Conclusion

The Panasonic Leica DG Vario-Summilux 25-50mm F1.7 ASPH is an optically outstanding, outrageously fast lens that will particularly appeal to videographers thanks to its killer combination of a de-clicked aperture ring and focus clutch mechanism with linear manual focusing.

With stellar performance throughout the aperture and focal ranges, it could conceivably replace a number of prime lenses in your camera bag, such is the optical quality on offer.

It is undeniably large and heavy, though, being much better suited to life on larger Micro Four Thirds camera bodies like the Panasonic GH5 II that we tested it with, and the clickless aperture ring is less convenient for stills shooters who want to quickly set a specific aperture (although you can switch this setting to the camera body if you'd prefer).

The Panasonic Leica DG Vario-Summilux 25-50mm F1.7 ASPH zoom offers a rather unique focal range of 50-100mm, covering everything from "standard" 50mm shots to moderate telephoto, and as such it proved to be a very versatile walkaround lens.

There's some noticeable vignetting, particularly at 25mm, but otherwise it delivers fantastic sharpness at virtually all focal lengths and apertures, even right at the edges of the frame, and distortion and chromatic aberrations are very well controlled too.

Build quality is very good, to be expected given the premium price-tag, and the fact that this lens is weatherproof is the icing on an already rich cake, although note that Panasonic do stop short of calling it fully weatherproof.

Price-wise, it's best to judge the Panasonic Leica 25-50mm as a viable alternative to buying several other prime lenses, rather than just being a single zoom lens that happens to cost a whopping £1,799.99 / $1,799.99. You could just invest in the 25-50mm and not have to worry about having to buy any more lenses in that focal range, it's that good.

In summary, the Panasonic Leica DG Vario-Summilux 25-50mm F1.7 ASPH is a unique, versatile and optically outstanding lens that is a must-buy for pro videographers and seriously tempting for everyone else.

Ratings (out of 5)
Design	4
Features	4.5
Ease-of-use	4.5
Image quality	5
Value for money	4