In summary
The GX8 will appeal to photographers looking for a solidly constructed weatherproof CSC with a generous grip and plenty of user-adjustable controls. The 4K shooting modes are likely to be appealing as well.
The ability to use unstabilised M4/3 lenses with the body-integrated IS system is another attractive feature, particularly if you already own Olympus or other third-party lenses.
The move up to 20-megapixel resolution is not without issues and you’ll need something better than the kit lenses to get the most from this camera. Fortunately, both Panasonic and Olympus have some suitable, high-performing lenses to choose from, both zooms and primes.
Full review
This review supplements the wide-ranging ‘First Look‘ we published in August for Panasonic’s latest rangefinder-style Lumix model, the DMC-GX8. Based on the two-year-old DMC-GX7, it is the first M4/3 camera with a 20-megapixel image sensor and uses the same Venus Engine image processor as the esteemed GH4. This permits improvements to performance and functionality as well as enabling 4K movie recording.
Angled view of the new Panasonic Lumix DMC-GX8 in black, fitted with the 14-42mm f/3.5-5.6 kit lens. (Source: Panasonic.)
The feature that distinguishes the GX-series cameras from other G-series models in Panasonic’s stable is built-in sensor-shift stabilisation , which allows users to take advantage of the usually cheaper, smaller and lighter lenses produced by third-party manufacturers, among them Olympus. Panasonic’s new Dual I.S. stabilisation technology also enables the sensor-shift to be combined with the company’s standard lens-based O.I.S. system to increase the range of movements that can be compensated for. According to Panasonic improvements of up to 3.5x at wide angle and 1.5x for telephoto stabilisation performance are possible when shooting stills.
The top panel of the Lumix DMC-GX8 in silver with no lens fitted. (Source: Panasonic.)
Rear view of the Lumix DMC-GX8 in black with the fully-articulating monitor extended. (Source: Panasonic.)
We’ve covered most aspects of the camera’s build and ergonomics as well as its sensor and image processing and movie capabilities quite comprehensively in our ‘First Look‘. It also contains details on the types of photographers who could find the GX8 appealing. We see no need to repeat this so in this review we’ll concentrate upon the camera’s actual performance.
While Panasonic provided the pre-production camera with two lenses, the 14-42mm f/3.5-5.6 and 14-140mm f/3.5-5.6 , only the 14-42mm f/3.5-5.6 lens was supplied with the production unit so all quantitative tests were carried out with this lens. However, we also used the camera with our own Olympus M.Zuiko Digital ED 40-150mm f/4.0-5.6 R to check compatibility with the IS system.
Panasonic is offering the GX8 in four formats in Australia: as body only for AU$1399, with the Lumix G Vario 14-42mm f/3.5-5.6 II ASPH./MEGA O.I.S. lens for AU$1499, as a Zoom kit with the 14-140mm f/3.5-5.6 lens for AU$1999, as a twin lens kit with the addition of a 45-150mm f/4-5.6 lens for AU$1699 and as a Pro kit with the 12-35mm f/2.8 lens for AU$2399.
Performance
Subjective assessments of image files from the review camera showed them to be detailed, sharp and with natural-looking colours. Panasonic’s revised colour processing, which separates hue, saturation, and luminosity adjustments, appears to have paid off as our Imatest tests showed a good correspondence between the actual and ideal colour values in JPEG files.
Metering was as accurate as we’ve come to expect from G-series cameras and the default Standard setting in the iDynamic mode delivered well-balanced highlight and shadow detail, although there was a tendency for highlights to blow out in very contrasty situations. The in-camera dynamic range adjustments went some way towards controlling blow-out but had difficulties with very contrasty subjects.
Autofocusing was universally fast and accurate, even in low light levels at night. Both the Starlight AF mode and the new AF tracking algorithms, which utilise colour data as well as subject size and motion have been effective in ensuring superior autofocusing performance across the board. (Panasonic claims an improvement of approximately 200% in AF speeds over the system in the GX7.)
The digital zoom function delivered satisfactory resolution for both stills and movie clips with 2x magnification but, for still shots, both sharpness and colour intensity suffered with 4x magnification. Better results were obtained with the Extra Tele Conversion function, which reduces file sizes, produces better-looking pictures when small images are preferred.
And while the stabilisation system delivered the expected amount of camera shake corrections when shooting stills and movie clips, it was hard pressed at the highest digital zoom magnification. In low light levels, a significant percentage of digital zoom shots were slightly blurred.
Although the sensor-shift stabilisation system isn’t engaged in movie mode, the GX8 includes an electronic Dual I.S. stabilisation function that complements the 2-axis system in stabilised lenses to provide a combined 5-axis Hybrid O.I.S. system. Unfortunately, it doesn’t work when 4K movie mode is selected, leaving the camera vulnerable to camera shake when slow shutter speeds are used.
