Conclusion - Pros
- Excellent 2.4 million-dot OLED EVF
- Versatile full-time live view system
- Very high-resolution 24MP CMOS sensor (but see caveats in 'cons', below)
- Exceptionally 'deep' feature set including Auto HDR and Sweep Panorama
- Class-leading video resolution
- Solid, well thought-out ergonomics
- Fast and responsive operation
- Very good continuous shooting performance (particularly with UHS-I memory card)
- Efficient SteadyShot INSIDE image stabilization system
- In-camera GPS
- Good battery life
Conclusion - Cons
- In-camera JPEGs don't show off the 24MP sensor to its best extent
- Comparatively strong noise reduction at medium and high ISO settings
- Very noisy raw files at high ISO settings
- Little control over high ISO noise reduction in JPEG mode ('auto' or 'weak')
- Limited control in 12 fps continuous shooting and movie modes
- No live view in 8 or 12 fps continuous shooting modes makes accurate panning very difficult
- Menu system a little confusing (hard to orientate yourself sometimes)
- Slightly 'laggy' menu system and UI.
- Awkward to navigate between stills and movie playback modes
When we reviewed the original SLT, the SLT-A55, at the tail end of 2010, we were impressed by how well thought-out its operational ergonomics were, given the newness of its key technology. Full-time live view mode was (and still is) addictively useful compared to the clunky compromise that we had become used to with conventional DSLRs, which require their mirrors to be locked up, disabling eye-level image viewing and phase-detection AF. The SLT-A77, like the 55, has no such limitations. Live view and autofocus operate full-time, and if you prefer eye-level viewing to using the rear LCD, you'll love the A77's exceptionally bright and detailed OLED EVF (which is reason alone to upgrade from an A55 or A35 in our opinion).
As usual, it is the A77's high speed shooting modes which have grabbed the most attention, but again, we find ourselves celebrating other, less flashy aspects of the camera's feature set. Its excellent EVF, versatile and intuitive live view and AF system, and its solid, reassuringly well thought-out operational ergonomics are all better reasons to buy this camera. In some shooting conditions, when viewed at 100% on screen, JPEGs from the A77 look less than fantastic, but sharpness (if not detail capture) can be tweaked, and an incredible amount of detail can be drawn out of the A77's raw files. It's a different story higher up the ISO sensitivity scale though, and we're not very impressed by the A77's pixel-level image quality at ISO 3200 and above compared to its competitors. There are better low-light cameras out there, some of which (like the Nikon D7000 and Pentax K-5) use Sony's 'last-generation' 16MP sensor. Naturally, of course, one of the benefits of Sony's SteadyShot INSIDE image stabilization system is that in a lot of situations, you might not need to reach for those high ISO sensitivity settings too often.
Overall the A77 is a logical, and successful upgrade to the pioneering A55, and one that should make a lot of enthusiast photographers very happy. If you're interested in the A77 as a sports and fast-action camera though, don't be blinded by its fast framerates alone. The A77 is very good, but in our experience the more conventional Canon EOS 7D and Nikon D7000 both offer slightly more reliable AF tracking and framerates which although slower than 12fps, are still plenty fast enough for most applications.
As far as image quality is concerned, the A77 is a camera with a split personality. On the one hand there's the A77 in JPEG mode, and on the other there's how it performs in raw mode. The two personalities are rather different, and you should manage your expectations accordingly.
Shared with the NEX-7, the A77's 24MP CMOS sensor is new, and at the time of writing, the highest-resolution APC sensor available in any camera. We're not completely sold on the need for this pixel count in a camera like the A77, but the potential benefits of a higher pixel count are obvious - higher resolution images, with more potential for cropping post-capture, or making very large prints. The reality is that the A77 produces image quality at low ISO settings which is at least good enough for general use, and sometimes stunning. As already noted, however, we're unhappy with the mushy JPEG rendering in all but the most favourable of conditions, and very disappointed by intense noise towards the top end of the A77's ISO sensitivity scale.
As you can see from the graphs and images on the noise page of this review the A77 is unequivocally noisier than its competitors both in terms of measured and visible noise. If you're a JPEG shooter, you won't see much actual noise until you get to the A77's highest ISO sensitivity settings, but you will see the ugly effects of its noise-reduction system, which takes a pretty significant bite out of fine detail. Even at the A77's lowest ISO sensitivity settings we're disappointed by the mushiness of its JPEGs in everyday shooting, and for critical work we'd always recommend shooting in raw mode if possible. You can see detailed examples of the difference made by shooting raw on this page.
Some good news though - as regards the 'ghosting' issue, which generated a lot of comment around the time the original SLT-A55 was released, we're pleased to report that in the thousands of frames that we've shot with the A77, it is completely absent, even in shots where we would have expected to see it in images from the A55/A35. Sony isn't revealing any details, but a spokesperson did tell us that improvements have been made to the SLT design, and its clear that whatever those improvements are, they have done the trick.
