Several months ago Sony announced the SLT series of two digital single lens cameras. The series is built around the concept of a non-reflex mirror with the promise of faster framing rates and better auto focus capabilities. The Sony SLT-A55VL (street price $849.99) has been released first and I’ve spent a long weekend getting to know it.
My first impression is that Sony has created a very small form digital single lens camera. First glance had me thinking that the camera would be cramped to hold and that my fingers might accidentally activate buttons. Both of these concerns proved to be misplaced, the body fit well into my hands and the balance was excellent. Overall the A55 with the kit 18-55 lens mounted seemed very substantial and quite solid.
Before I dive into the unique features of this digital camera I want to comment on a few of Sony’s nicer touches. The swiveling rear LCD combination viewfinder / monitor is really very sharp and offers a decent view even in moderate sunlight. The electronic eyelevel viewfinder may not be quite the same as the view through a direct view prism, but it was more than sufficient. I liked the eyelevel finder’s artificial horizon display which helped me keep the camera level while handheld.
Powering up the camera was almost instantaneous. The rear LCD displayed relevant settings information as a border all the way around the live image view. The live image switches from the rear LCD to the eyelevel finder when the camera’s sensors detect that you have raised the camera to your eye.
Operationally the A55 is much like any other single lens digital camera. Buttons and switches are marked with familiar icons and labels; the ubiquitous four-way controller is under the right thumb just as on any other camera, the command and mode dials are just where I would expect to find them. In short, when the camera is up to the eye a photographer familiar with a Nikon or Canon camera won’t fumble very much when seeking out the controls.
And now let’s review how the Sony A55 is very different. So far I have been referring to the A55 as a Digital Single Lens (DSL) camera, leaving off the “reflex” (R) part of the description applied to other more traditional models.
In a traditional camera there is a mirror that hangs down in the image path between the rear of the lens and the camera’s shutter and image sensor. This mirror reflects the incoming image up into the eyelevel viewfinder and onto focus and exposure sensors. Each time the shutter button is tripped this mirror must pop up out of the way so that the image can pass though to the image sensor. After the shutter opens and closes the mirror resets into the image path and the eyelevel finder view is restored. This reflexive up and down action gives us the “R” in DSLR.
Sony’s A55 does indeed have a mirror sitting in the image path between the lens and sensor. However this mirror doesn’t move up and down to get out of the way when the shutter is tripped. The mirror of the A55 is a half mirror so images both reflect up from it and pass through it as well. Think of mirrored sunglasses or a two-way mirror as an example. But why did Sony think this was a better idea than a moving reflex mirror?
Reflex mirrors have a blackout moment each time the shutter button is tripped. For a split second not only is the photographer blind but so are the focus and exposure sensors. For still photography captured at a brisk five or six frames per second this isn’t a huge issue. However if the manufacturer wants to offer a camera with up to 10 frames per second the blackout period would almost exceed the viewing period so focus and exposure are less certain. Plus there is an enormous amount of damping required to prevent internal vibrations that would lead to blurred images – part of what makes traditional cameras capable of 10 FPS so expensive.
The biggest plus of a non-reflex mirror design is found in the video mode. A traditional camera design requires that the mirror be up and out of the way for video capture. With the mirror up the focus and exposure sensors are blind and the camera must be manually focused or rely on not so good contrast-based autofocus. Since the Sony A55 mirror is always down and in play the focus and exposure sensors are always operational. This means that the Sony A55 can capture 1080p HD movies with fully automatic focus and exposure, something that no other DSL can do as well.
However there is a problem that I had while using the camera at high speed. The viewfinder can’t keep up with the picture taking rate so while shooting at high speed what I was seeing was always the last image captured, not the live view. I’m not sure if this behavior will have a bad effect on a photographer’s timing during sports shooting, I wasn’t able to shoot under those conditions. But it was definitely an odd experience to aim a camera based on where the subject just was rather than where the subject is right now.
In operation I found that the A55 in movie mode does out perform most other DSLR’s that I’ve used. The video isn’t better quality (we’ll see that in a moment) but the experience of capturing it was by far effortless.
I did have several concerns with the Sony A55. Many of my issues probably come from the short time I had with the camera and would likely go away with better familiarity:
The A55 offers in-camera HDR still image capture. The camera will take several fast exposures at a wide range of settings and then combine them into one with greater tonal range. The results were good about 40% of the time. I found that most often the camera’s HDR results were too punchy with blooming reds and warm colors. Niggling detail – once set to HDR the photographer has to manually turn it off even after power down and restart. Forgetting to do this will result in the camera taking an HDR image the next time it is turned on.
Video colors seemed to be strong too. It my be that I just like more realistic contrast and color, but the A55 seems to add some “pop” to warm colors in video just as it did in HDR. I didn’t care for it but my wife actually liked it so it is a matter of personal taste.
For an advanced shooter Sony’s reliance on pictorial descriptions of shooting modes within the menu system only slows things down. I believe that even someone new to using exposure modes will soon tire of the two-beat delay before the pictorial screen moves on to the actual menu screen.
I have some pretty good video editing software from Nero and Adobe. However the Sony video output couldn’t be opened with either brand. The AVCHD video format captured by the A55 seems to require a first pass through the included Sony software before my video suites could manage the movies.
Conclusion: The Sony A55 is right on target for two types of photographer. First is the photographer moving up from a compact digital camera that will appreciate the simple menu system with pictorial assistance. The second group is the family photographer who wants a highly reliable still camera with easier than average video capture. The photographer who only needs video on few occasions and for short duration will likely be drawn to a Nikon or Canon models for their larger system of accessories and lower entry cost.