In our Imatest tests, neither JPEG nor RW2.RAW files could meet expectations for a 20-megapixel camera with the supplied kit lens, although we suspect that a better lens would have delivered significantly higher resolution. It is well known that lens quality is the main limiter of definition with high-pixel count sensors.
The fact that raw files came close to meeting expectations in the centre of the frame suggests a better lens would probably produce sharper images than we obtained. Nevertheless, resolution held up very well with both file types across the camera’s sensitivity range, as shown in the graph of our Imatest results below.
Long exposures taken in dim lighting showed little visible noise up to ISO 3200, with noise becoming progressively more visible. By ISO 12800 granularity was noticeable in test shots and there were some visible colour shifts plus a reduction in the saturation of some hues. These factors became increasingly visible at ISO 25600. (We couldn’t test flash performance since the camera lacks a built-in flash and no accessory flash was supplied.)
White balance performance was typical of many cameras we test, with the auto setting failing to eliminate the warm cast from incandescent lighting. No in-camera correction is provided for fluorescent lighting but both the auto setting and manual measurement produced natural colour reproduction. Manual measurement also eliminated colour casts with incandescent lighting. The camera provides plenty of scope for fine-tuning colour rendition via the touch screen.
Video quality was outstanding at all resolution settings in both movie formats. It appeared to be on a par with the clips we recorded with the GH4, even though the GX8 doesn’t quite match that camera’s movie capabilities. The contrast-detection AF system worked as well in movie mode as for stills capture and re-focusing during pans and zooms was pleasingly fast.
Users have plenty of aids to control picture quality while shooting movie clips, including focus peaking for manual focusing and luminance control that lets users select output footage levels. There are also some interesting cinema-style colour modes and a variety of effects that can be applied to movie clips. But without microphone and headphone jacks, controlling soundtracks is more difficult than when shooting with the GH4.
The camera was well able to handle contrasty lighting in movie mode and clips were sharp and clear with smooth recordings of moving subjects and during pans. Most of Panasonic’s existing lenses are compatible with Dual I.S. stabilisation and the rest are scheduled to be made compatible through firmware updates that should be released by February next year. The Lumix G Vario 14-42mm f/3.5-5.6 II ASPH Mega O.I.S. (H-FS1442A) supplied with the camera supported Dual I.S. stabilisation.
Our timing tests were conducted with a 16GB Panasonic SDHC Class 10 UHS-3card, which was supplied with the camera. The review camera powered up within a second and we measured an average capture lag of less than 0.1 seconds regardless of whether the viewfinder or monitor was used for shot composition. This lag was eliminated when shots were pre-focused.
Shot-to-shot times averaged 0.45 seconds without flash and 3.6 seconds with. There’s no indicator LED on the camera to show when files have been processed so we were unable to measure processing times. However, the view on the monitor and EVF screen refreshed after 4.1 seconds when a shot was recorded, regardless of the quality setting.
We only timed two of the four continuous shooting modes the review camera offers: Super high-speed and High-speed. The former can record at 40 frames in one second but is JPEG-only, while the latter records JPEG and raw frames at 10 frames/second. Live view is not available during either burst. The Super high-speed mode can record up to 60 frames.
In the High-speed mode, the review camera recorded 40 Large/Fine JPEG frames in 7.8 seconds without showing any sign of slowing (the camera’s manual suggests the buffer can accommodate 100 or more JPEG frames). With RW2.RAW files the camera recorded 37 frames in 7.6 seconds in the high-speed mode. A processing indicator icon was displayed on the monitor, enabling us to see it took 20.4 seconds to process this burst. With RAW+JPEG pairs, 34 frames were recorded in 6.7 seconds but it took just over 30 seconds to process this burst.
The middle and low speed settings record at seven and two frames/second respectively. Live view is supported during capture and both settings are available for bursts of RW2.RAW files. Frames are processed on-the-fly and processing is completed within a second of the last frame captured.
Conclusion
Although not as small or elegant as the Olympus OM-D cameras,the GX8 will appeal to photographers looking for a solidly constructed weatherproof CSC with a generous grip and plenty of user-adjustable controls. The 4K shooting modes are likely to be appealing as well.
The ability to use unstabilised M4/3 lenses with the body-integrated IS system is another attractive feature that could sway some potential buyers, particularly if they already own Olympus (or other third-party) lenses. The GX8 could also be attractive to owners of Olympus M4/3 kits who want 4K movie recording.
The move up to 20-megapixel resolution is not without issues and you’ll need something better than the kit lenses to get the most from this camera. Fortunately, both Panasonic and Olympus have some suitable, high-performing lenses to choose from, both zooms and primes.
