Slimline

Available in blue, pink, silver, black and brown, Sony's Cyber-shot DSC-T90 is the latest in a series of slim, stylish digicams designed for snapshooters. Equipped with a 12.1-megapixel CCD sensor and Carl Zeiss Vario-Tessar 4x optical zoom lens, its key features are its ultra-thin body, 3-inch LCD touchscreen and  ability to record 1280x720 pixel 720p HD movie clips with stereo sound. Super SteadyShot optical image stabilisation is also provided.


Colour options for the Sony Cyber-shot DSC-T90. (Source: Sony.)

The T90's metal body is typical of the T-series and solidly made with a slide-down lens cover that doubles as an on/off switch.  Styling is similar to its predecessor, the DSC-T77, albeit with some minor cosmetic changes. Like earlier models, the T90 is a scaled-down version of a more sophisticated model, in this case, the T900, which has a larger, higher-resolution touchscreen but is otherwise similarly featured.

As in other T-series models, the lens, flash, recording microphone and LED lamp used for the  self-timer/smile shutter indicator and AF illumination are tucked in behind the face plate when the camera is stored. Folded optics are used for the lens design, accounting for its small size and relatively slow maximum aperture range of f/3.5 to f/4.6.


Front view of the Cyber-shot DSC-T90 in brown with the lens and flash uncovered. (Source: Sony.)

Most of the rear panel is covered by the 3-inch LCD touchscreen, which has a 16:9 aspect ratio to cater for the camera's HD video capabilities - and also for the two 16:9 still shooting settings (one high-resolution and one for TV playback). The camera also provides a single high-resolution 3:2 aspect ratio option, along with five image sizes in 4:3 aspect ratio. Only the 16:9 aspect covers the entire screen; the other aspects have black bars along each side of the image frame.

Photo Review has never been a fan of touchscreens for setting camera controls and the 230,000-dot display on the T90 does little to change our opinion. Although you can make adjustments with either the stylus supplied with the camera or the tip of a fingernail, getting a feel for the amount of pressure required on the review camera's display was frustrating. There were times when a setting activated with the mere brush of a fingertip and others where we had to give a solid poke to effect the change. ‘Seizing the moment' to take a critical shot is difficult in such situations.


Rear view of the Cyber-shot DSC-T90 in brown showing the large LCD touchscreen. (Source: Sony.)

The touchscreen leaves no room for viewfinder or arrow pad so it has to be used for all adjustments. However, as in previous touchscreen Cyber-shots, the T90 lets you focus on a specific point in the frame. You simply compose the shot and touch the focus point. You can move the AF point several times before locking it in by half-pressing the shutter and taking the shot.

The top panel is sparsely populated with only a shutter button on/off power button and tiny zoom lever.  All of them are so small you need a fingertip to use them and they're likely to present problems for anyone with large fingers or limited dexterity.

The base panel carries the battery/card compartment, an off-centre, metal-lined tripod socket and a socket for the supplied Type 1a multi-connector, which handles AV-out, SD/HD component video, USB and DC-in connections. Interestingly, there's no direct HDMI output port but you can play back images and video clips on an HD TV set via an optional HD Output Adapter Cable.


The top panel of the Cyber-shot DSC-T90, showing the three controls plus the wrist strap lug on the side panel. (Source: Sony.)

Since the body of the T90 shows no evidence of mouldings or grip plates apart from the raised ridge of the strap lug, users may be hard-pressed to find a satisfactory way to hold this camera. It's possible to use the T90 one-handed by positioning it between the thumb and first two fingers of your right hand. The second finger steadies the camera while the pointer triggers the shutter and operates the zoom lever.


Shooting one-handed with the T90. (Source: Sony.)

Holding the camera with both hands provides greater stability - which is useful as the small size of the camera makes it difficult to hold rock-steady. However, it's deceptively easy to partly cover the lens with one or more fingers on your left hand.

Regardless of how the camera is held, you will inevitably find the screen covered with fingermarks. The shiny front panel also attracts smears, making this a camera that requires constant wiping. The casing is also vulnerable to damage from chemicals in sunscreens, insect repellents and wiper cloths.

Another feature requiring care is the sliding front panel, which doesn't fit quite tightly enough to prevent ingress of dust and grit. This isn't a camera to use in dusty conditions if you want to keep the coloured body panels scratch-free.

