Lumix X PZ 14-42mm f/3.5-5.6 Review: Compact, but not the best image quality

The Panasonic Lumix G Vario X PX 14-42mm F3.5-5.6 Power OIS is a kit zoom lens in a very compact form factor. It collapses when not in use, in which case it is about the size of the Lumix G 20mm f/1.7 pancake lens.

Both the zoom and focus are the "fly by wire" type, meaning that they can only be operated through levers on the side. This has both positive and negative aspects: The power zoom (PZ) enables smooth zooming during video. For still image photography, though, I would say that a mechanical zoom ring is more useful than the lever operated power zoom.

When looking at this lens, it is natural to compare it with the Lumix G 14-42mm f/3.5, the more basic kit lens. They are both pictured below:

In the foreground: Lumix X 14-42mm (left) and Lumix G 14-42mm (right). In the background: Lumix X 45-175mm (left) and Lumix G 45-200mm (right).



First, let's look at the specifications:

	Lumix X PZ 14-42mm	Lumix G 14-42mm
Number of aperture blades	7	7
Lens elements	9	12
Lens group	8	9
Exotic elements	4 asph, 2 ED	1 asph
Minimum focus distance	0.2m	0.3m
Maximum magnification	0.34x	0.16x
Weight	95g	165g
Diameter	61mm	61mm
Length	27mm	64mm
Filter thread	37mm	52mm

Based on the specifications alone, the lenses appear similar: They have the same focal length range, aperture range, and the newer X lens even sports a shorter minimum focus distance. However, be aware that these figures are a bit deceitful. Let's start with the aperture range. While the end points are the same, f/3.5 in the wide end and f/5.6 in the long end, the range between is very different. It can be summarized with this diagram:

This tells us that the newer Lumix X 14-42mm collapsible lens has a smaller maximum aperture for all intermediary focal lengths between the wide and long end. It reaches f/5.6 already at f=32mm, while the older Lumix G 14-42mm lens reaches f/5.6 at f=42mm, the longest end. At f=25mm, the difference is about 1/3 stop. This is not a very large difference, but it shows that in terms of aperture, the newer X lens generally gives you a smaller aperture opening.

Another specification item which is quite misleading is the minimum focus distance. From the table, the newer X lens has the shortest minimum focus distance, which looks all well. However, this applies only at f=14mm, and the distance changes in tele mode:

	Lumix X PZ 14-42mm	Lumix G 14-42mm
Minimum focus distance @ 14mm	0.2m	0.3m
Minimum focus distance @ 42mm	0.5m	0.4m

Generally, one gets the largest magnification in the longest tele setting. However, in this case, the older Lumix G 14-42mm lens has the shortest focus distance at 42mm, which would enable you to photograph smaller images at 42mm with the older lens.

Physical appearance

The outer barrel of the lens is plastic. There are two levers on the side, one for focus, and one for the power zoom:

The levers operate very smoothly, and have a high quality feel. The lens mount is metal, unlike the older Lumix G 14-42mm lens, which has a plastic lens mount. Personally, I don't think this makes any difference for small lenses like this. But the metal mount generally makes people feel more confident with their lens.

When extending the lens, the inner barrel is exposed. This barrel is made of eloxed aluminum. When extended, the inner barrel is very stable, it feels solid with no play at all:

The lens extends when you turn on the camera. The extension takes two seconds. Hence, there is always a two second delay before you can use the camera. This is of course not a lot. The Sigma 30mm f/2.8 EX DN, for example, has a start up delay of three seconds, even though it has no extending section at all.

If you accidentally turn on the camera while it is in a bag, with no room for the lens extension, then the camera notices this, and gives up, leaving the lens unextended. When entering power save mode, the camera will collapse the lens. This is perhaps a bit counter intuitive, as it needs to extend again before being ready after waking from the sleep mode.

Finally, if you connect the camera to a computer, and turn it on to transfer files using the USB cable, the lens will extend, even when the camera is in file transfer mode.

The rear exit pupil of the lens is stationary, even when the lens extends, and during zooming. This is contrary to the older Lumix G 14-42mm f/3.5-5.6 lens, in which the rear element moves forward when zooming in. One could speculate that the Lumix X 14-42mm lens does not create any dust problems when zooming, as the rear element, facing the sensor, is not moving back and forth at all.

Hood

No hood is supplied with this lens. I guess a hood would defy the purpose of the lens, which is to be very compact. I still prefer to have some small, simple hood on my lenses, so I used a 37mm stand off ring:

This probably doesn't do much in terms of keeping out stray light, but it makes me feel safer when I handle the lens, as there is some protection against objects touching the front lens element accidentally. This solution does not add any unwanted vignetting.

