Pentax enters the competitive super-zoom market with the X70, a 12-megapixel digicam with an advanced suit of controls and a 24x optical zoom lens. Covering a focal length range equivalent to 26-624mm in 35mm format, the lens boasts a fast f/2.8 maximum aperture at the widest position and the camera includes an ‘Intelligent Zoom' function that can extend magnification to 150x, providing an equivalent focal length of approximately 3900mm at VGA resolution. Sensor-shift image stabilisation and a 2.7-inch monitor are other key features.

Superficially, the X70 has the SLR-like styling that characterises the ultra-zoom models from Canon, Nikon, Olympus, Panasonic and Sony. It also shares many common features, including offering P, A, S and M shooting modes plus a range of Scene presets, along with built-in image stabilisation. Although just missing out on being the lightest model in the category, the X70 has the lowest RRP. A table comparing key features from the leading models can be found on the Photo Review website.

Build and Ergonomics
Aside from a thin metal ring on the lens barrel, the body of the X70 is made entirely of black plastic - right down to the tripod mount lining. It's one of the most compact and lightweight models in the ultra-zoom category and feels less substantial than some of the others we've reviewed. However, overall build quality is reasonably good with finish to match.


Angled front view of the Pentax X70 with lens extended. (Source: Pentax.)

The grip is rubber coated and there's a rubber thumb pad on the rear panel for added comfort and security. The large lens barrel extends 55 mm from the front panel, with inner barrels protruding a further 17 mm when the camera is powered-up and 60 mm at full zoom extension. A clip-over lens cap is provided with a tether that attaches it to the camera strap.


Rear view of the Pentax X70 showing the mode LCD and main button controls. (Source: Pentax.)


Top view of the Pentax X70 with lens extended.

The control layout is pretty conventional, with a prominent top-mounted mode dial, rear LCD monitor and arrow pad, along with dispersed buttons for accessing various functions. The housing for the electronic viewfinder (EVF) protrudes approximately 12 mm out from the LCD, minimising the chance your nose will touch the screen. The EVF eyepiece is rather cramped and its surround in hard plastic, which isn't good news for users who wear glasses. However, the 200,000-dot resolution of the display is marginally better than some other EVFs - and it displays all the shooting information.

The mode dial carries the standard Auto Picture, Scene, P, Tv, Av and M settings plus a User memory where you can store settings for the P, Tv, Av and M modes. It also contains a Movie mode setting plus a Digital Shake Reduction mode that boosts ISO sensitivity and therefore helps to reduce the effect of subject movement. The remaining Sport mode prioritises fast shutter speeds and also engages AF tracking.

Right of the mode dial is the exposure compensation button with the power switch behind it. The zoom lever surrounds the shutter button, while a button on the left side of the flash housing raises the flash, which only operates when popped up - even in Auto Picture mode.

The rear panel is dominated by the 2.7-inch LCD monitor, which has a relatively low resolution of 230,000 dots but is anti-reflection coated (although this doesn't help a lot when you're trying to use it in bright sunlight.

Above the screen are the EVF/LCD and Display buttons. Right of the Display button is the e-dial, which is used to change many camera settings. Below the e-dial is a button for engaging the face detection mode. The Playback button lies below it.

The arrow pad's directional buttons access the drive, focus and flash settings. The lower button is dedicated to the Capture Mode Palette and operates when the main mode dial is set to the Scene (SCN) mode. Pressing this button displays icons for each of the 20 scene presets, along with a brief text explanation of the purpose of the selected mode.

A central OK button in the arrow pad locks in each setting. Below the arrow pad are the Menu button and the Green button which, when pressed, switches the camera to full-auto operation. You can convert the Green button into a Function button that provides quick access to the resolution, quality, white balance and ISO settings.

Controls
Autofocusing is contrast-based and the X70 provides six focusing options: Standard, Macro, 1cm Macro, Infinity, Manual and AF Area Selection. The latter uses 25 selectable points and you must select the area you wish to focus on with the arrow pad before pressing the OK button to lock that selection in. Brackets on the screen show the selected area.


The 25-point array for AF point selection.

The X70's menu design is straightforward, with four pages of shooting functions and three pages in the Setting menu, which controls functions like date/time adjustment, folder naming, guide displays, USB and video connections, screen brightness adjustment and resetting and formatting controls. Users can choose between three Image Tone settings: Bright (the default), Natural and Monochrome.


The record menu on the X70 showing the three Image Tone options.

