A while back, we talked about the incredible Panasonic Leica 10-25mm f1.7, and we quickly found that it was more than good enough to replace a bag of prime lenses within the 10-25mm range in the micro four thirds format, a lot of which I still consider the best lenses on Micro Four Thirds, including the Panasonic 20mm f1.7 and Panasonic-Leica 25mm f1.4. Albeit, there’s one noticeable difference… size (more on that later).

The Panny-Leica 10-25mm f1.7 was a game-changer. It effectively eliminated the need for the much-loved Sigma 18-35mm f1.8 and Speed Booster combo, giving MFT shooters a native, super-fast zoom in a very useful focal range for both videographers and photographers.

This time around, we see Panasonic and Leica working their magic once more and bringing another potential homerun for the m4/3 system. Is the Panasonic Leica 25-50mm f1.7 a worthy sequel to the 10-25mm f1.7? Let’s see what the pros are saying.

Build Quality and Design

When the news of the Panasonic Leica 25-50mm F1.7 broke, two things were quickly apparent: one it’s a short telephoto zoom follow up to the widely acclaimed 10-25mm f1.7, and two; it’s practically a mirror image of its normal zoom counterpart. The two super-fast zooms share the same chunky diameter of 87.6 mm and 127.6 mm length.

Being made mostly of metal, it’s got some heft to it. The Panasonic Leica DG Vario-Summilux 25-50mm f/1.7 ASPH comes in at around 654 grams. It sits on the heavy side of the scale for sure, but it won’t be as front-heavy as you might have assumed especially when paired with a G9 or a GH5. That and consider the ever reliable weather sealing on optics of this caliber and the insanely bright constant aperture; most pros would be happy to take the weight penalty. One key difference however is that the newer, 25-50mm f1.7 has an internal zoom design which means the barrel doesn’t extend as you zoom throughout the range.

The Panasonic Leica 10-25mm f1.7 was a hit for videographers, and the newer 25-50mm f1.7 continues this trend. A nice treat for videographers and filmmakers is the clickless aperture ring, allowing for smoother exposure transitions while filming.

And if you already own the Panasonic Leica 10-25mm and have been having a blast shooting all of your video projects with it, you’d be happy to know that both lenses have the same zoom, focus, and aperture ring size and spacing. This means that you can just swap the 25-50mm in place of 10-25mm without changing anything on your follow focus rig.

Focus breathing is also “almost invisible” in this lens, according to DPReview TV’s resident director, camera operator, and editor, Jordan Drake. In a nutshell, focus breathing is the phenomenon in which the focal length changes as you rack your focus. For video work, this is a huge deal as you’ll often have to shift your focus during a scene. Panasonic and Leica have done an incredible job at minimizing this phenomenon as much as possible especially considering the fast constant aperture on this lens.

Overall, the Panasonic Leica 25-50mm F1.7 is a premium lens with solid build quality and an optical design that will match its price tag. Check out DPReview’s hands-on review of this fast short telephoto zoom to see how it handles and how it well it suppresses focus breathing:

Image Quality

So the 25-50mm and the 10-25mm look almost identical on the surface. But does it perform anywhere near as good as the first fast normal zoom on the lineup? Does it live up to the 10-25’s reputation and more importantly, is it another “prime killer” zoom in the 25-50mm range?

Fortunately for m43 fans out there, from the initial reports we’re seeing, there’s no question that Panasonic has another winner in their hands.

In terms of sharpness, ePHOTOzine’s lab testing shows the Panasonic Leica 25-50mm f1.7 performing extremely well, at all apertures especially wide open, at the center of the frame all the way to the corners from 25mm to 50mm. Easily prime lens levels of performance right there. The sweet spot seems to be around f2.8 at all focal lengths, and stopping it down further would have little impact in sharpness unless of course you want the larger depth of field.

Portrait photographer Richard Wong’s experience with the lens perfectly lines up with what we’re seeing with the available data. In his video, he pits the Vario-Summilux 25-50mm f1.7 against the Leica 25mm f1.4 and the Leica 42.5 f1.2 Noct. For a bit of context, the Leica 25mm is a favorite standard prime for the m43 community, while the Noct is deemed as one of the best and sharpest lenses for the format.

