Canon PowerShot SX50 HS - Photo Review - Chuyên Trang Chia Sẻ Kiến Thức Thời Trang Mới Nhất

Photo Review

Mục lục

In summary

Buy this camera if:
– You want a super-zoom that can record raw files and provides most of the controls and functions offered in serious DSLR cameras.
– You’d like the ability to shoot Full HD (1080p) video clips with stereo soundtracks.
– You want sophisticated image stabilisation.

Don’t buy this camera if:
– You require high resolution and low noise levels at high ISO settings.
– You require high burst speeds for raw files.
– You need fast cycle times for processing shots.
– You want to take long exposures at night.
– You’re a sports or wildlife photographer.

Full review

Canon’s PowerShot SX50 HS replaces the PowerShot SX40 HS at the top of the company’s ultra-zoom digicam range. Offering 50x optical zooming, it retains the 12.1-megapixel back-illuminated sensor and DIGIC 5 image processor of its predecessor. It’s Canon’s first ultra-zoom with raw file capture and it introduces sophisticated image stabilisation to support the zoom range, with compensation of up to 4.5 f-stops.

Front view of the PowerShot SX50 HS with the pop-up flash raised. (Source: Canon.)

Although the new camera is slightly smaller and six grams lighter than its predecessor, its price is $50 higher than the SX40 HS‘s was on its release. With its SLR-like styling and large hand-grip, the SX50 HS is roughly the same size as an entry-level DSLR camera plus kit lens.

Build and Ergonomics
Aside from the new lens, in most respects the basic body design is unchanged from the SX40 HS. Buttons and controls are well placed and spaced widely enough apart to suit most users’ hands (except very tiny ones with short fingers). The zoom is powered and driven by a conventional lever surrounding the shutter button, making it straightforward to operate.

The 4.3-215mm f/3.4-6.5 zoom lens covers a 35mm equivalent focal length range of 24mm to 1200mm. It features 13 elements, with three UD lenses included in a 10-group optical arrangement.

The lens retracts into its barrel when power is switched off. When the on button is pressed, the inner barrel extends 30 mm and then to 58 mm as you zoom in to the 215mm position (the equivalent of 1200mm in 35mm format). Eight focal length settings in 35mm equivalents are stamped on the extending section of the barrel.

Top view of the PowerShot SX50 HS with the inner lens barrel fully extended.

As in previous SX-series models, autofocusing and zooming are driven by ultrasonic motor (USM) and voice coil (VCM) motor technologies, which provide smooth transitions between focal lengths and fast and quiet autofocusing. Gyro sensors in the lens detect camera movements and transmit them to a controller that can discriminate between hand-shake and intentional camera movements and make appropriate corrections by moving elements in the lens to re-direct the light rays.

Close-up view of the camera, showing the new Seek (upper) and Lock (lower) buttons located on the side of the lens barrel.

To help users record subjects at high zoom ratios, Canon has equipped the SX50 HS with an Enhanced Zoom Framing Assist function that includes new Seek and Lock buttons (shown above). The Seek button can be pressed to make the lens zoom out to relocate subjects. Once the subject is located, releasing the button zooms the lens back to its telephoto focal length. The Lock button engages additional optical stabilisation to hold the subject in the frame until the shot is taken.

The rear panel and still sports a fully-adjustable 2.8-inch LCD monitor, although its resolution has been increased to 461,000 dots. The EVF retains a relatively resolution of approximately 202,000 dots, which is also comparatively low but much as you’d expect for the camera’s price.

Rear views of thePowerShot SX50 HS with the monitor extended (top) and reversed onto the camera. (below). (Source: Canon.)

The new camera uses the same type of battery as its predecessor and, as in the SX40 IS, the battery and memory card share a compartment in the base of the camera. The metal-lined tripod socket is close to the battery/card compartment and not in line with the lens axis. USB/AV-out and HDMI connectors are located under a rubber cover on the right hand side of the camera body.

Like its predecessor, the SX50 HS can accept a range of accessories, including Canon Speedlites 270EX II, 320EX, 430EX II, 580EX II and 600EX-RT plus the ST-E2 Speedlite Transmitter and SB-E2 Speedlite Bracket. A remote controller (RS-60E3) is available, along with an off-camera shoe cord (OC-E3) and filter adaptor (FA-DC67A).

