Camera Accessories

Initially the Lumix G Vario HD 14-140mm, f/4.0-5.8 ASPH./MEGA O.I.S. lens will be the main kit lens supplied with the GH1 body. However, it is also being sold as a stand-alone product, which is why we've reviewed it separately. Consisting of 17 elements in 13 groups, it includes four non-spherical elements and two ED (Extra-low dispersion) elements. This lens has been designed for both still and video capture, which makes it something of a novelty.

With a diameter of 70 mm and measuring 84 mm from the tip of the lens to the base of the lens mount at the 14mm position, its overall size is relatively small for its zoom range. Zooming out to 140mm extends the front of the lens by approximately 60mm. Overall weight is approximately 460 grams. The front of the lens is threaded to accept 62 mm filters.

The Lumix G Vario HD 14-140mm, f/4.0-5.8 ASPH./MEGA O.I.S. lens shown without the supplied petal-shaped lens hood. (Source: Panasonic) 

Built from high-quality polycarbonate plastic, this lens has a metal bayonet mounting plate with a gunmetal grey ring between the camera body and the zoom and focus rings. This ring carries the on/off slider switch for the built-in MEGA O.I.S. stabilisation system, which engages quickly and works almost noiselessly. Inside the mounting plate are 11 electrical contacts that enable the camera to interact with the lens.

The iris diaphragm has seven blades and closes to create a circular aperture. Minimum aperture at all focal lengths is f/22. The focus ring is about 6 mm wide and made from hard, ribbed plastic. It rotates through 360 degrees and there are no stops for setting close-up or infinity positions. The front element of the lens doesn't rotate during focusing, enabling use of angle-critical filters and other attachments.

Supplied with the lens is a 'petal-shaped' hood that attaches via a bayonet mount. When fitted it adds approximately 41 mm to the overall length. A clip on lens cap and end cap are also provided.

Handling
The G Vario HD 14-140mm f/4.0-5.8 lens feels comfortable on the Panasonic DMC GH1 body where its size and weight are well balanced enough for you to operate the camera and lens with one hand, if you wish. However, accessing the key controls is only possible with two-handed operation.

The metal bayonet mount is easy to attach to the camera body and fits snugly as does the cylindrical lens hood, which also attaches via a bayonet mounting. The zoom ring is covered by a ribbed, rubberised ring roughly 25mm wide. It turns smoothly with minimal creeping and rotates through roughly a quarter of a turn. No zoom lock is provided. As you move the zoom ring, the maximum aperture changes with focal length as follows:

The focusing ring is 14 mm wide with a 10 mm wide rubber grip. The ridges on this grip ring are narrower than those on the zoom ring. The focusing ring moves through 360 degrees and requires a lot of turning to go from the closest focus to infinity. The GH1 provides some useful manual focusing assistance via the MF Assist function, which enlarges the centre of the image on both the LCD monitor and the EVF. We found no tendency for the lens to 'creep' when it was carried pointing downwards.

Performance
Test pictures showed the review lens to have no evident rectilinear distortion and exposures appeared even across the entire frame. Lateral chromatic aberration was consistently negligible throughout our tests and we found no evidence of coloured fringing when test shots were enlarged to 100%. The graph below shows the results of our tests on shots taken with the focal lengths we were able to cover at ISO 100 and an aperture of f/8. (The red line marks the border between 'negligible' and 'low' CA.)

Imatest revealed a considerable degree of corner and edge softening at wide apertures, throughout the focal length range. At focal lengths of 70mm and longer, these differences between centre and edge resolutions were barely visible in test shots.  Diffraction began to degrade resolution at around f/16 and we wouldn't recommend using this lens at smaller apertures.  The graph below plots our Imatest results at the focal lengths we were able to cover.

The lens-based image stabiliser enabled us to shoot hand-held at shutter speeds down to 1/30 second with the 54mm focal length setting. This equates to approximately one f-stop of shutter speed advantage over an unstabilised lens.

Backlighting was reasonably well handled, although the sensor/lens combination tended to produce silhouettes with high-contrast scenes. However, flare was relatively low, even when the lens was pointed directly towards the sun.

Rectilinear distortion was also quite low, although we observed slight barrel distortion at the widest focal lengths. However, it should not affect normal photography.

The small sensor made it quite difficult to obtain truly out-of-focus backgrounds at wide apertures when the lens was set at the 45mm focal length - and even more difficult at 14mm. Bokeh was attractive, particularly at longer focal lengths.

Buy this lens if:
- It's offered with the camera body.
- You're prepared to shoot raw files.

Don't buy this lens if:
- You can cover the same focal length range with cheaper lenses that perform as well.

IMATEST GRAPHS

SAMPLE IMAGES

14mm focal length, ISO 100, 1/100 second at f/16.


140mm focal length, ISO 100, 1/320 second at f/9.


1:1 aspect ratio; 14mm focal length, ISO 100, 1/100 second at f/13.


1:1 aspect ratio; 140mm focal length, ISO 100, 1/200 second at f/7.1.

4:3 aspect ratio; 48mm focal length, ISO 100, 1/125 second at f/9.


3:2 aspect ratio; 48mm focal length, ISO 100, 1/125 second at f/9.


16:9 aspect ratio; 48mm focal length, ISO 100, 1/125 second at f/9.


1:1 aspect ratio; 48mm focal length, ISO 100, 1/125 second at f/9.

Backlighting: 14mm focal length, ISO 100, 1/500 second at f/13.


Flare: 14mm focal length, ISO 100, 1/250 second at f/18.


54mm focal length, ISO 100, 1/160 second at f/11.


140mm focal length, ISO 100, 1/200 second at f/8.

140mm focal length, ISO 125, 1/200 second at f/10.


100mm focal length, ISO 100, 1/320 second at f/6.3.

Bokeh; 54mm focal length, ISO 320, 1/80 second at f/5.6.


Bokeh; 54mm focal length, ISO 400, 1/30 second at f/9.


Bokeh; 54mm focal length, ISO 400, 1/25 second at f/13.

Picture angle: 75 to 8.8 degrees
Focal length range in 35mm format: 28-280mm
Minimum aperture: f/22
Lens construction: 17 elements in 13 groups
Lens mount: Micro Four Thirds System
Diaphragm Blades: 7 (circular aperture)
Minimum focus: 50 cm
Maximum magnification: 0.2x
Filter size:  62 mm
Dimensions (Diameter x L): 70 x 84 mm
Weight: Approx. 460 grams