When the Digital SLR was created it took all the fundamentals of a traditional 35mm SLR and simply made it digital. Instead of capturing light on film the camera captures light on a sensor. In reality the technology hasn't changed that much, but the range of functions that a modern digital camera offers has.
Sony's latest offering and attempt at solving some of the problems is the Alpha A33 and Alpha A55. The two DLSR-like cameras solve the mechanical limitations of the mirror having to move out of the way every time you take a shot, by making it see-through. Pocket-lint spent a day with the new DSLT (Digital Single Lens Translucent) models to find out how the new tech worked and whether or not you need to check it out.
The tech is called Translucent Mirror Technology and basically allows around 70 per cent of the light coming down the lens to pass straight through onto the sensor. The other 30 per cent is redirected up into an electronic viewfinder, rather than optical, and dedicated autofocus sensor. Sony says the camera takes this light loss into account and changes the f-stop settings (by about a third) in the calibration algorithms to account for it.
The electronic viewfinder (EVF) also helps Sony battle a problem that Canon encountered when it tried a similar technology (called Pellix) in the 1960s, which meant the viewfinder was too dark to really see anything because of the loss of light. More on the viewfinder later.
The new translucent mirror tech isn't just about discovering a new way of doing things, but about giving the camera a number of advantages over traditional methods. Being able to create smaller cameras is one such advantage. Both the A55 and A33 are around 25 per cent smaller and lighter than a traditional Alpha model and that can only be a good thing in our books, so long as you still have enough camera to grip.
There are also less moving parts because you aren't having to worry about a mechanical mirror moving about inside your camera any more. That lack of movement means other things as well. The A55 can shoot 10 frames a second - something that is considerably faster than anything else in this category - all because the mirror doesn't have to move.
And those advantages just keep on coming. Because the live view is always on - a distinct advantage over a DSLR camera - and because of its translucent mirror technology, Sony states that you get constant autofocus in video on objects heading towards you at up to speeds of 50kph - handy for Pamplona. But always-on live view and 10 frames per second isn't necessarily going to make you dump everything and snap up the camera when it goes on sale in September.
In the hand the camera feels light and easy to manage. There are plenty of buttons and controls, more akin to a DSLR than the NEX range. The screen on the back tilts and swivels in virtually every direction, meaning you can benefit from that always on live view, and if you are used to shooting via the screen rather than the viewfinder it's certainly handy to have. It's perfect for shooting above crowds or awkward low angles.
The model will come either with or without a kit lens, and those opting to spend the extra bucks will get Sony's standard 18-55mm offering - what we were using here and what is used to photograph our hands-on pictures. Of course we don't have to tell you that you get the advantage of accessing all the existing Alpha lenses in circulation, so you don't have to worry about lack of accessories.
Turn the camera on and you're ready to shoot stills incredibly quickly. Video takes a few seconds longer to get going, and depending on how much you've shot (there is a limit of 29 minutes at any one time - as standard with most DSLR models) there will be some waiting at the other end too.
For stills the A55 comes with a 16.2-megapixel sensor (it's 14.2 megapixels for the A33) and that should be more than enough to create the shots you need with plenty of room to crop. Helping you make sure those shots are all in focus Sony has employed a number of technologies. There is a 15-point AF (autofocus) system for starters that can be localised to one spot, centred, or merely set to try and hit as many of those points as possible. This uses the dedicated AF sensor using a phase detection system. In our play the camera's AF system worked very well; auto focusing quickly when needed with little hunting even in some interesting lighting conditions.
Then there is face detection, smile detection, and a series of scene modes too, including portrait, landscape, and low light as you'll find on other Sony cameras. Photographers wanting manual control - don't panic - you get all of that as well; this is a DSLR-like camera. On the video front you'll get 1080i recording with the ability to save to AVCHD or MP4 and you'll be able to shoot in 16:9 and 4:3. There is an external mic slot.
Shooting a range of subjects - Sony organised sheep sheering, duck herding, and falconry sessions for us to test the camera out. Using the electronic viewfinder wasn't as distressing as we had expected to it to be and it actually provides plenty of information on the screen, as well as giving you a 100 per cent field of view. You will feel like you are flying a fighter plane however, mainly down to the fact that one of those bits of information is an on-screen spirit level so you can see when the photo you are about to take is horizontal and level. This is a common feature on higher-end DSLRs, but you don't normally get such a feature at this price point.
Snapping shots is - like the Canon 7D - a Gatling gun affair with the camera making plenty of noise even when you just opt for a single shot. The buffer performance depends on a number of factors like size of file and the SD or MemoryStick (it takes both) you are using, but the top line to shout about is 23 shots. We were able to easily shoot 10 shots of some ducks running towards us and then choose the best one later. All were in focus.
Like the company's NEX range and other Sony compacts, the A55 and A33 feature 3D sweep panorama, and that means you can swish the camera from left to right and capture 3D shots to display on your 3D TV. Other features worth mentioning that we didn't get to play with are built-in GPS as standard, that will automatically geotag your images, and an ISO range that starts at 100 and goes all the way up to 12800 or a mind boggling 25600 in Multi Frame NR mode.
£600 - 800
Sony is hoping the autofocus for video, the faster frame rate and other features like 15-point AF will help it win the battle against more conventional rivals. However, Sony isn't, it seems, 100 per cent confident that this plan will work with the launch of virtually identical cameras with a more traditional mirror setup.
The question is, will consumers go for it? From our brief play it's a great alternative to the DSLR models out there, but one that looks to offer something more than the NEX range recently launched. It will certainly catch the eye of the growing number of DSLR movie fans, but success will depend on fully supporting that video capture. Some may also prefer a traditional optical viewfinder, but Sony has catered for that with their other Alpha launches.
We are certainly looking forward to getting it in for a proper test, when we can really see whether the images and their quality have what it takes to be the camera to get this Christmas. The A33 is out at the beginning of September, while the A55 should be available at the end of September. Expect to pay around £600-800 depending on which setup you go for.