LEICA DG VARIO-SUMMILUX 25-50mm F1.7 ASPH (H-X2550)

The 50-100mm equiv focal range makes this lens ideal for interview situations

The 25-50mm focal range is the equivalent of 50-100mm in a full frame system, so offers standard to mid-telephoto views that will be useful for general work as well as intimate portraiture, product work and events. Videographers who have the choice of full sensor or pixel-by-pixel recording can also make this focal range produce the effects of a 65-130mm lens in 4K or a 135-270mm in FHD, so it offers an amazing amount of flexibility.

With an almost identical design the Lumix 10-25mm and 25-50mm Leica DG Vario-Summilux lenses make a perfect set

This new lens is the second in a series of fast constant aperture Leica zooms in the Lumix G range, and sits perfectly alongside the existing Leica DG Vario-Summilux 10-25mm f/1.7. The two lenses have a great deal in common, so the extent that you have to look twice to check which is which. This mirroring of design makes the lenses easily interchangeable in video rigs and on tripods without the need for extensive adjustments, and Panasonic has been careful to match up the positions of focus and aperture rings too. Though not as perfectly aligned as the new f/1.8 series for the Lumix S cameras, these are close enough that in most cases follow focus equipment won’t need shifting when the lenses are changed.

The large front element of the lens allows lots of light to enter so it can offer its f/1.7 constant maximum aperture

The pair both use a 77mm filter, so filter holders and lens caps can be switched easily between the two, and as they are much the same length matt boxes also won’t need much adjustment. While the 10-25mm lens has some movement in the front section as the zoom ring is turned, the new 25-50mm lens stays completely still as it goes through its focal lengths.

Pulling down the focus ring reveals manual focusing markers

Although most users will operate this lens in autofocus mode, the lens provides a pull-down feature on the focusing ring that reveals a manual focus scale. In either position the focusing ring continually rotates, but in the down position it takes a turn of about 55-60° to shift us from the closest focus to infinity.

The size and weight of the lens makes it an ideal partner for the new Lumix GH5M2 as well as the existing GH5

At the 25mm end of the zoom closest focus is 28cm, while at the longer end it’s 31cm. Pulling the focus ring into the manual focus position automatically triggers the MF Assist feature in the camera which will, by default, magnify the area under the focus point – though of course you can choose whichever MF assist function you want.

In the A position the aperture can be controlled via the camera body, like all Lumix lenses. This model though also offers a manual aperture ring with de-clicked positions

The aperture range of the lens runs from f/1.7 to f/16, and the iris uses 9 blades to ensure out-of-focus highlights are nicely rounded and focus transitions are smooth and attractive. The iris uses a micro-step drive system so that automatic aperture adjustments made while filming don’t appear jerky and remain unnoticed other than the change in depth-of-field. The aperture ring is also de-clicked, so adjustments to the iris during filming won’t disturb the audio track.

Of course, while a very useful lens for videographers the 25-50mm Leica DG Vario-Summilux f/1.7 is an excellent choice for stills photographers and sits very comfortably on the Lumix G9

Placing an aspheric element in the centre of the lens construction helps to reduce spherical aberrations but also reduces curvilinear distorts throughout the entire zoom range. This also helps to eliminate shifts in the shape of the subject as the focal length changes as well as magnification adjustments while focusing, so ‘breathing’ should be minimal.

While this is a large lens it remains remarkably lightweight at 654g – about the same as the Leica DG Vario-Elmarit 50-200mm f/2.8-4

There are 13 elements in the lens design, including a single aspheric, three Extra-low Dispersion elements to reduce chromatic errors, and one Ultra-High Refractive element that helps to keep the lens as small as possible. Ten gaskets and seals around moving rings and front and rear elements keep out dust and moisture.

The lens hood that comes included with the lens measures approx. 63mm deep and features a press-button lock.

The Leica DG Vario-Summilux 25-50mm f/1.7 Asph comes with a dedicated lens hood and a draw-string tough bag to protect it. The hood reverses over the forward part of the lens to help shield the lens during transit and to keep the whole set-up as compact as possible.

A tough double layered draw string bag is included to protect the lens in transit and in storage