video files at its native 1080i resolution. When using the 18-55mm lens, it does show up its weaknesses more prominently, like its lack of edge in sharpness and fringing. There's no manual controls available for video recording and audio does sound a bit tinny from the internal microphone.
Sony has revealed that the A33 and A55 are limited to recording nine minutes of video in normal operating conditions (20 degrees Celsius) or six minutes (above 30 degrees Celsius). These times are increased to 29 minutes when turning off the internal image stabilisation. This limitation is due to the translucent mirror technology.
Image samples
Click each image for full-sized samples from the A33. No post-processing has been done to alter these photos. Exposure: 1/50, f/5.6, ISO 1600 |  Exposure: 1/30, f/5.6, ISO 1600 |
 Exposure: 1/80, f/8, ISO 100 |  Exposure: 1/50, f/4.5, ISO 200 |
Conclusion
A great entry-level digital SLR, the A33 offers fast shooting speeds and very good image quality for most intents and purposes.