The image above was taken with the Sony Alpha SLT-A77 with the 16-50mm F2.8 kit lens. The lens was set to its maximum wide angle position at 16mm to provide an equivalent field of view to the 15-85mm f3.5-5.6 kit lens on the Canon EOS 7D. With an Aperture of f5.6 the camera metered an exposure of 1/1600 at 100 ISO. The original Extra fine JPEG image size was 16.78MB. The crops are taken from the areas marked with red rectangles and presented here at 100%.

For this tripod-mounted test stabilisation was disabled. Contrast enhancement on both cameras was left on the default settings – auto DRO on the SLT-A77 and Standard Auto Lighting Optimizer on the EOS 7D. The SLT-A77’s lens correction was also left on the default – shading and chromatic aberration set to auto and distortion correction off. The EOS 7D metred a slightly longer exposure for this scene so I set exposure compensation of -1EV to produce the same exposure as on the SLT-A77.

Overall, the SLT-A77’s 24.3 Megapixel sensor delivers contrasty, well saturated results at the best quality JPEG setting, though the white balance has the typical Sony blue bias. The level of detail is excellent and edge sharpness good, though the processing is a little softer than on some consumer DSLRs.

Looking at the crops individually, The top one shows good detail in the chapel but it lacks the hard edges and contrast of the NEX-7 for example. This softer approach to processing is also evident in the lighthouse crop. The lens is resolving a high level of detail and the sensor is recording it, but the SLT-77’s slightly less aggressive approach to processing provides a very natural looking result. The edge of the window frames in this crop are a little soft, but I’d be surpised if there wasn’t scope to produce a crisper result from the RAW files, or by adjusting the in-camera sharpness and contrast, if that’s what you prefer.

The third crop shows what the SAL 1650 SSM zoom can do in conjunction with the A-77’s lens correction firmware. There’s just the tiniest hint of a fringe down the edge of the drainpipe, but nothing you’d notice unless you were examining the image closely at 100 percent view. The edge detail is amost as well resolved here as in the centre of the image.

Which brings us to the final crop. Here again, the fine detail and edges are clearly picked out, but are not as punchy as they might be with more aggressive processing. But the detail is there with clear separation between the balcony rails and the scaffolding poles cleanly defined.

The Canon EOS 7D’s 18 Megapixel sensor produces smaller images than the SLT-A77 hence the larger crop area. Let’s first talk about the comparitive performance of the two lenses. The EF-S 15-85 IS USM is effectively the new kit lens for the 7D which is bundled with either this or the EF-S 18-135mm f3.5-5.6 IS. In my tests on the 7D with this lens, the biggest quality determinant was the edge-to edge performance with some quite noticeable softness and chromatic aberration at the edges of the frame. This is most clearly visible in crops one and three.

Comparing crops two and five with those from the Sony SLT-A77, aside from the white balance, the most obvious difference is the 7D’s more agressive processing which produces more crisply defined edge detail and a punchier overall result. This is most apparent in the final crop from the centre of the frame. If you compare the window frames, balcony dividers and scaffold poles it’s clear that the 7D is producing a crisper, punchier result with cleaner edges. As I said earlier though, this looks to be mainly down to different processing approaches and you could tweak the SLT-A77 results either in-camera or via the RAW file to achieve something similar. Check out the A77 RAW vs JPEG results on the next page or see how these models compare at higher sensitivities in the A77 Noise results.

Before I look at the individual crops just a word about in-camera JPEG compression on the SLT-A77. There are three JPEG quality/compression settings – Standard, Fine and Extra fine. The Fine setting produces files around 5-8MB in size and Extra fine JPEGs are around 10-16MB, so around half the compression is applied to Extra Fine JPEGs as Fine ones.

With the Camera set to RAW+JPEG, the JPEG files are compressed at the Fine quality, the only way to get Extra fine quality JPEGs is to shoot JPEG only. Of course, if you shoot RAW+JPEG you can process the file in Image Data Converter and apply less compression when you export it, which is what I’ve done for the RAW comparison here. The RAW file was processed using Image Data Converter’s default settings and exported at Compression Level 1 (High Quality) producing a JPEG file 20MB in size.

Glancing down the two columns of crops the overall impression is that the in-camera JPEGs are a little more processed than the RAW files. They’ve got a little bit more contrast, the edges are more sharply defined and it would be fair to describe them as more ‘consumer-friendly’ than the processed RAW file.

The top row shows much crisper detail from the in-camera JPEG than the crop from the RAW file processed with Image Data Converter using the default settings. And in fact all four crops from the RAW file look softer than the in-camera JPEG, but despite the enhanced sharpness and edge contrast in the JPEG crops they don’t look any noisier.

One other interesting thing is the chromatic aberration in the third crop. The in-camera JPEG has very marginal fringing, the processing has done an excellent job of minimising it, but it hasn’t eradicated it completely. There’s no trace of it in the RAW file though, so on shots where fringing is a problem processing the RAW file is an obvious solution. The second thing to note is there is a just visible halo along the chapel wall and horizon in the first crop. You’d never noitice it ordinarily and the halo is also visible in the Extra fine JPEG on the outdoor results page, but there’s no sign on it on the processed RAW file.

In fact it isn’t too difficult to match the in-camera results by tweaking the settings – reducing the noise reduction and increasing sharpness. I think Sony has adopted the right approach here, though. As with the NEX-7 it’s producing crisp, punchy ready to use out of camera JPEGs (though interestingly, not as crisp and punchy as NEX-7 JPEGs) with the option to go for a less or more processed look with the RAW files if you prefer..

Now let’s see how they compare at higher sensitivities in my A77 noise results.

The Alpha SLT-A77 inherits the Handheld Twilight mode from recent Sony cameras. This fires-off six frames in quick succession and stacks them into a single image in an attempt to lower noise levels.

On this page I’ve put the SLT-A77’s Handheld Twilight mode to the test. This automatically selects the sensitivity so I’ve compared it against the closest manual ISO.

You can see a set of results for the Multi-frame Noise Reduction option lower on this page.

The cameras were set to f5.6 in Aperture priority mode, the lenses were set to the same field of view and the ISO sensitivity was set manually.