Sony SLT-A35 Review
The SLT-series' translucent mirror design and full-time live view make it easier to implement a video mode than it would be on a 'traditional' DSLR, which needs to flip its mirror out of the way before it can start recording. It also means that the SLT-cameras can use the phase-detect AF sensor where 'traditional' SLRs and interchangeable lens cameras have to make do with the slower contrast detect systems.
Like previous SLT-models the A35 offers 1080i video in AVCHD format (which offers excellent quality with efficient compression and is most suitable for viewing on a HD television set) or 1440 x 1080 pixels in the less efficient but more readily sharable MPEG-4 format. Despite the pixel count the MP4 video is still captured in the 16:9 aspect ratio and is usually interpolated up to 1920x1080 when played back so doesn't appear stretched or squashed.
The A35's, compared to the A55, redesigned 16MP sensor brings an important change for video shooters with it. The new sensor should not only improve the camera's battery life but also offer improved heat characteristics - extending the duration of video clips the camera can capture before any risk of overheating occurs. The A35 can shoot for 29 minutes per shot, rather than the 9 that the A55 can manage with SteadyShot switched on (most DSLRs are limited to 29 minutes or fewer for reasons of heat build-up or to avoid attracting duty at the higher rate applied to camcorders).
A second important difference in terms of video shooting is the lack of a tilting screen. While on the A55 the screen could be flipped upwards to shoot video holding the camera at chest or waist-level, on the A35 this is not possible and you'll have to hold the camera fairly high up to see what's going on on the screen. For video shooters this posture is not ideal. Thirdly, the new A35's new Picture Effects can not only be applied to stills images but also to video footage. For those who find it problematic to hold their camera straight while shooting video we should also mention that the A35 does not come with the A55's digital level gauge feature.
In AVCHD mode the A35 offers high quality HD video capture at 1920 x 1080 pixels (1080p) at 25/30 frames per second (depending on whether your camera is a PAL or NTSC model), though the files are doubled up to 1080 i at 50/60 fps for HDTV compatibility. If you record your videos in MPEG-4 format you can also choose a smaller VGA video size.
The built-in microphone captures stereo audio but you can also connect an optional external stereo microphone to provide greater directionality and isolation from lens noise. There is a small built-in speaker for video playback in-camera.
1920 x 1080, 1080i (60/50fps), Av. 17Mbps
1440 x 1080, 1080p (30/25fps), Av. 12Mbps
640 x 480 (30/25fps)
|Audio||• Dolby Digital Audio
• Stereo audio capture via optional external mic.
|Format||AVCHD / MPEG4|
|File size||2.43 MB/sec (1080i AVCHD), 1.65 MB/sec (1440 x 1080 MPEG4))|
|Max file size per clip||2.0 GB for Motion JPEG, card capacity for AVCHD (new file is created automatically after file size has reached 2.0 GB)|
|Recordable time||Approx 29 minutes|
Using Movie Mode
Capturing a movie on the Sony SLT-A35 works in a very similar way to previous SLT models. You press the red movie button to start and stop recording. The camera's movie mode lacks manual control over shutter speed and aperture (if you shoot with manual focus you can set the aperture before you start recording) but nevertheless still offers some scope for creative control. You can apply exposure compensation while creative styles, white balance, AF area and metering mode are all taken over from the current stills image settings.
You'll have to turn the mode dial to the SCN/Picture Effects position to apply the new new Picture Effects to your video footage. In the camera's shooting menu there are only three movie options to be found - you can select the recording format and size and deactivate audio recording.
The autofocus is set to continuous but of course you can focus manually if you wish. If in 'Local' AF mode you can change the AF area while shooting. Due to having its phase-detect AF available at all times, the A35 focuses faster than DSLRs that rely on a contrast detect system. But, because of the shallow depth-of-field offered by large sensor cameras (and depending on the subject) shooting video with AF is not always recommendable. Firstly the camera doesn't always focus on the right subject which can lead to visually unpleasant 'focus jumps' and secondly the noise of the focus motor can be heard on the audio track. Although the latter can be avoided by using an external microphone, due to the narrow depth-of-field of an APS-C sensor camera, even small shifts in focus will be much more visible than on small-sensor camcorders or compact cameras.
Movie mode displays
|There are only three movie options in the menu: you can set movie format and size and switch audio recording off.||The movie screens look much like the regular shooting modes but are using the entire 16:9 aspect ratio of the screen. There are also two display modes with a reduced amount of shooting info.|
Video quality comments
The Sony SLT A35's sensor is APS-C size and therefore you can't quite create the same depth of field effects as on a full-frame-camera such as the Canon EOS 5D Mark II but you still get a much shallower, more cinematic depth of field (and much better image quality) than most camcorders or any digital compact camera. The videos are screen-filling and the level of detail and smoothness are pretty much in line with other cameras of this level. In low light some chroma noise and grain become visible but this is well within acceptable limits.
Continuous is the default AF mode when shooting video (single is not available). It is generally pretty good but there are some occasional focus shifts and the AF can, despite the translucent mirror, struggle to follow fast-moving subjects. Sometimes the focus motor can also be heard in the audio recording and we would therefore recommend using manual AF as an alternative.
The built-in mic is pretty sensitive and though the sound quality is perfectly acceptable it's not directional enough, and tends to pick up camera operation noises including the image stabilization. For serious use an external microphone is the better option.
Like pretty much all other video-capable cameras with a CMOS sensor the SLT-A35 suffers from distortion caused by its rolling shutter. The readout of the sensor means horizontal lines of the image are scanned, one after another, rather than the whole scene being grabbed in one go. The upshot is that verticals can be skewed if the camera (or the subject) moves too fast - the top of the image has been recorded earlier than the bottom, so vertical lines can be rendered as diagonals. During very quick panning the effect is clearly noticeable on the A35 but at 'normal' panning speeds the effect is hardly noticeable and should not have an impact on your video work.
Overall the A35's video mode delivers output that is pretty much indistinguishable from the A55's. The image quality is good and in line with other models in this bracket of the market, but the lack of manual control makes the A35 less attractive for serious videographers. Below you'll find examples of videos taken with the camera for you to download and draw your own conclusions.
Caution: very large files
Sample video 1 - Outdoors, good light
|1920 x 1080, AVCHD, .MTS file, 15 sec. 31.1 MB Click here to download the original .MTS file|
Sample video 2 - Indoors, moderately low light
|1920 x 1080, AVCHD, .MTS file, 13 sec. 32.7 MB Click here to download the original .MTS file|