Sensor and Image Processing
The physical size of the SX50 HS’s sensor hasn’t changed since the previous model; nor has the resolution. But Canon has enabled the new camera to record raw files, although only at the highest resolution and with a 4:3 aspect ratio. RAW+JPEG capture is also supported.

In line with the SX series, four sizes are provided for each of four aspect ratio settings with two compression levels available via the Display button. Typical image sizes for the 4:3 aspect ratio are shown in the table below

Aspect Ratio

Image size

Pixels

Compression

Fine

Normal

4:3

RAW

4000 x 3000

17.9MB

L (Large)

5.8MB

3.65MB

M1 (Medium 1)

2816 x 2112

3.29MB

2.15MB

M2 (Medium 2)

1600 x 1200

1.07MB

0.62MB

S (Small)

640 x 480

0.29MB

0.2MB

Sensitivity settings in the new camera have been extended to ISO 6400, up from ISO 3200 in the previous model. Manual adjustments are available in 1/3EV steps from ISO 80 and the setting selected in the Auto mode is displayed in the viewfinder when the shutter button is half-pressed.

The SX50 HS supports the same movie resolutions as its predecessor, offering Full HD video recording at 1920 x 1080 pixels with a frame rate of 24 frames/second (fps), HD and VGA at 30 fps and two slow motion movie modes. One of them records at 120 fps with VGA resolution and the other at 240 fps with QVGA (320 x 240 pixels).

For the slow-motion settings, the maximum clip length is 30 seconds. Clips recorded at 120 fps play back over approximately two minutes, while 240 fps clips play back over roughly four minutes.

The maximum clip size for the HD and 30 fps VGA video clip is 4GB but recording will also stop automatically after 29 minutes and 59 seconds. The table below shows typical recording times at different resolutions.

Movie quality

Resolution

Frame rate

Capacity with 8GB memory card

1920

1920 x 1080 pixels

24 fps

29 minutes 39 seconds

1280

1280 x 720 pixels

30 fps

42 minutes 11 seconds

640

640 x 480 pixels

88 minutes 59 seconds

iFrame

1280 x 720 pixels

27 minutes 39 seconds

120

640 x 480 pixels

120 fps

30 seconds

240

320 x 240 pixels

240 fps

30 seconds

You can engage movie mode without selecting it on the mode dial by pressing the Movie button on the rear panel and stop recording with a second press of the same button. If the camera is set for one of the HD modes, the monitor and EVF screens are cropped to the 16:9 aspect ratio to aid composition.

Optical zoom is supported while recording video clips and Canon’s Dynamic IS mode reduces the rolling motion that can affect movies when they are recorded while the photographer is walking or moving. Powered IS provides motion compensation at longer focal length settings.

As with previous models, autofocusing will re-adjust when required; face detection also engages automatically and the camera will adjust exposure levels and white balance when necessary. Soundtracks are recorded in stereo and in Movie mode, the menu includes a page with adjustments for the microphone level as well as a wind cut filter that be turned on or off.

Controls
Most controls remain unchanged from the previous model, with the same restrictions in the P, A, S and M shooting modes to minimise the incidence of image noise in shots. Noise reduction processing is automatically applied to long exposures and you can’t use sensitivities above ISO 80 with exposures longer than one second. High ISO noise reduction is applied by default but you can choose from three levels: Standard, High and Low.

Shooting modes are largely unchanged since the SX40 HS, although the Portrait and Landscape modes are now included in the Scene pre-sets and the Portrait setting gains a Soft Skin option. The Creative Filters setting on the mode dial includes the HDR (High Dynamic Range) multi-frame mode, while the other multi-frame setting, Handheld Night Scene is located in the Scene sub-menu.

Other Creative Effects include Fish-eye and Toy Camera (relocated from the Scene menu), as well as Miniature and various colour effects (Sepia. B&W, Super Vivid and Poster Effect). There’s also a Soft Focus effect, the strength of which is adjustable when you press the Display button and use the horizontal arrow pad buttons or the dial control.

Pressing the Display button also lets you toggle between the viewfinder and LCD monitor, offering two options for each. You can choose between image only and image plus shooting data and brightness histogram.

