Lens Reviews / Panasonic Lenses i Lab tested

14-140mm	$698 average price

SLRgear Review
November 11, 2013
by William Brawley

The Panasonic 14-140mm ƒ/3.5-5.6 ASPH POWER OIS LUMIX G VARIO is an update to Panasonic's previous compact long-zoom Micro Four Thirds lens, the 14-140mm ƒ/4.0-5.8 ASPH MEGA O.I.S. LUMIX G VARIO HD. This new lightweight compact zoom lens provides a 35mm equivalent field of view of 28-280mm, making it a very versatile single-lens option for Panasonic, as well as Olympus users. This lens is squarely aimed at users looking for a lightweight, compact do-it-all lens for general walk-around use and who don't want to carry lots of additional lenses. The built-in optical image stabilization system makes up for not-so-fast apertures, and helps with low-light situations as well as with video.

The new model has been updated with a stepper motor, redesigned optical formula including 3 aspherical elements and 2 ED lenses, and has Power O.I.S. over the previous model's Mega O.I.S. optical stabilization system that Panasonic claims is twice as effective at steadying large, slow movements. It also features a faster maximum aperture with ƒ/3.5 at the wide end over ƒ/4 in the older model, and ƒ/5.6 over ƒ/5.8 at the long end. Other improvements on the physical side of things include an overall smaller size (with a smaller filter size, as well) and a lighter weight.

Sadly, it's not all good news with this lens, as we ran into a very odd, and repeatable, issue with this lens relating to motion blur caused by the shutter actuation at certain shutter speeds. Despite testing the lens with IS turned off and on a ~250 lb. studio tripod, we observed noticeable motion blurring at slower shutter speeds at the longer focal lengths. See our in-depth explanation further down.

The 14-140mm isn't a ''constant aperture'' lens, in that as you increase the focal length, the maximum aperture sizes decrease. The following table reflects the change in aperture size with focal length:

Focal Length (mm)	14-18	19-25	26-33	34-45	46-68	69-96	97-140
Max. aperture	ƒ/3.5	ƒ/3.7	ƒ/4.2	ƒ/4.5	ƒ/4.9	ƒ/5.4	ƒ/5.6
Min. aperture	ƒ/22 at all focal lengths

The Panasonic 14-140mm ƒ/3.5-5.6 ASPH POWER OIS LUMIX G VARIO is currently available for a price of around $699 and ships with a lens hood, front and rear lens caps and a soft pouch.

Sharpness
When not shooting at vibration-inducing shutter speeds, the new Panasonic 14-140mm lens produces very sharp images. While the new models improves on corner sharpness, the centers did look a bit sharper in the older model, however. It's not a drastic difference, and the new lens is still quite sharp through the entire zoom range, with some softness wide open at the longer focal lengths. At very small apertures like f/16-f/22, we saw a little diffraction-limiting softness come into play, but it's very well controlled. Even stopped down to ƒ/11, throughout the zoom range, it displayed really sharp images.

Chromatic Aberration
This new Panasonic lens actually shows a bit more chromatic aberration compared to its predecessor, although it's only a minor difference, and overall CA is very well-controlled. The amount of CA varies up and down throughout the zoom range, and the new model seems to show the same varied behavior that we saw with the older one. At 14mm and 140mm, we saw a larger difference in average CA (CA visible throughout in the image) and the maximum CA, seen in the corners. At most focal lengths, CA increases slightly as you stop down. Interestingly, at 69-70mm, we saw very low CA, both average and maximum values throughout all apertures.

Shading (''Vignetting'')
With the older version of this lens, we were unable to test vignetting using our software due to a camera issue. We subsequently upgraded our Micro Four Thirds test camera to a Panasonic GX1, and we are able to test vignetting properly with this new camera. Overall, vignetting on this lens is not very severe and fairly average for a long-ratio zoom lens, with the wider focal lengths showing more vignetting when shot wide open. At 14mm, we saw just a little under 0.75 EV of light falloff in the corners at ƒ/3.5, which then quickly dropped to below 0.25 EV once we stopped down to ƒ/8 and beyond.

At focal lengths wider than 97mm, it displayed around 0.25 EV of light loss wide open, and subsequently dropped well below 0.25 EV (think 0.125 EV and less -- barely noticeable) around ƒ/8. At the longer focal lengths of 97mm-140mm, wide open at ƒ/5.6, we saw a little more vignetting in the corners -- around 0.5 EV of light falloff. Vignetting decreased to around 0.25 EV at ƒ/8, but then dropped to near-zero at ƒ/16-ƒ/22.