Spoiler alert: it’s a bloodbath. The 25-50mm f1.7 is so good that the Leica 25mm 1.4 needs to go all the way down to f2.8 just to match the zoom’s sharpness when shot wide open. On the corners, the 25mm f1.4 has to stop down to f4 to match the zoom’s performance wide open.

When compared side by side with the Noct, it’s almost the same story. The 42.5mm Noct needs to stop down to f2.8 just to catch up with the zoom’s level of clarity at f1.7. The Noct does slightly edge out the zoom in the corners, at least at f1.8.

Richard brings up another solid point about the Panasonic Leica 10-25mm f1.7. You see, Panasonic claims that the 25-50mm and the 10-25 share a “unified color rendering.” The claim, according to his testing, holds up really well.

“The images that you shot with this Leica 25-50mm f1.7 lens will look very similar to the photo that you shot with the 10-25mm f1.7 lens. The color, the sharpness, the bokeh from these two lenses will look very, very similar. So when you’re shooting with these lenses side by side, it will give you a more consistent look and image quality, and that could save you a lot of time in post processing.”

Give Richard’s highly detailed review of this lens a look and see how well it fares in the bokeh, chromatic aberration, flare control and vignetting department with some test shots and get ready to be blown away:

Video Performance

Panasonic doesn’t shy away from marketing the 10-25mm and the 25-50mm as the dream lens duo for hybrid shooters. As the pro-grade weather resistance, immaculate image quality and fast constant aperture suggest, it’ll be one of the best pieces of glass you can get for stills.

It’s in the video side of things where the 25-50mm f1.7 will excel far better. As we’ve discussed early on, this uber-fast short telephoto lens has a stepless aperture ring for those smooth exposure level transitions. What we’ve saved for this very section of the article however is what Panasonic calls their “micro-step drive system” which further smoothens out the transitions as you rotate the ring. Here’s a nice little demonstration from Wex Photo Video as to how that looks in the real world.

Focus breathing, as we have established earlier as well, is nearly non-existent. Now a common follow up when the focus breathing issue is raised — is the Panasonic 25-50mm f1.7 parfocal? For new videographers or for folks just learning about videography, a parfocal lens is a type of lens that stays on the area of focus you’ve set it on, even as you zoom in and out. So to clear this out for potential buyers out there, no, the Panasonic 25-50mm f1.7 is not a parfocal lens.

Speaking of focus, the 25-50mm f1.7 performs brilliantly in this department. It features a focus clutch mechanism which, when pulled back, reveals the distance scale on the barrel and engages manual focus mode. In this mode, the focus mechanism behaves almost like an analog, mechanical lens with a linear response (note that it’s still a fly-by-wire system).

In terms of continuous AF on video mode, it’s one of the best Panasonic and Leica has put out. Richard Wong tested the 25-50mm f1.7 with the G9 running on the latest firmware, wide open at 40mm, and as you can see from the footage, it just grabs focus and never lets go as Richard moved around the frame. So if you’re planning to get the 25-50mm f1.7 for a run-and-gun type of shooting, know that it’ll not let you down.

Now what if you’re planning to use it on a “serious” camera for filmmaking, like the Blackmagic Pocket Cinema Camera 4K. Well, Toronto-based director of photography Patrick Tomasso thinks the 10-25mm and the 25-50mm are the only lenses you’ll ever need for the BMPCC4K and the micro four thirds system in general:

“Here’s the deal: If you’re a micro four thirds shooter and even more specifically, a Blackmagic Pocket 4k shooter, I think this 10-25mm and this 25-50mm is a wonderful combination of two lenses, and the only two lenses you’ll ever need for the foreseeable future. I’m just really glad Panasonic has given us these two lenses to last pretty much indefinitely at this point.”

Feast your eyes on Patrick’s cinematic reel using the lens paired with the BMPCC4K:

Conclusion

This incredibly fast, short telephoto zoom performs unbelievably well across the board, beating out even the premiere, Leica 42.5mm Noct in center sharpness. It’s still a pretty fresh arrival and has spent less than a month on shelves, but the initial wave of reviews from pros are nothing but reassuring that this is one of the best pieces of glass you could own for the system.

If you’re the reasonable, GAS-free type of creative and want to wait a little longer before you pull a trigger on an $1800 purchase, then by all means wait till more of the community can pass their verdict on the 25-50mm f1.7. Or, if you’re already shooting with the 10-25mm f1.7, just get the 25-50mm to cover pretty much all of the range you’ll ever need and be set for life.