Like its predecessors, the SX50 HS provides two continuous shooting modes. The ‘normal’ mode is one of the drive settings accessed via the Func./Set button. (Other options are single-frame and continuous AF.)

In this mode, the frame rate is approximately 2.2 frames/second, with focus and exposure set when the shutter button is half-pressed. In the continuous AF mode, the AF frame is set to the centre of the field of view and the frame rate drops to 0.8 fps. More than 300 JPEGs can be recorded in these modes, if sufficient storage capacity is available.

The second continuous shooting mode is High-speed Burst HQ, which is located among the Scene presets. This mode is only available for JPEGs and enables up to 13 frames to be captured in one second at full resolution. Focus, exposure and colour balance are determined by the first shot.

Other settings carried over from the previous models include the ‘Smart Shutter’ mode (which includes face and smile detection), Wink and Face self-timer settings and the ‘Smart Auto’ mode (which uses scene detection technology).

A new Face ID function allows users to assign name and birthday information to up to 12 faces. This enables the camera to identify different faces as baby (aged below 2), children (aged between 2 to 12) or adult (aged above 13) for better integration with the Scene Detection technology. The Face ID function also makes it easy to find shots of logged people in playback mode.

Playback and Software
These are largely unchanged from the previous model and include in-camera corrections for brightness (i-Contrast) and red eyes in flash shots as well as an over-exposure warning that indicated blown-out highlights. Both brightness and RGB histograms are available in playback mode. Users can crop, resize and adjust image colours with the My Colours function in playback mode.

Interestingly, there’s no in-camera function for converting CR2.RAW files into editable JPEGs. That must be done with the supplied Digital Photo Professional software.

Movies can be trimmed at either end in the camera and an option is available to over-write the original clip. Clips recorded in Movie Digest mode can also be edited, although only by erasing the entire clip.

Performance
All super-zoom digicams involve compromises and the more manufacturers ‘stretch’ the capabilities of the technology, the more likely the effects of compromises will become obvious. We found such to be the case with the SX50 HS we received to review.

Extending the zoom range to 50x takes a severe toll on lens speed, which reduces shooting options when the minimum aperture the camera supports is f/8. Although a maximum aperture of f/3.4 is available at the shortest focal length, it’s quickly whittled away as you zoom in. By roughly a quarter of the way into the zoom range, it has closed down to f/5.6 and at full optical zoom, f/6.5 leaves you only three f-stops to work with.

You’ll be forced to increase the ISO sensitivity to maintain a fast enough shutter-speed to hand-hold the camera or resort to a tripod. In anything less than bright sunlight, obtaining acceptable sharpness is problematic, partly because images become progressively softer as sensitivity is increased but also because even the sophisticated image stabilisation struggles to counteract camera shake. (Examples are provided below.)

Canon has tried valiantly to overcome the latter problem with its Intelligent IS function but it’s a big ask to expect any system to provide the claimed 4.5 f-stop compensation at the high magnification ratios this lens produces. The Enhanced Zoom Framing Assist Seek and Lock buttons provide some assistance when attempting to focus on distant subjects at long focal lengths but they’re very difficult to use when framing moving subjects, such as birds in flight ““ or even helicopters, which move more slowly. We can’t really recommend this camera to birders for that reason.

The AF system also laboured to capture and hold focus in dim lighting. Sometimes it was successful; at others not; particularly at the longest focal lengths and in low-contrast conditions. Roughly 40% of shots we took at the 215mm focal length were slightly (or grossly) unsharp.

We found all the images we shot to be slightly soft straight out of the camera ““ and slightly softer than similar shots taken when we reviewed the SX40 HS roughly a year ago. Imatest testing confirmed these findings, showing the review camera failed to meet expectations for a 12-megapixel camera at any lens aperture/focal length combination we were able to measure. This was true with both JPEG and CR2.RAW files.

Imatest also showed resolution declined progressively as ISO sensitivity was increased, remaining relatively high between ISO 80 and ISO 400 then tailing off quite sharply thereafter. The graph below shows the results of our tests.

Lack of space in our testing set-up prevented us from evaluating the entire zoom range but we were able to make measurements for roughly a quarter of it. Across this range, edge softening was evident at all apertures and focal lengths we tested. The best performance was measured at a focal lengths of 8.5mm with the widest lens aperture, as shown in the graph below.