Features and Controls
Taking pictures with the T90 is mostly straightforward - particularly in the full-auto Easy Shooting mode, which enlarges the size of the on-screen text for better visibility. However the number of settings users can adjust is restricted to the self-timer, image size and flash modes. To access the full suite of adjustable controls, users must choose the Program Auto (PGM) mode.

In PGM mode, users can adjust ISO, white balance, AF and metering patterns and exposure compensation. Flash output is adjustable across three levels: minus, standard and plus (although there's no indication of how large the EV steps are).  You can also choose from three Dynamic Range Optimiser settings: off, standard and plus. Four Colour Mode settings can also be used: Normal, Vivid, Sepia and B&W.


The normal control display in PGM mode with the grid overlay selected.

Steady Shot stabilisation can be switched on and off and you can choose between two and ten second delays for the self-timer. In addition to single-frame and continuous shooting modes, the drive sub-menu has options for bracketing in +/-0.3, 0.7 and 1.0 EV increments. 

The shutter button on the review camera had an easily-detected half-pressed point that indicates when focus and exposure have been set with a soft beep. AF points are displayed in green brackets on the touchscreen to show where focusing is set. The zoom lever, while small, moves easily but it's difficult to zoom with high precision, despite the magnification figures that appear on-screen as the lever is moved. Zooming speeds are, however, moderate.


Image size settings.

Sony has equipped the T90 with a fair amount of technology to make it easier for novice users to shoot focused and correctly-exposed pictures. For starters, there's Double Anti-Blur stabilisation that combines two key technologies, High Sensitivity and Optical Steadyshot, to minimise the risk of motion blurring and camera shake. Add in an ‘intelligent Auto' (iAuto) mode with scene recognition that analyses the scene and will automatically set the correct shooting parameters from eight scene presets for point-and-press ease.

In all, there are 11 scene pre-sets to choose from, including an underwater mode for use when the camera is in a waterproof housing. In addition, face recognition and smile shutter technologies are provided for better portrait shots, the former setting exposure and focus on the basis of detected human faces, while the latter triggers the shutter in response to a detected smile.

When you don't know which shooting mode to select, an Advanced mode in the iAuto sub-menu causes the camera to take two shots, varying certain settings between shots, as shown in the table below:

The adjustments in the PGM mode are pretty standard for a point-and-press digicam. ISO settings range from a low of 80 to a maximum of 3200 and there's a generous suite of white balance presets (including three fluorescent light settings and two underwater modes).

Flash modes include Slow Synch flash for fill-in with backlit and low-light subjects and you can adjust flash output across three steps: minus, standard and plus (EV levels are not provided). Red-eye reduction pre-flash can be applied in any flash mode via a separate menu entry, which contains three settings: auto, on and off.

Pressing the Display icon on the touchscreen lets you choose between the default ‘Normal' display, in which shooting data are overlaid on the image field and a ‘Simple' display  with only the menu icons on-screen. There's also an Image Only option that eliminates the icons. The Display menu also contains icons for overlaying a small brightness histogram on the screen plus a screen brightness adjustment icon. A grid overlay guide is available via the setup menu.


The Display menu.

If you want to re-format a memory card (which should be done regularly) you must touch the Home icon and select the Manage Memory sub-menu (indicated by a Memory Stick icon). As well as providing formatting tools for both internal and card-based memory, this sub-menu will let you create, change and delete folders and copy image files between the internal memory and a memory card. You can also set the file numbering protocol.


The Manage Memory sub-menu.

Sensor and Image Processing
There appears to be nothing special about the CCD sensor used in the T90. However, it paves the way for the next-generation TX1 Cybershot, which was announced shortly after we commenced this review and features a new 1/2.4-inch (5.92 x 4.57 mm) Exmor-R CMOS sensor with 10-megapixel resolution. We hope to be able to review this camera when it's released in mid-September.

Despite being a conventional primary colour filter CCD chip, the 6.16 x 4.62 mm imager on the T90 has 12.4 million photosites and supports an effective resolution of 12.1 megapixels, which will be more than adequate for any potential user of this camera. Eight JPEG image sizes are supported but users have no control over compression levels. Typical image sizes are shown in the table below.

Video recording is accessed by touching the REC Mode button and selecting the Movie Mode icon (which resembles a film strip). The T90 has three movie modes, two covering 720p HD clips, which have a 16:9 aspect ratio and the other for VGA clips at 4:3 aspect ratio. The two HD modes are differentiated by bit rate. Typical recording times for a 2GB card are shown in the table below.

Continuous shooting is limited to approximately 29 minutes per clip, varying slightly with ambient temperature and the speed of the card used. Memory Stick Pro Duo cards are required for 720p video recording but not for VGA clips.