Finally, at AU$1399, the GX8 is quite pricey for an M4/3 CSC so we have a few reservations about nominating it as an Editor’s Choice (although it would qualify with a better lens). The MSRP (manufacturer’s suggested retail price) for the GX8 body in North America is just under US$1200, which is more than the local price when currency conversion is taken into account. Adding shipping and insurance costs would make the overall price even higher so it’s much better to purchase this camera locally.
Panasonic USA had not released details of the pricing and availability of the kit lens options for North America when this review was written. But we’re sure they won’t end up cheaper for Australian buyers than the prices in the local stores.
SPECS
Image sensor: 17.3 x 13.0 mm Live MOS sensor with 21.77 million photosites (20.3 megapixels effective)
Image processor: Venus Engine
Lens mount: Micro Four Thirds
Focal length crop factor: 2x
Digital zoom: 2x, 4x (Live View only)
Image formats: Stills: JPEG (DCF, Exif 2.3), RAW, MPO (with 3D lens); Movies: AVCHD (Audio format: Dolby Digital 2ch), MP4 (Audio format: AAC 2ch)
Image Sizes: Stills: 4:3 ““ 5184 x 3888, 3712 x 2784, 2624 x 1968; 3:2 ““ 5184 x 3456, 3712 x 2480, 2624 x 1752; 16:9 ““ 5184 x 2920, 3840 x 2160, 1920 x 1080; 1:1 ““ 3888 x 3888, 2784 x 2784, 1968 x 1968; Movies: 4K – 3840 x 2160 24/25p 100Mbps, [Full HD] 1920 x 1080: 50p/28Mbps, 50i/17Mbps 25p/20Mbps; [HD] 1280 x 720 25p/10Mbps, [VGA] 640 x 480 25p/4Mbps
Image Stabilisation: Image Sensor Shift Type
Dust removal: Supersonic wave filter
Shutter speed range: Focal-plane shutter (mechanical): 60-1/8000 second plus Bulb (Max. 30 minutes); Electronic shutter: 1/16,000 – 1 second (min. 1/25 second for movies)
Exposure Compensation: +/- 5 EV in 1/3EV steps (+/-3EV for movies)
Exposure bracketing: 3, 5, 7 frames in 1/3, 2/3 or 1 EV steps, Max. ±3 EV, single/burst
Other bracketing options: WB – 3 exposures in blue/amber axis or in magenta/green axis
Self-timer: 2 or 10 seconds delay plus 10 sec., 3 images
Focus system: Contrast AF system with DFD technology plus Face/Eye Detection, Tracking, 49-Area/Custom Multi/1-Area / Pinpoint AF
Focus modes: AFS (Single) / AFF (Flexible) / AFC (Continuous) / MF
Exposure metering: 1728-zone multi-pattern sensing system with Multiple, Centre-weighted and Spot metering patterns
Shooting modes: Program AE, Aperture Priority AE, Shutter Priority AE, Manual
Creative Control: Expressive, Retro, Old Days, High Key, Low Key, Sepia, Monochrome, Dynamic Monochrome, Rough Monochrome, Silky Monochrome, Impressive Art, High Dynamic, Cross Process, Toy Effect, Toy Pop, Bleach Bypass, Miniature Effect, Soft Focus, Fantasy, Star Filter, One Point Colour, Sunshine
Photo Style Modes: Standard, Vivid, Natural, Monochrome, Scenery, Portrait, Custom, plus Cinelike D, Cinelike V when Creative Video Mode is selected.
Programmable Function buttons: 13
Colour space options: sRGB and Adobe RGB
ISO range: Auto, Intelligent ISO, ISO 100 to ISO 25600 adjustable in 1/3 EV steps
White balance: Auto, Daylight, Cloudy, Shade, Incandescent, Flash, White Set 1, 2 , Colour temperature setting; Blue/Amber, Magenta/Green bias adjustments
Flash: TTL External Flash (Optional)
Flash modes: Auto*, Auto/Red-eye Reduction*, Forced On, Forced On/Red-eye Reduction, Slow Sync., Slow Sync./Red-eye Reduction, Forced Off (* For iA, iA+ only); 1st. Curtain Sync, 2nd Curtain Sync.