Pentax provides adequate adjustments for most functions. Shutter speeds range from a maximum of four seconds up to 1/4000 second, while sensitivity can be varied between ISO 100 and ISO 6400 in one-stop increments. The lens aperture range goes from f/2.8 to f/8 in 1/3 EV increments but has a maximum aperture of only f/5 at full zoom extension.

The Auto Picture mode implements scene recognition technology to set the most appropriate shooting mode for a given subject or scene by detecting the subject's lighting, movement and other conditions. Depending on scene parameters, the camera will choose from Landscape, Portrait, Night Scene, Night Scene Portrait, Flower, Sport and Standard modes or switch to macro mode is a close subject is detected.

Like its competitors, the X70 comes with built-in face detection AF and AE, which is capable of identifying up to 32 human faces in a frame in approximately 0.03 seconds. Blink detection and smile detection can be switched on or off in the camera's menu. When the Face Recognition function is engaged, an icon indicating either Face Priority On or Smile Capture is displayed on the monitor.

The X70 boasts three continuous shooting modes. The high-speed (H) mode can capture 21 shots at up to 11 frames/second, while the medium- (M) and low-speed (L) modes are restricted to seven frames at 6.3 fps or   four fps. In all three modes, image resolution is limited to five megapixels (2592 x 1944). 
Other noteworthy inclusions include an Interval Shooting mode, which allows a series of shots to be taken over a longer period of time. You can set  initial delay to ten seconds and then the shot-to-shot intervals between one second and four minutes or in one-minute intervals from four to 99 minutes for a maximum number of 1000 shots (depending on available memory). The start time for the recording can be delayed between one minute and 24 hours.

Pentax has adopted a ‘Triple Shake Reduction' system for the new camera. In addition to a CCD-shift stabiliser that uses gyro sensors to detect camera shake and shifts the sensor to compensate plus ISO-boosting via the Digital Shake Reduction mode, the X70 also has an electronic Movie SR function, which is used for video capture.

The X70 also supports auto bracketing, covering three shots at intervals of +/- 0.3 EV or +/- 0.2 EV (user selectable). An interesting Digital Wide function, accessed via the Scene menu, enables the camera to stitch together two sequential shots to produce a single frame with up to 20mm (35mm equivalent) coverage. In-camera panorama stitching is also available for up to three sequential frames.


The Digital Wide scene preset.


The Frame Composite  mode.

The camera also comes with a Frame Composite mode, which is also accessed via the Scene menu and four-way controller and lets users select a frame to surround the next shot taken. Nine different frames are displayed on the screen. Image size is fixed at 3M (2048 x 1536 pixels) in this mode.

Sensor and Image Processing
The 6.13 x 4.6 mm CCD sensor is the same-sized (1/2.33-inch) chip as used in the Nikon P90, Olympus SP-590UZ and Panasonic FZ28 and slightly larger than the sensor in the Sony HX1 but smaller than that in the Canon PowerShot SX10 IS. However, there's less than a millimetre difference in the overall dimensions, which would be more than compensated by the lower resolution of the Canon, Panasonic and Sony models.

Like most digicams, the X70 can only record JPEG images. However, it offers nine image size settings and three quality levels, which should be adequate for the majority of users. The table below shows typical file sizes for still images.

Movie clips are recorded in the standard AVI (Motion-JPEG) format with PCM monaural sound.  Pentax has been almost as generous with movie recording options, providing two aspect ratio settings and a choice of 30 or 15 fps frame rates. However, HD video at the top resolution of 1280x720 can only be recorded at 15 fps, while the other 16:9 format records 848 x 480-pixel clips at 30 fps.


The Movie record menu showing the array of resolutions and frame rates offered.

Both VGA and QVGA video clips in 4:3 aspect ratio can be recorded at either frame rate. Typical recording times for a 2GB memory card are shown in the table below.

You can use the optical zoom to set the focal length before starting to record but, once recording is in progress, only the digital zoom can be used. Maximum length for video clips is 2GB.

Playback
All the standard playback functions are supported, including single-frame (with and without data), index (four or nine thumbnails), folder and calendar displays. You can playback slideshows of stored images, resize, crop and rotate selected shots. In-camera rotation is also supported and selected shots can be deleted, protected or DPOF-tagged for automated printing.

You can add voice memos to still images and there appears to be no limit to the length of the sound bite, other than available memory. Pressing the Face Recognition button and play button simultaneously allows you to zoom in on faces in played images. Other post-capture editing functions include in-camera red-eye correction and the ability to apply the frames from the scene mode menu to captured image files. Digital filters provide a variety of post-capture adjustments, including B&W and sepia conversion and colour filtration in red, pink, purple, blue, green and yellow. Three colour extraction filters are also available: red, green and blue. Soft filter and fish-eye effects are also provided in the digital filters menu, along with brightness adjustment.

