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Performance

Overall Performance

At its price point the Sony SLT-A65 is a very well specified camera, with ergonomics and operational speed to match. The maximum frame rates in continuous shooting and AF speed in live view are class leading, the only area that merits some small criticism is the responsiveness of the user interface. The user interface of the first SLT-A65 that arrived in our office suffered from a distinct 'lagginess' that we had not seen in a long time on a digital camera.

When quickly browsing the menu or other parts of the user interface the 'cursor' would sometimes need a fraction of a second to catch up with the user's button clicks. This lagginess has been very much reduced with the installation of firmware v1.03 but still hasn't been totally eliminated. That said, it's now only really noticeable when you're moving through the UI very quickly, for example when trying to find a setting in the menu the exact location of which you cannot remember or when doing repetitive tasks that require frequent change of settings (such as shooting test charts in a studio).

When you talk about the A65's performance, you have to mention its maximum frame rate. The SLT-series' unique design with fixed mirrors and the integration of a phase-detection AF sensor in the top of the mirrorbox rather than the base allow for an exceptional maximum frame rate of 10 fps. However, this comes with some limitations (as you can read in more detail below), and don't be mislead by the shooting rate alone - the A65 cannot compete with dedicated sports cameras such as the Canon EOS 1D Mark IV or the Nikon D3s.

Continuous Shooting and Buffering

The SLT-A65 has three continuous shooting modes, 'Lo','Hi' and 'Continuous Advance Priority AE'. In continuous 'Lo' mode the A65's nominal frame rate is 3fps, which increases to 8fps in 'Hi' and 10fps in 'Continuous Advance Priority AE' mode.

The 'AE' in Continuous Advance Priority AE mode stands for 'automatic exposure'. Unlike continuous Lo and Hi, Continuous Advance Priority AE can only be accessed via the exposure mode dial. As we saw in the A55, which offered a maximum frame rate of 10fps in the same mode, there are some downsides to this maximum capture rate. The A65 can still autofocus continuously, but in order to be able to do this, aperture is either fixed wide open, or limited to f/3.5 if the maximum aperture allows it. You can take full control over aperture in Continuous Advance Priority AE mode, but only if you select AF-A or manual focus. The reason for this limitation is the same reason why you cannot combine AF with manual aperture control in movie mode - at apertures smaller than f/5.6 the A65's AF system receives essentially no light, so cannot function.


Another disadvantage of the SLT system when it comes to fast shooting is that it isn't possible for the A65 to maintain a live view feed in its fastest 8fps and 10fps continuous capture modes. The viewfinder does not black out when shooting at these high frame rates, but shows a sequence of still frames in real time. What this means is that at any given moment, you don't see the view through the camera's lens right now, but how it was a fraction of a second ago. This makes little or no difference if you're shooting slow-moving or static subjects, but it makes panning with fast-moving subjects very hard indeed, since you never know where they are - only where they were.

Continuous Advance Priority AE

Timing
JPEG Large/Fine
RAW
RAW+JPEG Fine
Frame rate 10.0 fps 10.0 fps 10.0 fps
Number of frames 11 14 13
Buffer full rate 2.4 fps 0.7 fps 0.6 fps
Write complete 9 sec 19 sec 24 sec

Continuous Hi

Timing
JPEG Large/Fine
RAW
RAW+JPEG Fine
Frame rate 8.0 fps 8.0 fps 8.0 fps
Number of frames 19 14 13
Buffer full rate 2.1 fps 0.7 fps 0.5 fps
Write complete 8 sec 20 sec 24 sec

Continuous Lo

Timing
JPEG Large/Fine
RAW
RAW+JPEG Fine
Frame rate 3.0 fps 3.0 fps 3.0 fps
Number of frames 42 17 14
Buffer full rate 2.3 fps 0.7 fps 0.5 fps
Write complete 9 sec 20 sec 25 sec

All timings performed using a 16GB SanDisk Extreme Pro UHS-I SDHC card (45MB/s)

One of our biggest criticisms of the original SLT-A55 was its lengthy buffer times after shooting continuous bursts of images - up to around 50 seconds depending on the file type. As you can see, with our current UHS-I SDHC test memory card, the A65 performs much better. However, a wait of up to around 25 sec can still seem quite long when you're out in the field, desperately waiting for your camera to be ready for the next burst while your subject is disappearing into the bushes.

In comparison to its bigger sister model, the A77, where a fast memory card can make a real difference, the A65 is slower to push the huge 24MP image files through its data-pipeline and therefore the use of a really fast card is not as advantageous as on the A77. The numbers in the table above were measured on a 16GB SanDisk Extreme Pro UHS-I SDHC card - one of the fastest and most expensive cards currently available. On a more standard card, such as SanDisk's Extreme III Class 6 SDHC card, the camera's performance slows down, but stays within acceptable limits.

In continuous Hi shooting the number of frames in a burst decreases to 17 and the write complete time increases to 11 sec. In RAW mode you still get 14 frames in a burst, but the write time increases to 22sec. All in all though, for most users the difference is probably too small to justify the investment in a UHS-I card.

Autofocus speed / accuracy

The AF system is one of the camera components that Sony uses to differentiate the flagship SLT-A77 from the more affordable A65. While the SLT-A77 uses an all-new 19-point AF system the A65 comes with the tried and tested 15-point array that we first saw in the original SLT-A55.

When photographing static subjects we found the system very fast and accurate and we could hardly find any out-of-focus images amongst our several hundred sample shots. Unfortunately, the story is a little different when focusing on fast-moving subjects. Despite the A65's translucent mirror technology - the mirror is fixed, meaning the AF sensor can operate full-time, without interruption - we have found that when presented with fast moving subjects focus accuracy is far from 100%. In 10fps mode it is clear that the A65's AF system is simply unable to predict subject position accurately when presented with fast-moving subjects at relatively close range. Whilst the zone of focus shifts from frame to frame, it is almost always slightly behind the intended subject.

The conclusion has to be that for everyday use, the A65's AF is perfectly capable, and very good for its class. However, while the A65's impressive continuous shooting specs may suggest it to be an ideal tool for sports and action photography, in demanding shooting situations the AF system cannot always quite keep up.

Image Stabilization

The A65's SteadyShot INSIDE sensor-based image stabilization system is the same as in the SLT-A77. It's the latest incarnation of a very well-established technology introduced by Konica-Minolta, long before Sony took over the brand and began making its own DSLRs. This is a long way of saying that it is tried and tested and in our time with the camera we have found it to be reliable and useful.

Sony claims that SteadyShot INSIDE offers a benefit of between 2 and 4 stops, and our testing backs this up. In normal use we would expect to reliably get around three stops (allowing you to shoot with a 100mm lens at around 1/30sec, for example, assuming only moderate camera shake). Naturally, it also works with every lens you can put onto the camera, including those which don't have optically-stabilized equivalents in the Canon and Nikon systems (such as wideangles and fast primes).

Battery life

Despite the A65's rather battery-hungry technologies such as full-time live view and sensor-based image stabilization, battery life is decent and approximately in line with Sony's own CIPA measurements (510 images in live view mode or 560 using the EVF). During our real-life tests we got approximately those numbers out of the camera, with some video shooting and image reviewing included.

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bondarensa

shot with this camera, incl. Scene Mode "Sunset" with no post processing:
http://fotki.yandex.ru/users/bondarensa/view/711411/?page=0

1 upvote