Panasonic Leica DG Vario-Summilux 10-25mm F1.7 ASPH
The Panasonic Leica DG Vario-Summilux 10-25mm F1.7 ASPH is a fast zoom lens that covers several popular focal lengths. When mounted on a Micro Four Thirds body, where it’s equivalent to 20-50mm, you can hit 20mm, 24mm, 28mm, 35mm or 50mm with a single lens (and a fast one, at that). It will ship in July for $1799/£1799.
We were able to get our hands on a preproduction lens, so click through to learn more about this beast of a lens.
Big, but not that big
Make no mistake, the 10-25mm F1.7 is a hefty lens, but it’s not nearly as large or heavy as one would expect given its ambitious spec. The lens is 128mm (5″) long, has a max diameter of 88mm (3.5″) and weighs in at 690g (1.5lb). By comparison, Sigma’s 18-35mm F1.8 Art lens is a bit shorter, but almost 20% heavier, despite covering a narrower range of focal lengths.
The 10-25mm is a pricey lens, and it feels like it in the hand. It’s virtually all metal and is dust and splash-resistant. The lens can function down to -10°C/+14°F.
It shouldn’t come as a huge surprise that this ambitious lens requires a lot of glass. The 10-25mm F1.7 has 17 elements in 12 groups and includes aspherical, ED and UHR elements. The lens is threaded for 77mm filters, which serves as an example as how compact (relatively speaking) the 10-25 is.
The lens uses a stepping motor that focuses quickly and quietly.
Grabbing control over focus
The 10-25 is the first Panasonic Micro Four Thirds lens to have a focus clutch, making it easy to quickly switch between auto and manual focus. As you can see from the photo above, the lens can focus down to 28cm (11″).
With the clutch pulled back, the manual focus response is linear. This will be especially useful for video shooters, since it means you can be certain of how much the focus will change in response to you turning the lens. There’s a feedback stop at either end of the focus range but they’re not hard stops: the focus ring will continue to rotate beyond the close and far points, so it’s not great for use with a follow-focus.
Stills shooters are likely to appreciate that it gives an experience much more like an old, mechanically-driven lens,
Put a ring on it
The aperture ring, which travels from F1.7 to F16, is click-less, another feature the video crowd will appreciate. Something we like about the dial, at least on the prototype we used, is that there’s a detent to prevent you from accidentally switching the ring out of Auto mode.
Just as importantly for videographers, the aperture/iris is driven smoothly, without steps. This allows subtle adjustments in exposure (either manually or in auto mode), without the brightness of the video visibly jumping.
No going to great lengths
The lens extends when you adjust the zoom, but not by much: here it’s shown at full-extension.
Its comparably low weight should make it easy for a gimbal to stabilize, and the limited change in length should also mean its center of gravity doesn’t move very much. This should make it possible to get away without having to re-balance for different focal lengths, which is a clear benefit over using a series of prime lenses.
Panasonic released a pair of teleconverters for its S-series full-frame bodies alongside the 10-25mm F1.7. These 1.4x and 2x converters are compatible with Panasonic’s S Pro 70-200mm lenses: the currently available F4 version as well as the F2.8 model coming later this year.
Both teleconverters feature UHR (ultra-high refractive index lens) elements, and Panasonic claims that there’s virtually no reduction in resolution when using them.
The 1.4x and 2x teleconverters are priced at $499/£489 and $599/£579, respectively.