Performance
Test shots taken with the review camera appeared sharp and colourful and saturation was relatively modest with the default Bright setting, although a little subdued with the Natural setting. Dynamic range in test shots was wider than expected for a small-sensor digicam, although blown-out highlights were common in shots with an extended brightness range as metering tended to favour shadow detail.

Imatest showed the review camera's resolution to be up to expectations, with the highest resolution figures being obtained at around f/3.5. Edge softening was detected at all focal length settings we tested, with only a slight lessening as the aperture was closed down. (Examples can be seen in the Sample Images section below.) The graph below shows the results of Photo Review's tests.

Resolution was highest at ISO 500 and declined progressively as sensitivity levels were increased, with a significant drop at the ISO 3200 setting. This is to be expected since the camera defaults to 5M capture (2592 x 1944 pixels) at the two highest sensitivity settings. The graph below shows the results of our Imatest tests

Image noise became visible at ISO 400 in the long exposures we took at night and was quite obvious at ISO 1600.  Above that point we noticed colour changes and softening and shots taken at ISO 6400 were blotchy and unsharp.  Flash exposures fared a little better, although colour noise and colour shifts were evident in shots taken at ISO 1600 and shots taken at ISO 6400 were equally blotchy and unsharp.

Lateral chromatic aberration was generally low, as shown in the graph below, in which the red line marks the boundary between ‘negligible' and ‘low' CA and the green line separates ‘low' from ‘moderate'. However, we observed some coloured fringing in outdoor shots, particularly at longer focal length settings.

Close-up capabilities were generally good and the 1 cm Macro setting provided some impressive high-magnification shots with attractively blurred backgrounds. However, digital zoom shots tended to be slightly soft and artefact-affected, although good when the degree of magnification is considered.

Veiling flare reduced contrast and saturation in contre-jour shots, particularly at longer focal lengths.  Rectilinear distortion was evident at the wider focal lengths, changing to slight pincushion distortion at around the 9.3mm focal length point.  However, it never became severe from there onwards. We found no evidence of significant vignetting throughout the focal length range of the lens.

The test camera's auto white balance performed well under fluorescent lighting, producing images with neutral colours. However, shots taken in incandescent lighting retained a noticeable orange cast.  The camera pre-sets tended to over-correct for fluorescent lighting, although not under tungsten lights.
Manual measurement produced good colour neutrality under both types of lighting. Flash performance was generally good. The review camera was able to illuminate an average-sized room at ISO 500 and produced evenly-exposed flash shots from ISO 100 onward, although shots taken at ISO 3200 and ISO 6400 showed an increasing yellow cast.

The image stabilisation system was effective for movie capture as for stills and, for the latter, enabled us to use shutter speeds as slow as 1/6 second with a focal length of 19.6mm. Movie quality was good in VGA mode but average with the HD settings, which were often affected by colour casts and aberrations, particularly when shooting slightly backlit subjects. The relatively slow frame rate in the 702p mode also produced slightly jerky clips. The lack of a wind filter reduced the quality of the fairly ordinary monaural soundtrack when shooting outdoors.

The review camera powered-up in just under two seconds and we measured an average capture lag of 0.75 seconds, which confirmed our initial subjective judgment that the camera's autofocusing system was relatively slow. With pre-focusing, lag time was reduced to less than 0.1 second. It took 2.7 seconds on average to process a JPEG image at maximum resolution.

In the H continuous shooting mode, we were able to record 16 shots in 1.2 seconds, while the M mode captured seven shots in 0.7 seconds and the L setting recorded seven shots in 1.3 seconds. Processing times varied for each of the continuous shooting settings, with the H mode taking 18 seconds to process 16 shots, the M mode taking 10 seconds for seven shots and the L mode taking 11.3 seconds.

Buy this camera if:
- You're looking for an ultra-zoom digicam with good wide-angle coverage, plenty of adjustable controls, in-camera editing and effective image stabilisation.
- You want manual flash adjustment plus a good range of flash settings.
- You want to shoot widescreen video for playback on an HD TV set.
- You'd enjoy taking very close ‘macro' shots.

Don't buy this camera if:
- You want to shoot raw files (this camera is restricted to JPEG capture).
- You need a camera with fast response times.
- You require high performance levels in dim or contrasty lighting.
- You require high-quality Full HD video with stereo sound. 

