We don’t need no stinkin’ primes

Micro Four Thirds has a pretty good selection of really neat lenses. Oddly, a lot of those are third-party. It’s nice to see Panasonic and Leica get together to make a couple of really cool lenses. The Panasonic 10-25mm f/1.7 ASPH is one of those lenses.

The Panasonic Leica 10-25mm f/1.7 is an interesting lens. It offers a 20-50mm full-frame equivalent field of view with a fast f/1.7 aperture. It certainly stands a chance at living up to the old “stack of primes” saying. Can this lens replace a few prime lenses in this focal range? I put it to the test on the new Lumix GH6 to find out.

Pro

  • Super sharp throughout the zoom range
  • Manual focus clutch with a good feeling focus ring
  • It’s an f/1.7 zoom!
  • Excellent build quality
  • Weather Sealing

Cons

  • Huge and heavy for Micro Four Thirds
  • Extends and contracts when zooming

Panasonic 10-25mm f/1.7 ASPH — Technical specifications

The following specifications were taken from the B&H product page:

  • 20-50mm (35mm Equivalent)
  • Aperture Range: f/1.7 to f/16
  • Three Aspherical Elements
  • One UHR Element, Four ED Elements
  • Internal Focus, Focus Clutch Mechanism
  • Stepless, De-Clicked Aperture Ring
  • Splash, Dust, and Freezeproof Design
  • Rounded 9-Blade Diaphragm

Panasonic 10-25mm f/1.7 ASPH — Ergonomics and build quality

The Panasonic 10-25mm f/1.7 is built solid. Panasonic and Leica knocked it out of the park. The lens is largely metal and feels hefty and confident in hand. The zoom ring is wonderfully textured. It also turns as smooth as silk. The focus ring is among the best features of the lens. An easy pull back on the ring puts the lens in manual focus. Once there, the focusing feels surprisingly good for a focus-by-wire lens. It won’t beat a pure manual focus lens for feel, but it’s no slouch.

In addition to the excellent feel of the lens, it’s also weather sealed. The line of Panasonic Leica lenses has been built great, and the 10-25mm is no exception. However, the lens does extend when zooming. This could be a potential point of weakness in the sealing. It also can make gimbal use a bit of a pain. With that in mind, I have used the Panasonic Leica 12-60mm for over a year without issue and it also extends while zooming.

Panasonic 10-25mm f/1.7 ASPH — In the field

The Panasonic 10-25mm f/1.7 is an easy lens to get along with. There are no switches to fumble with, just the excellent zoom and focus rings. It’s not stabilized, but with the Micro Four Thirds camera’s great IBIS, there’s no need to worry. This lens is plug-and-play. Just slap it on your camera and go enjoy.

Panasonic 10-25mm f/1.7

One thing worth noting is its bulk. This thing is a chunk. It feels similar to a full-frame Sigma Art 24-70mm lens. With a weight of 1.5lbs, it’s certainly heavier than other lenses for this platform. It’s also quite large. Above is a photo of it next to my Canon RF 24-105mm STM and Canon EF 50mm f/1.8 for scale. However, when mounted to the GH6, I found it manageable. It seems like a reasonable price to pay for an f/1.7 zoom lens.

Panasonic 10-25mm f/1.7 — Autofocus performance

The Panasonic 10-25mm f/1.7 is one of the select few that can handle autofocus in higher frame rate video modes on the new GH6. This lens is blazingly fast. Point to point AF in single focus is great. Continuous autofocus performance is sticky and quick as well. It had no trouble keeping up with dogs, mountain bikers, and more on the GH6.

However, the Panasonic pulse is still going strong. In shooting stills, it’s mostly just an annoyance learning to trust the camera. Seeing the wobble in the EVF can be disconcerting. For video, it’s more of a problem. It shows its ugly face when using continuous AF during video recording.

Also, it’s worth noting that the minimum focus distance with the Panasonic 10-25mm f/1.7 is excellent. It’s able to focus incredibly close at 11.02 inches. At 25mm, this gives a pretty nice reproduction ratio. Just as importantly, it’s sharp at the minimum distance as well.

Panasonic 10-25mm f/1.7 — Image quality

It’s hard to fault the Panasonic 10-25mm f/1.7 when it comes to image quality. Panasonic and Leica have built a whopper of a lens. Let’s break down the image quality further.

Ghosting, flaring and chromatic aberrations

Overall, the Panasonic 10-25mm f/1.7 handles shooting into and across the sun quite well. It has minimal issues with flaring and ghosting. However, I was able to get purple and green fringing to show up in extreme situations. In the tree photos above, one shows purple, the other shows green in slight amounts. However, in most situations, I didn’t notice any chromatic aberration. Contrast also seems to hold up well when shooting toward the sun.

Sharpness

The Panasonic 10-25mm f/1.7 is razor-sharp. This lens can more than hold its own. On the GH6’s 25-megapixel sensor, I put this lens to the test. It even delivers beautiful detail in the 100-megapixel high-resolution mode.

From f/1.7 the lens is crispy sharp in the center, with only a mild falloff in sharpness in the corners. By f/2 it’s bitingly sharp across the frame. This stays excellent up to about f/8. Afterward, diffraction starts to set in. Overall, it delivers an impressive performance.

Bokeh

While the Panasonic 10-25mm f/1.7 is a wider zoom, it is capable of some nice background blur. When you get to around 15mm-25mm, with appropriate distances, this lens does produce some nice bokeh. It’s rendered smoothly and without busy distracting elements.

Specular highlights (aka bokeh balls) stay mostly nice and round. There’s no major cat-eye effect or onion ringing. The highlights stay nice and smooth as well. For a lens of this type, it delivers some nice bokeh.

Color rendition

I found the color that the Panasonic 10-25mm f/1.7 produces to be a touch on the cool side. However, that lines up well with most of the Panasonic Leica lenses I’ve used. Overall, the colors are nice and neutral. I found that the lens renders nice contrast as well. The images in this review are either JPEGs out of camera, or lightly edited RAW files. In the RAW edits, I didn’t have to mess with the color at all.

Panasonic 10-25mm f/1.7 ASPH — A killer zoom for Micro Four Thirds

I’ve been looking forward to getting my hands on the Panasonic 10-25mm f/1.7 for a while now. I’m happy to say it didn’t disappoint. There’s finally a native Micro Four Thirds lens to take the place that the Sigma 18-35mm f/1.8 on a speed booster used to fill. This lens does everything well. From portraits to action to landscapes and architecture, I enjoyed putting it through its paces.

For video shooters, it’s an even more appealing option. The manual focus clutch is excellent. The focus throw is natural feeling and blows many of the other focus-by-wire lenses I’ve used out of the water. The only real downside to this lens is its considerable size and weight. If you can deal with that, however, this lens is certainly one to consider adding to the collection.

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