Ultimately, while it is true that at pixel level, both JPEG and raw files from the A77 show more noise at medium and low ISO sensitivity settings than some of its competitors, noise is far - very far - from being the full story. By any sensible, practical standard, at the low end of its ISO sensitivity scale the A77's image quality is very good. With 24 million pixels to play with, images from the A77 look excellent alongside those from its lower-resolution competitors when printed out or viewed on screen.
As the nominal successor to the A700, the SLT-A77 had a lot to live up to in terms of ergonomics and handling. Users of the A700 have been waiting for a long time now for Sony to release an APS-C format DSLR-styled camera which could compete with the much-loved A700 and on the whole, we think that the A77 fills this role admirably. Like the A700, the A77 is peppered with control points, but doesn't feel confusing or cluttered. It's heavy without being a lump, but a substantial hand grip and generous rubber coating on the front and rear lend it a reassuring 'quality' feel.
Unlike many previous (and some current) Alpha DSLRs, the A77's controls are well laid out, and fall readily to hand when shooting. The only real frustration is a slight UI 'lag' when activating the menu and changing key menu options and shooting settings. When shooting, it is disorientating to find that it takes the top and rear LCD displays a fraction of a second to 'catch up' with control inputs.
Of course the key difference between the A77 and Sony's Alpha DSLRs is its full-time live view system, and as we've already stressed at several points in this review, the system works extremely well. Sony's engineers knew that when creating an SLT successor to the A700 they would need to incorporate an EVF which was at least a match for the cosily familiar optical finder of more conventional high-end Alpha DSLRs. With the A77's 2.4 million-dot OLED EVF they have done exactly that. The A55's EVF was extremely good, but the A77's is a revelation. Quite apart from the crispness and detail of the live view image (which is excellent), the mere fact that shooting data, gridlines and a level gauge can be overlaid in the finder, plus of course 'live' exposure simulation make it inherently more useful in many respects than even the best optical design. What the EVF can't do, sadly, is maintain a 'real time' view during continuous capture at the A77's highest framerates of 8 and 12fps.
The Final Word
The Sony Alpha SLT-A77 is on the whole, a very enjoyable camera to shoot with. It offers an appealing combination of high-technology and good old-fashioned manual control, with a smattering of useful automatic modes, like Sweep Panorama and DRO+ which we really enjoy using. Despite the massive size of the A77's files it is the fastest large-sensor interchangeable lens camera currently on the market, but even if you don't see much value in its headline framerates, you'll appreciate the fast AF and responsive shutter in normal use.
The A77 is a worthy successor to the A700, but it isn't perfect. We're disappointed by the camera's JPEG rendering, and although it won't bother 'actual pixels' obsessives, if you want to make the most of the camera's exceptional pixel count you will need to shoot in raw mode. Even with the camera's parameters tweaked, though, the A77's JPEGs simply don't contain 24 million pixels' worth of detail - something that is painfully obvious towards the top end of its ISO sensitivity range.
If the A77's high framerates interest you, don't expect to get the same sort of performance as you might from a dedicated 'pro' sports camera like the Canon EOS 1D IV (or upcoming 1D X) or Nikon D3S. The A77's AF system is very good, but it can't keep up with erratic fast-moving subjects reliably at its fastest framerates, and you'll need to use an (expensive) UHS-I SDHC memory card to get the best buffering performance.
Overall though, if you're an existing Alpha SLT or DSLR user itching to upgrade, we can't think of any reason not to recommend the A77. Is the A77 good enough to change systems for? Maybe, but as always that depends on your priorities. The A77's fast capture modes are interesting, but not a panacea for successful sports and action photography. A 60p movie mode will excite some video pros very much, but others might bemoan the fiddly manual exposure options and feature incompatibilities that are part and parcel of shooting movies with the A77.
We're pretty confident though that whatever your level of expectations and expertise, the A77's rugged and well thought-out ergonomics, innovative full-time live view and AF systems and exceptionally good EVF will keep you very happy indeed. However, the somewhat mushy JPEG image quality, high noise levels and slightly laggy operation stop the A77 from getting a gold award.
Ergonomics & handling
Metering & focus accuracy
Image quality (raw)
Image quality (jpeg)
Low light / high ISO performance
Viewfinder / screen rating
Movie / video mode
Everyday stills and video work in a wide range of situations, and casual sports and action photography.
Not so good for
High ISO available light photography, and 'serious' sports and action work.
The A77 is a well-designed camera which spans the mid-range and semi-professional categories. Its headline features - high pixel count and blazingly fast continuous shooting - will attract a lot of interest, but of greater utility in day to day use are its effective ergonomics, reliable systems and excellent full-time live view system and full-time AF.
Scoring is relative only to the other cameras in the same category.
Click here to learn about the changes to our scoring system and what these numbers mean.