IMATEST GRAPHS

SAMPLE IMAGES

Auto white balance with incandescent lighting.

Auto white balance with fluorescent lighting.

Close-up. 4.6mm focal length, ISO 50, 1/60 second at f/2.8.

Super macro. 9.3mm focal length, ISO 160, 1/100 second at f/3.5.


Showing the effectiveness of the image stabilisation system: 19.6mm focal length, ISO 50, 1/6 second at f/5.6.

Long exposure at ISO 50: 6mm focal length,4 seconds at f/3.2.

Night exposure at ISO 1600: 6mm focal length,1.6 seconds at f/8.

Night exposure at ISO 6400: 6mm focal length,1/2 seconds at f/8.

Flash exposure at ISO 100: 22.8mm focal length,1/125 seconds at f/4.

Flash exposure at ISO1600: 22.8mm focal length,1/125 seconds at f/4.

Flash exposure at ISO6400: 22.8mm focal length,1/125 seconds at f/4.

4.6mm focal length, ISO 50, 1/400 second at f/7.1.


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

 


Crops from opposite edges of the above image at 100% enlargement showing edge softening.

110.4mm focal length, ISO 50, 1/400 second at f/5.

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

Strong backlighting: 4.6mm focal length, ISO 50, 1/400 second at f/6.3.

Strong backlighting: 110.4mm focal length, ISO 100, 1/125 second at f/5.

Moderate backlighting: 110.4mm focal length, ISO 100, 1/500 second at f/5.

Digital zoom: 110.4mm focal length, ISO 50, 1/125 second at f/5.

Below: Still frames from video clips.

720p video with contre-jour lighting.

720p with normal lighting.

VGA video.

Image sensor: 6.13 x 4.6 mm CCD sensor with  (12.0 megapixels effective)
Lens:  4.6-110.4mm f/2.8-5.0 zoom lens (26-624mm in 35mm format)
Zoom ratio: 24x optical; approx. 6.25x digital
Image formats: Stills - JPEG (Exif 2.21); Movies -  AVI (Motion-JPEG) with PCM monaural sound (WAV)
Image Sizes: Stills - 4:3 aspect: 4000 x 3000, 3072 x 2304, 2592 x 1944,2048 x 1536, 1024 x 768, 640 x 480; 3:2 aspect: 4000 x 2672; 16:9 aspect: 4000 x 2256; 1:1 aspect: 2992 x 2992; Movies - 1280 x 720 (HD) at 15 fps, 848 x 480 at 30 fps; 640 x 480, 320 x 240 at 15 or 30 fps
Shutter speed range: 1/4 to 1/4000 second (to 4 sec. in Tv, Av , M and Night Scene modes)
Self-timer: 2 or 10 seconds delay
Image Stabilisation: CCD-shift Shake Reduction plus ISO boost
Exposure Compensation: +/- 2EV in 1/3EV steps
Focus system/range: TTL contrast-detection AF with 9-point AF, Spot AF, Auto tracking AF; range 40 cm to infinity; macro to 1 cm (middle zoom position)
Exposure metering/control: Multi-segment, Centre-weighted, Spot metering
Shooting modes: Auto Picture, Sport, Digital SR, Movie, USER, Manual, Av, Tv, Program, SCN (Landscape, Flower, Portrait, Backlight, Half-length Portrait,  Night Scene, Night Scene Portrait, Stage Lighting, Surf & Snow, Baby, Kids, Pet, Food, Fireworks, Frame Composite, Party, Museum, Sunset, Digital Wide, Digital Panorama),  Green
ISO range: Auto, ISO 50 to 6400 in 1EV steps
White balance: Auto, Daylight, Shade, Tungsten, Fluorescent (x3), Manual
Flash modes/range (ISO auto): On, Off, Red-eye reduction with pre-flash, Slow Synchro with or without red-eye reduction; range 0.2 to 9.1 m (ISO auto)
Sequence shooting: Max. 11 fps at 5M size, 21 shots
Storage Media: 33.6MB internal memory plus SD/SDHC expansion slot
Viewfinder: Electronic viewfinder approx. 200k dots
LCD monitor: 2.7-inch LCD monitor with 230,000 dots
Power supply:  Rechargeable D-LI92 lithium-ion battery; CIPA rated for approx. 170 shots/charge
Dimensions (wxhxd): 110.5 x 82.5 x 89.5 mm
Weight: 390 grams (without battery and card)