Sony Alpha SLT-A33L camera
Camera technology is changing for the better these days. While the digital SLR or DSLR is normally the weapon of choice for the serious or professional photographer, a spate of new cameras has been challenging this notion.
The Micro Four Thirds interchangeable lens cameras started it. Micro Four Thirds cameras usually have CMOS sensors, but vitally, the sensor size is smaller than even an entry-level DSLR. Even Sony's own NEX series is another example: a camera that uses a DLSR-size CMOS image sensor in a mirror-less, compact and lightweight body.
Each of these technologies has certain advantages - typically a smaller size and lesser weight as compared to a DSLR. But the Alpha SLT-A33L (and its big brother, A55L) takes things to a new level. The A33 is not much smaller or lighter than the average DSLR, but what it does do, is open up a super-fast continuous shooting mode (with continuous auto focus for each shot) in a price bracket that 'proper' DSLRs can't dream of matching.
A number of ground-breaking technologies enable this. For starters, the translucent mirror. In a conventional DSLR, the mirror stays down at a 45-degree angle to divert light upwards into the viewfinder and to the fast, phase-detection auto focus system. When the shutter button is pressed, the mirror flips up, allowing the light to pass through to the image sensor.
This is why the viewfinder in a conventional DSLR goes blank while shooting. Also, the mechanical movement of the mirror is a comparatively slow movement when compared to the actual recording of light, which contributes to the slower frame rate of entry-level DSLRs.
In Sony's system, the mirror just stays in place: most of the light passes through to the image sensor, while a portion of the light is diverted upwards towards the autofocus system and to generate an image for the electronic viewfinder (EVF).
Since the mirror is always down, the slow mechanical mirror flip movement is cut out of the equation and the recording of each image can be much faster. In high-speed mode, the A33 can take 7 frames per second at full resolution. Since the mirror stays down, the autofocus engine is always active.
Rather unbelievably, the camera can focus each frame while shooting in high-speed mode, i.e., 7 times per second. This kind of frame rate and autofocus speed can only be matched by high-end professional DSLRs that cost thrice as much as the A33.
Crucially, the video recording features are also enhanced by the mirror. Since the AF system is always active, the A33 can continue to focus while shooting video: something which conventional DSLRs cannot do - the mirror has to stays up while shooting video to let light through to the image sensor. Stangely, the A33's video is limited to 1080i rather than 1080p full HD for some reason.
It also has an amazing panorama and 3D panorama mode, in which you just have to sweep the camera from left to right while the camera fires off some quick shots and instantly stitches them together into one image.
Finally, in the A33, the image stabilization system is inside the camera, not in the lens (sensor-shift image stabilization, rather than lens-shift). This means that the image stabilization stays active, no matter what lens you use with it. The A33 ticks all the right boxes then: it has great battery life, all the advantages of a DSLR, a flip out screen and superlative image quality.
However, the biggest gripe that any DSLR user will have when switching to the A33 (or A55) is the lack of an optical viewfinder. Even though the EVF is sharp, has 100% frame coverage and has loads of extra information neatly displayed, it doesn't have the charm of an optical viewfinder.
The A33 is a fantastic achievement, but it will stay confined to the hands of the amateur photographer rather than the professional.