Flash exposure adjustment: +/-3EV in 1.3EV steps
Sequence shooting: Max. 10 frames/sec. with electronic shutter; 8 frames/sec. with mechanical shutter; 4K Burst: 30 frames/sec
Buffer capacity: Max. 100 Large/Fine JPEGs, 30 RAW files or RAW+JPEG pairs
Storage Media: SD, SDHC, SDXC cards (Compatible with UHS-I & UHS-3 standard SDHC / SDXC Memory Cards)
Viewfinder: Tilting OLED Live View Finder with 2,360,000 dots; approx. 100% field of view, approx. 1.54x magnification, 21mm eyepoint, -4.0 to +3.0 dpt dioptre adjustment, eye sensor (adjustable)
Monitor: Free-angle 3.0-inch OLED monitor with static touch control; 3:2 aspect ratio, 1.04 million dots, adjustments for Brightness, Contrast, Saturation, Red Tint, Blue Tint
Playback functions: 30-thumbnail display, 12-thumbnail display, Calendar display, Zoomed playback (Max. 16x), Slideshow (All / Picture Only / Video Only / 4K PHOTO / 3D / Category Selection / Favourite, duration & effect is selectable), Playback Mode (Normal / Picture / Video / 4K PHOTO / 3D Play / Category / Favourite), Location Logging, RAW Processing, Clear Retouch, Title Edit, Text Stamp, Video Divide, Time Lapse Video, Stop Motion Video, Resize, Cropping, Rotate, Rotation Display, Favourite, DPOF Print Set, Protect, Face Recognition Edit, Picture Sort, Creating Still Pictures from a Motion Picture
Interface terminals: USB 2.0 High Speed Multi; microHDMI TypeD / VIERA Link; AV-Out: Monaural Type, NTSC/PAL; 2.5mm jack for remote; 2.5mm jack for external microphone
Wi-Fi & NFC: Wi-Fi ““ IEEE 802.11b/g/n, 2412 MHz – 2462 MHz (1-11 ch), Wi-Fi / WPA / WPA2, Infrastructure mode; NFC ““ ISO/IEC 18092, NFC-F (Passive Mode); QR Code Connection
Power supply: Li-ion Battery Pack (7.2V, 1200mAh, 8.7Wh); CIPA rated for approx. 340 images (rear monitor), 320 images (LVF) with H-FS1442A lens
Dimensions (wxhxd): Approx. 133.2 x 77.9 x 63.1 mm (excluding protrusions)
Weight: Approx. 435 grams (body only); 487 grams with battery and card
TESTS
Based upon JPEG image files
Based upon RW2.RAW image files converted into 16-bit TIFF format with Adobe Camera Raw.
SAMPLES
Auto white balance with incandescent lighting.
Auto white balance with fluorescent lighting.
14mm focal length, ISO 100, 1/32 second at f/6.3.
42mm focal length, ISO 100, 1/250 second at f/6.3.
2x digital zoom; 42mm focal length, ISO 100, 1/250 second at f/6.3.
4x digital zoom; 42mm focal length, ISO 100, 1/400 second at f/8.
Close-up at 28mm focal length, ISO 200, 1/60 second at f/5.3.
An example of blown-out highlights in very contrasty lighting; 21mm focal length, ISO 200, 1/200 second at f/6.3 with -0.3EV compensation.
30 second exposure at ISO 100; f/3.5; 28mm focal length.
15 second exposure at ISO 800; f/4.6; 28mm focal length.
5 second exposure at ISO 3200; f/5; 28mm focal length.
2.5 second exposure at ISO 6400; f/5; 28mm focal length.
2 second exposure at ISO 12800; f/7.1; 28mm focal length.
1 second exposure at ISO 25600; f/9; 28mm focal length.
14mm focal length, ISO 100, 1/200 second at f/5.6.
Taken with Olympus 40-150mm lens at 123mm focal length, ISO 200, 1/320 second at f/5.6.
30mm focal length, ISO 3200, 1/50 second at f/5.4.
42mm focal length, ISO 400, 1/200 second at f/5.6.
42mm focal length, ISO 320, 1/100 second at f/5.6.
27mm focal length, ISO 200, 1/320 second at f/9.
21mm focal length, ISO 800, 1/125 second at f/8.
Still frame from a 3840 x 2160 4K video clip recorded at 25p, 100Mbps.
Still frame from a 3840 x 2160 4K video clip recorded at 24p, 100Mbps.
Still frame from 1920 x 1080 50p MP4 video clip recorded at 28Mbps.
Still frame from 1920 x 1080 25p MP4 video clip recorded at 20Mbps.
Still frame from 1280 x 720 25p MP4 video clip recorded at 10Mbps.
Still frame from 640 x 480 25p MP4 video clip recorded at 4Mbps.
Still frame from a 1920 x 1080 50p AVCHD video clip recorded at 28Mbps.
Still frame from a 1920 x1080i 50i AVCHD video clip recorded at 24Mbps.
Still frame from a 1920 x1080i 50i AVCHD video clip recorded at 17Mbps.
Still frame from 1920 x 1080 24p AVCHD video clip recorded at 24 Mbps.
Rating
RRP: AU$1399; US$1200
- Build: 8.8
- Ease of use: 8.5
- Autofocusing: 9.0
- Still image quality JPEG: 8.5
- Still image quality RAW: 8.5
- Video quality: 9.0