Playback
Image and video playback are accessed by pressing the dedicated button just above the right hand end of the touchscreen. Playback options are pretty standard with12-shot index thumbnails plus date, event and folder views. Individual shots can be displayed with or without shooting data and histogram overlaid and you can zoom in on selected areas in shots by touching the area you wish to enlarge. Up to 8x magnification is supported in this mode and arrows on the screen allow you to scan around the image.


Playback display with basic shooting data and histogram.

Dedicated icons are provided to initiate image rotation, toggling from one shot to the next, deleting image files and playing slideshows. Background music is available for the latter and you can upload your own music to the camera via the supplied Music Transfer software. You can filter playback to show only shots containing faces - or children, infants or smiles. Images can also be tagged as Favourites - or untagged.

Pressing the Menu icon in playback mode also lets you trim and resize images as well as apply post-capture red-eye correction, unsharp masking and soft focus, partial colour and fish-eye effects. Cross filter, radial blur and retro effect processing are also available and you can emphasise a smile by turning the corners of the mouth up with the Happy Faces mode.


Post-capture editing options.


The first page of the Stamps.

If you access the Paint function you can draw on images with the stylus or add ‘stamps' and frames and then re-size the image and save it separately. Images can also be protected and DPOF-tagged for automated printing. PictBridge support is included for direct printing. 

Performance
Still pictures taken with the test camera were bright and colourful, although out-of-the-camera images were slightly soft. This could have been due to Sony's new Clear RAW NR noise reduction system and the tendency of the camera to keep the ISO below 400 in the Easy and iAuto modes.

Test shots also showed the characteristic blown-out highlights we often find with small-sensor digicams. Exposures were biased slightly in favour of shadows and the in-camera dynamic range adjustment made no apparent contribution to suppressing over-bright areas and only minimal brightening to shadow reproduction.

Imatest showed the test camera's resolution to be slightly below expectations for the sensor's resolution and edge softening was evident in both Imatest analysis and many test shots. A small degree of barrel distortion was visible at wider angles of view but this had been corrected by about mid-way along the zoom range. The graph below plots the results of our tests at four focal length settings.



Resolution began to decline at ISO 800 and was very low at ISO 3200, where noise was also obvious. Unlike some digicams, the T90 maintains full resolution right up to the highest ISO setting. The graph below shows the results of our Imatest test across the T90's sensitivity range.



Lateral chromatic aberration ranged from low to moderate through the zoom range and coloured fringes were evident both at the edges and towards the centre of many shots taken in bright outdoor lighting. Imatest showed colour accuracy to be generally good, although saturation was slightly elevated in the red sector of the spectrum.

The flash required ISO 800 to illuminate an average-sized room but tended to over-expose with close-ups at high ISO settings. Image noise became visible in flash shots at ISO 800, although you would still be able to print shots taken at this setting at snapshot size. Long exposures were noise-affected at ISO 800 and shots taken at ISO 3200 looked blotchy and unsharp. 

Close-up performance was generally good and the Magnifying Glass mode provided some excellent ultra-close pictures. However, the image stabilisation system wasn't always effective in this mode and we estimate roughly 60% of shots taken were slightly unsharp. It was also impossible to obtain completely out-of-focus backgrounds in close-up shots taken in the normal macro mode.

Digital zoom shots taken with the camera set at its highest resolution were crisp and clean and relatively free of processing artefacts. In contre-jour lighting - and when subjects were photographed against a bright background, the lens was more affected by veiling flare than we expected. However, an adequate contrast range was recorded with subjects that were only mildly backlit.

Auto white balance performance was similar to many other digicams. Although shots taken under fluorescent lighting showed a barely discernible green cast, shots taken in incandescent lighting were noticeably orange-biased. None of the pre-sets produced neutral colour rendition, although they came close enough to require fairly small adjustments in editing software.

Video quality was acceptable for such a tiny camera, although nowhere near the quality of the video we obtained with the Panasonic FT1 (which is also pocketable).  Some degree of frame cropping is applied in video mode, changing the effective focal length range for HD 702p clips to the equivalent of 38-152mm in 35mm format and VGA clips to 46-184mm. Audio quality was tolerable but uninspiring.

The test camera powered up in just over 1.5 seconds and we measured an average capture lag of 0.2 seconds, which was eliminated with pre-focusing. It took approximately 3.6 seconds to process each high-resolution JPEG. Shot-to-shot times averaged a little less than four seconds. In the continuous shooting mode, the test camera recorded shots at half-second intervals (which equates to two frames/second). Processing appeared to be on-the-fly as it took 4.7 seconds to process a burst of seven shots. 