Autofocus speed

I tested the focus speed of both lenses by turning on the camera, a Lumix GH2, and then seeing how long time it takes for it to lock on a subject 0.5m away. The lightning was at around 11 EV, quite bright. I did the test at 14mm and 42mm:

	Lumix X PZ 14-42mm	Lumix G 14-42mm
Focus delay @ 14mm	0.14s	0.24s
Focus delay @ 42mm	0.40s	0.28s

You can see the test here:



One could say that this test is a bit unfair towards the newer X lens. Usually, you will see that the focus speed goes down quite a bit when working in the boundaries of the focus distance range. And the Lumix X lens is at the very closest focus distance possible at 0.5m, while the older Lumix G lens still has some margin down to its closest focus distance at 0.4m.

Overall, I'd say the focus speeds of the two lenses is quite comparable. Most kit zoom lenses focus very fast anyway, and for still images, the focus speed is rarely any problem with them.

Manual focus

Manual focus is operated with the focus lever on the side, given that you select the manual focus mode on the camera. This works ok, although it must be said that a real focus ring is much easier to use. I suppose that most users will use autofocus most of the time, so I don't see this as an issue. The focus lever gives you two different focus speeds, depending on how hard you push the lever.

Power zoom

Just like the Lumix X PZ 45-175mm f/4-5.6 tele zoom lens, the Lumix X PZ 14-42mm has power zoom functionality. Unlike the 45-175mm lens, though, the 14-42mm only has the zoom lever, not the zoom ring. This makes the zoom a bit more awkward to operate, in my opinion.

Using the zoom lever, you can operate the motorized zoom at two speeds. These are selectable by pushing the lever more or less hard, just like with the motorized manual focus.

Here is a video which illustrates the use of the Power Zoom feature:



The power zoom feature works well. Personally, I would have preferred to have a zoom ring, but I can see why they chose to put a zoom lever: To save space. And the compactness is one of the key features of this lens.

With some experience and dexterity,  the lever control allows for very precise control of the focal length. For example, there are several intermediary stops possible between 14mm and 15mm focal length.

Image quality

Here is an example image, taken at 14mm with both the 14-42mm lenses. The focus distance was about 0.5m, with the focus area set on the centre of the wooden plank:

Here are 100% crops from both lenses to compare the quality:

This test shows that both lenses have quite good image quality in the centre. The X lens, though, exhibits some quite bad donut shaped bokeh, which is not lost until stopping down well beyond f/5.6.

Here is a rather simple test at f=42mm. Again, the focus distance was about 0.5m:

And here are 100% crops from the upper left corner of the frame:

This test shows that the older Lumix G 14-42mm lens is in fact significantly better in the corner at 42mm. This doesn't surprise me, since I have previously been impressed by the basic kit zoom lens.

In the centre, they are very similar, though.

Here you can find a comparison with the Sigma 30mm f/2.8 at 30mm. As you would expect, the Sigma lens is significantly better. After all, it is a prime lens with a moderate aperture.

The image quality leaves something to be desired for this lens. The bokeh can be problematic, and the image quality is not the best in the corners.

Regarding flare, I have often seen the lens handle high contrast situations poorly, especially when using longer focal lengths. Perhaps a proper hood would help.

Geometric distortion correction

Just like most other Micro Four Thirds lenses, this one relies on in-camera geometric distortion correction to show rectilinear results. My tests indicate that the lens gives barrel distortion in the short end, and pincushion distortion in the long end, quite common for such a lens. With the correction, though, there is little residual distortion.

Example pictures

This image was taken at 14mm, f/5.6, 1/320s, ISO 160:

With some 100% crops from the image:

Another example, taken at f=35mm, f/8, 1/320s, ISO 160:

With some 100% crops from the image:

Example video

This was video recorded using the GH2 camera, in 1080p 25fps, auto everything. The camera was hand held, and the focal length was mostly at 42mm, however, I zoomed a bit out some times using the power zoom.



In this article, you can find a video recorded mostly at 14mm, including some use of the power zoom feature.

Conclusion

The main attraction of the Lumix X PZ 14-42mm f/3.5-5.6 is the size. It is remarkably compact, and as such fits well into the Micro Four Thirds concept. The image quality is good, but not stellar.

Previously, I often put the Lumix G 14mm f/2.5 pancake lens in my pocket when I wanted to have a spare lens in case I needed to go wide. Nowadays, I often bring the Lumix X 14-42mm f/3.5-5.6 for that purpose. It is not much larger, and adds OIS, which is useful for video, as well as the option to zoom in to 42mm. I believe the image quality of the 14mm pancake lens is probably better than that of the Lumix X 14-42mm lens, but the latter adds a lot of flexibility, with a zoom and OIS.

Compared with the older and cheaper Lumix G 14-42mm f/3.5-5.6, I would say that the cheapest lens is the best when evaluating the image quality exclusively. So if you don't care about size, and don't need the power zoom, I'd say get the Lumix G 14-42mm f/3.5-5.6.

For me, the size matters, and I am tending to use the Lumix X 14-42mm f/3.5-5.6 mostly these days. The power zoom feature does come in handy when video recording, I must say, so it adds to the usefulness of the lens.

I'd say that this is a lens you would buy for the ultimate in compactness, not to get the best image quality.