Distortion
Though not as consistent as the older model, the new Panasonic 14-140mm shows very little distortion. At 14mm, there's a very slight amount of barrel distortion on average (around 0.25%), which is quickly eliminated by zooming to 19mm, where the average distortion is almost zero. The average barrel distortion rises ever so slightly when zooming out to 46-97mm, and then drops off just a bit when hitting 140mm. By comparison, the older model showed a similar amount of barrel distortion between 14-18mm, but then all distortion was completely gone between 18-140mm.

Autofocus Operation
The electronic autofocusing system on this Panasonic 14-140mm ƒ/3.5-5.6 lens is very fast, taking well under one second to autofocus from minimum to infinity focus. The lens is an internal-focusing lens, and the front element of the lens does not extend, nor does it rotate, during focusing.

The high-speed stepper motor autofocusing system allows for focusing to be smoother and nearly silent, which is great not only for stills but for video recording as well. The lens' focusing system is also specially designed to take advantage of Panasonic's high-speed contrast AF system, as found in the GH3 and G6 cameras. Panasonic states that the lens is able to adjust focus up to 240 times per seconds for quicker, smoother focusing.

Manual focusing is also available via a focus-by-wire focusing ring. There's no manual focus switch or focus ring clutch to engage manual focusing -- it's all controlled by the camera body. Even with AF enabled, you still have manual focus override by half-pressing and holding the shutter button and then rotating the focus ring to adjust focus manually.

Macro
Macro performance with lens is quite good (the same that we saw with the previous model), with a maximum 0.4x magnification rating (1:2.5 ratio). The minimum close-focusing distance is 50 cm (a little over a foot and a half).

Build Quality and Handling
This is a very well-built lens that feels quite solid, with a smooth, sturdy telescopic zooming front element. The outside lens barrel feels to be constructed out of metal, though Panasonic doesn't explicitly mention this, and has a shiny black finish. The lens mount is also constructed of metal. The barrel and front element telescope outwards as you zoom to the longer focal lengths, and this interior barrel is constructed of tough, polycarbonate plastic.

In terms of optical construction, this lens has a new optical layout with 14 elements in 12 groups, including 3 aspherical and 2 ED elements. It does however keep a 7-bladed circular aperture that was seen in the older model.

The zoom and focus rings are sandwiched next to each other and are both covered in raised plastic ribs for a nice textured grip. The zoom ring is about 5/8 of an inch wide and is very smooth to rotate with just enough resistance to prevent lens creep and keep the lens zoomed to where you want it. The focus ring is further out from the camera and is about 1/4 of an inch wide. The focus is also very smooth to rotate and easily adjustable with a single finger, whereas you'd need two fingers to rotate the zoom ring. Being an electronically-controlled focusing system, there are no stops to the rotation and the ring will rotate forever.

The lens is otherwise pretty sparse in terms of exterior features. There's a single switch for enabling or disabling the Power O.I.S. image stabilization system. The zoom ring has a series of labeled focal lengths of 14, 18, 25, 35, 50, 70, 100 and 140mm. There is no focus distance window, however. (Depending on the model of camera used, you are shown an approximate distance scale and/or magnified view in the rear LCD or EVF to help with critical focus while manually focusing.)

The included petal-shaped lens hood mounts bayonet-style with a nice, soft-yet-firm click, and the hood extends along with the telescoping barrel. Panasonic has reduced the diameter of this new lens, and it now takes 58mm filters, which attach via plastic filter threads.

Shutter-related Blur Problems
We ran into an issue with this lens related to motion blur at certain shutter speeds on our GX1 test body. When we tested it with Power O.I.S. disabled and on our studio camera stand that weighs over 250 pounds, we found noticeable motion blur at shutter speeds around 1/40 to 1/50 of a second at focal lengths of 50mm and longer. Interestingly, while this blur went away at higher shutter speeds, we noticed that it was also largely eliminated when when we lowered the shutter speed to around 1/15 of a second.