Buy this camera if:
- You're looking for a small, ultra-slim snapshot camera.
- You're happy to use the monitor for shot composition and can work with touchscreen controls.
- You'd enjoy some of the post-capture, in-camera editing functions.
- You want to shoot widescreen high-definition video clips

Don't buy this camera if:
- You need a camera for use in dusty or humid conditions.
- You want to shoot raw files. (The T90 is JPEG only).
- You require Full HD video functionality.


IMATEST GRAPHS

SAMPLE IMAGES

Auto white balance with incandescent lighting.

 
Auto white balance with fluorescent lighting.

Close-up: 6.2mm focal length, ISO 100, 1/50 second at f/3.5.


Close-up in zoom mode: 24.7mm focal length, ISO 80, 1/250 second at f/5.6.

Magnifying Glass mode: 6.2mm focal length, ISO 100, 1/100 second at f/3.5.

Magnifying Glass mode: 6.2mm focal length, ISO 100, 1/650 second at f/3.5.


Night exposure at ISO 80: 11.9mm focal length, ISO 80, 1/2 second at f/3.5.


Night exposure at ISO 3200: 11.9mm focal length, ISO 3200, 1/50 second at f/3.5.

Flash exposure at ISO 100: 11.6mm focal length, 1/40 second at f/4.

 
Flash exposure at ISO 3200: 11.6mm focal length, 1/40 second at f/4.

6.2mm focal length, ISO 80, 1/400 second at f/4.5.

24.7mm focal length, ISO 80, 1/400 second at f/7.1.

6.2mm focal length, ISO 80, 1/640 second at f/5.6.


Crop from the above image at 100% enlargement showing coloured fringing.


Mild backlighting. 11.6mm focal length, ISO 80, 1/250 second at f/4.5.


Strong backlighting: 6.2mm focal length, ISO 80, 1/500 second at f/5.6.


Strong backlighting: 24.7mm focal length, ISO 80, 1/160 second at f/4.6.

The above images are still frames from video clips, showing wide-angle and zoomed-in views plus an example of artefacts in the video clip.

Image sensor: 6.16 x 4.62 mm CCD with 12.4 million photosites (12.1 megapixels effective)
Lens:  Carl Zeiss Vario-Tessar 6.18-24.7mm f/3.5-4.6 zoom lens (35-140mm in 35mm format)
Zoom ratio: 4x optical, approx. 8x digital
Image formats: Stills - JPEG; Movies -MPEG4
Image Sizes: Stills - 4000 x 3000, 3264 x 2448, 2592 x 1944, 2048 x 1536, 640 x 480; 4000 x 2672, 400 x 2248, 1920 x 1080; Movies - 1280 x 720, 640 x 480, both at 30 fps
Shutter speed range: 1/1000 second to 2 seconds
Self-timer: 2 or 10 second delay
Image Stabilisation: Optical Steady Shot
Exposure Compensation: +/- 2EV in 1/3EV steps
Focus system/range: TTL AF; range 8 cm to infinity; macro to 1 cm
Exposure metering/control: Multi-Pattern, Centre-weighted, Spot metering
Shooting modes: Intelligent Auto, Easy Shooting, Program Auto, Smile Shutter, Scene Selection (Twilight, Twilight Portrait, Landscape, Soft Snap, Snow, Beach, Fireworks, High Speed Shutter, High Sensitivity, Underwater, Gourmet)
ISO range: Auto, ISO 80, 100, 200, 400, 800, 1600, 3200
White balance: Auto, Daylight, Cloudy, Fluorescent (x3), Incandescent, Flash, Underwater (x2)
Flash modes/range (ISO auto): Auto, Flash On, Flash Off, Slow Synchro (red-eye reduction is available); range: 0.8-2.9 metres (ISO  auto)
Sequence shooting:  1.8 frames/second for up to 100 shots
Storage Media: 11MB internal memory plus Memory Stick Duo expansion slot
Viewfinder: no
LCD monitor: 3-inch Clear Photo Plus Touch Screen with 230,000 pixels
Power supply: NP-BD1 rechargeable  lithium-ion battery; CIPA rated for approx. 220 shots/charge 
Dimensions (wxhxd): 93.6 x 57.2 x 15.0 mm
Weight: Approx. 128 grams (without battery and card)