Lateral chromatic aberration ranged between the ‘negligible’ and ‘low’ bands and we found no evidence of coloured fringing in test shots of high-contrast subjects. In the graph below, the red line marks the border between ‘negligible’ and ‘low’ CA, the green line separates ‘low’ and ‘moderate’ CA.

Close-up performance was competent, although at the extreme ends of the Macro range, shots were slightly softer than expected. At 4.3mm, the camera will focus on subjects that almost touch the front element of the lens.

With full zoom extension, the minimum focusing distance is listed as 1.3 metres in the specifications sheet, although we found it closer to 1.5 metres in practice. Bokeh was surprisingly pleasant in close-up shots taken with longer focal lengths, despite the small aperture settings required.

Digital zoom shots captured in bright conditions were as sharp as normal tele shots. In low light levels, shots were much softer due to the inevitable problems with using at long focal lengths that we’ve outlined above. The review camera performed well when presented with strong backlighting, provided the light source was out of the frame.

The auto white balance setting failed to eliminate the orange cast of incandescent lighting but produced close-to-neutral colours under fluorescent lights. Both pre-sets delivered a neutral colour balance. Manual measurement produced similar results.

Video quality was similar to the clips we shot with the SX40 HS, although the soundtracks were slightly clearer, thanks to stereo recording and the ability to control recording levels in the camera. The wind cut filter suppressed but didn’t totally remove wind noise.

The AF system had trouble keeping up with fast pans and fast-moving subjects. Focus tracking performed well at shorter focal lengths but the system encountered problems towards the longer end of the zoom range, causing recordings to be slightly jumpy.

Overall response times were similar to the SX40 HS. The camera took just over a second to power up and slightly longer to shut down again. Zooming in from the 4.3mm position to 215mm took roughly four seconds in the stills mode and around ten seconds when the movie mode was engaged.

Shot-to-shot times averaged 2.1 seconds without flash and 6.9 seconds when flash was used. We measured an average capture lag of 0.35 seconds, which reduced to 0.15 seconds when shots were pre-focused. Despite having an indicator LED on the rear panel, the camera provided no reliable way to evaluate when images were processed as its blinking rate was too slow for precise measurements.

In the continuous shooting mode, the review camera recorded 10 JPEG frames in 4.2 seconds. Switching to RAW+JPEG capture extended the time to record 10 shots to 9.5 seconds, indicating files are processed on-the-fly.

The High-Speed Burst HQ mode, the camera recorded eight high-resolution JPEGs (the buffer limit) in 0.8 seconds, which is somewhat slower than the specified 13 fps rate. Raw files can’t be recorded in this mode.