The cause? It turns out that many mirrorless cameras use the same Copal shutter, and the slap of its mechanical first curtain opening can produce a fair bit of vibration within the camera body. Our GX1 test body is one such. Some lenses are more susceptible to this vibration due to how they are constructed or how the lens elements are situated inside the barrel. This precluded us from testing the IS system in this lens, as our our IS shots would have used those problematic shutter speeds and thrown off our IS results therefore we chose not to do an IS test. (While we could side-step the problematic shutter speeds in our normal blur testing, the IS test requires that we shoot at specific shutter speeds which would have included the problematic ones we encountered.)

We first encountered this shutter-related blur issue way back with the original Olympus E-P1; we posted a very detailed analysis of the cause as part of our Olympus E-P1 review, in September of 2009. Depending on the particular lens and body in question, we've seen the same problem (albeit generally to a much lesser extent) on pretty much every Micro Four Thirds camera since then. The range of shutter speeds over which it will occur will also depend on the particular lens and camera in question. With most current cameras and lenses, the effect is generally pretty minor, and as noted below, can be completely eliminated either by using an electronic shutter option (if your camera offers one), or a camera like the GM1, which uses an electronic first-curtain.

We ran some further tests on this new 14-140mm with other Panasonic cameras, notably the GX7 and GM1, which either have shooting modes that only use the electronic shutter (GX7) or only use an electronic first curtain (GM1). As you can see in the table below, the shots using electronic shutter display no motion blur issues, while the mechanical shutter shots from the GX1 and GX7 show vibration-induced motion blur. All of these shots were taken at 46mm at f/4.9 between 1/40-1/50th of a second shutter speed.

Alternatives

Panasonic 14-140mm ƒ/4-5.8 ASPH MEGA OIS LUMIX G VARIO HD ~$850
The most obvious alternative to this lens is the previous model, the Panasonic 14-140mm ƒ/4-5.8 ASPH MEGA OIS LUMIX G VARIO HD. It provides the same focal range and very similar image quality with extremely low distortion, however you do have slightly slower apertures. Oddly, Panasonic is still selling this older lens for a much higher price than the new model -- $850 versus $630 for the new model.

Olympus 14-150mm ƒ/4-5.6 ED M.Zuiko Digital $499
Although it's an Olympus lens, since Panasonic and Olympus share the Micro Four Thirds sensor and lens mount specs, it opens up another avenue for lenses. The Olympus 14-150mm lens offers a very similar focal length range, but a slightly slower maximum aperture on the wide end. It also doesn't have built-in optical image stabilization, and it's not as sharp across the frame as the Panasonic 14-140mm, but it has extremely low distortion and is offered at a slightly lower price at around $499.

Conclusion
The new Panasonic 14-140mm ƒ/3.5-5.6 ASPH POWER OIS LUMIX G VARIO provides Micro Four Thirds users a new option for a compact, long-zoom lens that provides a 28-280mm focal length zoom range in 35mm-equivalent numbers. The new Panasonic 14-140mm ƒ/3.5-5.6 lens is a well-built, lightweight lens with ultra-fast AF and built-in optical image stabilization system. It improves on the variable aperture range of its predecessor with a maximum ƒ/3.5 at the widest end (vs ƒ/4) and at the telephoto end with ƒ/5.6 (vs ƒ/5.8).

For users with a Micro Four Thirds camera like a GX1 that has a mechanical shutter, it's tough for us to recommend this lens given it's strange motion blur issue. However, if you're a GX7 or GM1 owner, then this is a very nice lens to use as you should have no issues with vibration blurriness, thanks to the GX7's electronic shutter mode or the GM1's lack of a mechanical first curtain altogether.

As long as we stayed away from "problem" shutter speeds, the Panasonic 14-140mm ƒ/3.5-5.6 lens still managed to produce sharp photos, though perhaps not as sharp in the center as the previous model. It does however improve corner sharpness noticeably across the entire zoom range. It also does well with chromatic aberration and distortion control, as well as having low vignetting (not completely eliminated but low enough that it's not a big issue).

So, if you're a Panasonic user (or an Olympus user for that matter) who's looking to get a compact, versatile lens for a lightweight "one-camera-and-a-lens" situation, or perhaps a run-and-gun GH3 video shooter, the Panasonic 14-140mm ƒ/3.5-5.6 ASPH POWER OIS LUMIX G VARIO might just be the lens for you. Just keep in mind that shooting at around 1/40-1/50 of a second (even on a tripod!) might introduce some unwanted blur in your photos if you have a Micro Four Thirds camera without an electronic shutter option.

Product Photos

Sample Photos

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