SPECS

Image sensor: 6.17 x 4.55 mm High Sensitivity BSI-CMOS sensor with 12.8 million photosites (12.1 megapixels effective)
Image processor: DIGIC 5
Lens: 4.3-215mm f/3.4-6.5 zoom lens (24-1200mm in 35 mm format)
Zoom ratio: 50x optical, up to 2x digital
Image formats: Stills – JPEG (DCF / Exif 2.3), RAW (12-bit, CR2; Movies – MOV (Image data: H.264; Audio data: Linear PCM Stereo)
Image Sizes: Stills – 4:3 Aspect: 4000 x 3000, 2816 x 2112, 1600 x 1200, 620 x 480; 3:2 Aspect: 4000 x 2664, 2816 x 1880, 1600 x 1064, 640 x 424; 16:9 Aspect:4000 x 2448, 2816 x 1584, 1920 x 1080,640 x 360; 1:1 Aspect: 2992 x 2992, 2112 x 2112, 1200 x 1200,480 x 480; 4:5 Aspect: 2400 x 3000, 1696 x 2112, 960 x 1200,384 x 480; Movies – 1920 x 1080 at 24 fps, 1280 x 720, 640 x 480 at 30 fps; iFrame: 1280 x 720 30fps
Shutter speed range: 15-1/2000 seconds (in Tv and M modes)
Self-timer: 2 or 10 seconds delay plus Custom, Smile Shutter, Wink Self-Timer, Face Self-Timer
Image Stabilisation: Optical (Lens Shift Type), approx. 4.5 steps
Exposure Compensation: +/- 3EV in 1/3EV steps
Focus system/range: Contrast-based AF with Continuous, Servo AF, Manual Focus modes; Face AiAF, Tracking AF, Centre, FlexiZone areas; range: 5 cm to infinity; macro 0 cm to 50 cm
Exposure metering/control: Evaluative, Centre-weighted average, Spot metering
Shooting modes: Intelligent Auto (with Scene Detection), P (Program), Tv (Shutter Priority), Av (Aperture Priority), M (Manual), C1 (Custom 1), C2 (Custom 2), SCN (Portrait, Smooth Skin, Smart Shutter, High-speed Burst HQ, Handheld Night Scene, Snow, Fireworks, Stitch Assist), Creative Filters (High Dynamic Range, Fisheye Effect, Miniature Effect, Toy Camera Effect, Soft Focus, Monochrome, Super Vivid, Poster Effect, Colour Accent, Colour Swap); Movie (Standard, iFrame, Super Slow Motion), Movie Digest
ISO range: Auto, ISO 80-6400 in 1/3 EV steps
White balance: Auto, Daylight, Cloudy, Tungsten, Fluorescent, Fluorescent H, Flash, Underwater, Custom 1, Custom 2
Flash modes/range (ISO auto): Auto, on, off, Slow Synchro, Red Eye Correction, Red Eye Reduction, Second Curtain Synchro, FE Lock, Safety FE, Manual Flash Output; range: 50 cm to 5.5 m
Sequence shooting: Approx 2.2 shots/sec (P mode) / Approx 13 shots/sec (High-speed Burst HQ mode)
Storage Media: SD, SDHC, SDXC memory cards
Viewfinder: EVF with approx. 202,000 dots
LCD monitor: 2.8-inch vari-angle TFT LCD with approx. 461,000 dots; 4:3 aspect ratio
Power supply: NB-10L rechargeable lithium-ion battery; CIPA rated for approx. 335 shots/charge with EVF; 315 shots/charge with LCD monitor
Dimensions (wxhxd): 122.5 x 87.3 x 105.5 mm
Weight: Approx. 551grams (without battery and memory card)

TESTS

For JPEG files.

For CR2.RAW files processed with Digital Photo Professional.

SAMPLES

Auto white balance with incandescent lighting.

Auto white balance with fluorescent lighting.

4.3mm focal length, ISO 100, 1/1000 second at f/5.

215mm focal length, ISO 100, 1/200 second at f/6.5.

Digital zoom; 215mm focal length, ISO 100, 1/200 second at f/6.5.

Macro mode; 4.3mm focal length, ISO 100, 1/50 second at f/3.4.

Macro mode; 184mm focal length, ISO 400, 1/160 second at f/6.5.

15-second exposure at ISO 80; 5mm focal length, f/3.5.

1-second exposure at ISO 3200; 5mm focal length, f/3.5.

1-second exposure at ISO 6400; 5mm focal length, f/4.5.

Flash exposure at ISO 80; 26mm focal length, 1/60 second at f/5.

Flash exposure at ISO 400; 26mm focal length, 1/60 second at f/5.

Flash exposure at ISO 3200; 26mm focal length, 1/60 second at f/5.

Flash exposure at ISO 6400; 26mm focal length, 1/60 second at f/5.

Blown-out highlights in a shot of a subject with a wide brightness range; 4.3mm focal length, ISO 100, 1/800 second at f/5.6.

Digital zoom shot from the same vantage point with ISO 400 sensitivity; 215mm focal length, 1/400 second at f/6.5.

Strongly backlit subject; 4.3mm focal length, ISO 80, 1/1000 second at f/6.3.

The same subject photographed with a longer focal length; 17mm focal length, ISO 100, 1/1000 second at f/7.1.

Bokeh with maximum optical zoom; 215mm focal length, ISO 100, 1/25 second at f/6.5.

4.3mm focal length, ISO 100, 1/30 second at f/3.4.

Image softening with long focal length and high ISO; 215mm focal length, ISO 800, 1/250 second at f/6.5.

Tracking autofocus with moving subject (the only acceptably sharp image in a sequence of five shots); 44mm focal length, ISO 400, 1/800 second at f/5.6.