Sunday, 9 September 2012

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 14-42mmLumix G 14-42mm
Number of aperture blades77
Lens elements912
Lens group89
Exotic elements4 asph, 2 ED1 asph
Minimum focus distance0.2m0.3m
Maximum magnification0.34x0.16x
Weight95g165g
Diameter61mm61mm
Length27mm64mm
Filter thread37mm52mm


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 14-42mmLumix G 14-42mm
Minimum focus distance @ 14mm0.2m0.3m
Minimum focus distance @ 42mm0.5m0.4m

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 14-42mmLumix G 14-42mm
Focus delay @ 14mm0.14s0.24s
Focus delay @ 42mm0.40s0.28s

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.


20 comments:

  1. I have the 14mm, the Lumix G 14-42mm f/3.5-5-6 and the Lumix X 14-42mm f/3.5-5.6 (two actually) and I find that the 14mm prime outshines the zooms in terms of quality and even pocketability (slight less weight and size). But the zooms are useful in certain circumstances and the marginal picture quality in most circumstances means that the 'X' has to be the winner. But I'm saving up for the Lumix 20mm prime and a nice portrait lens (~80mm).

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  2. What could be a maximum size of a step-up ring to be within limits of an extending barrel's diameter. Could you be kind to measure the maximum diameter of the extending barrel...

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    1. The extending section has a diameter of 52mm.

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    2. Can you give us a thought about the difference in sharpness between the 14-140 (with in the same focal range) and in comparising with the 12-35/2,8.

      You should be very helpfull.

      Jos

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    3. The Lumix G HD 14-140mm is probably comparable with the Lumix X PZ 14-42mm in terms of sharpness: Neither are very sharp.

      The Lumix X 12-35mm is in a totally different league: It is very sharp.

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    4. Thanks, but I have made a mistake i have asked the wrong question!

      Please can you give a thought about the difference between the 14/40 and the PZ X 45/175 in terms of sharpness?I like a lot of words?

      Jos

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  3. In your comparison of the 14mm pancake to the 20mm f/1.7, you emphasized how outstanding the 14mm is for outdoor video, that it held focus well. Here, in the conclusion, you sound like you have "moved on" from carry the pancake around, replacing it with this PZ lens as your go-to for wide, and also mentioning how the power zoom and OIS are useful for video specifically. Does that imply that this 14-42 PZ lens compares well enough to the 14mm pancake in holding video focus that it has made the latter largely superfluous for you?

    While asking the question, let me take the opportunity to thank you for this blog, it has been incredibly helpful in bringing me a little more up to speed with what, how, and why of the 4/3 world. Your content admirably covers the range from basic concepts to extremely specific comparisons & tradeoffs. I only discovered it yesterday, but have already spent at least three hours reading & browsing here, and expect to back frequently!

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    1. p.s. I also just saw that in your "FAQ" blog entry of June 2012, the first entry, "What is your favorite lens?" lists the 14mm pancake as one of the two that you carry with you most often. So would it be reasonable to conclude that the 14-42 PZ must actually be a really appealing lens for you, to have dropped your old standby in favor of it just three months later? I'm just trying to reconcile your conclusion with the rest of the review, which comes across as not very enthusiastic, and I'm examining your reasoning so closely because I really value your opinion, not trying to nitpick for it's own sake! thanks again.

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    2. In my opinion, the Lumix X 14-42mm is a very interesting lens, with an impressively compact zoom mechanism. It's a technological marvel, to cram all this features into a small package, with OIS included.

      Still, I'm not that attracted to it. I think the image quality is simply not that convincing. The bokeh is far from optimal, and the sharpness is surpassed by the cheaper Lumix G 14-42mm f/3.5-5.6.

      As I mention in this blog, I have brought it along from time to time due to its compactness, when I would previously have brought along the Lumix G 14mm f/2.5. However, at then end of the day, I still prefer the 14mm lens, due to its better image quality.

      For flexibility, the X 14-42mm wins, but for image quality, the 14mm prime lens wins. Out of the two, the 14mm prime lens is still my favourite.

      For yourself, I think you should consider what you want. If you are used to having a zoom lens, and a range of focal lengths available at hand, then you might find the Lumix G 14mm f/2.5 limiting. After all, it is only a wide angle lens. Nothing wrong with choosing a zoom lens for the flexibility, in my opinion.

      To top this off, there is a new basic kit lens coming, the Lumix G 14-42mm f/3.5-5.6 II. That lens is more compact, but still larger than the Lumix X 14-42mm f/3.5-5.6. So far, reports indicate that it is rather good.

      It's interesting that you have noticed these inconsistencies. While I update old posts from time to time, to keep them up to date, I generally don't change the discussions like the one in the conclusion above. So while my experience grows, I guess it's inevitable that the conclusions will change also.

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    3. Thanks for the quick reply Fredrik! Yes, shortly after I posted my questions, I found the announcement of the "II" zoom, with hint it'd be included with the G5 (an possibly other bodies) as a kit. The press announcement was dated January, so I hoped it'd already be out, but it does not seem to be (except for one ebay auction from a Taiwan seller for $339). I did find an early, favorable reviews/preview, dated March 13, so hopefully not long:

      http://www.ephotozine.com/article/panasonic-lumix-g-vario-14-42mm-f-3-5-5-6-ii-lens-review-21563

      I am starting to suspect this will be part of the new models/kits they announce on 4/9. FYI (for benefit of others searching for it) the model # is H-FS1442A.

      It's perfectly understandable your opinion will change! Otherwise we'd all be using Canon/Nikon manual SLRs :) My own opinions are going through a rapid evolution, over the course of just a few days. I used a pre-digital SLRs when I was young, but maybe lost interest because of both the delay in feedback -- you'd try something, but have to wait a day or two to get the film back from the developer to see how it worked -- and of course getting it developed consumed time & money. But now I find myself sometimes chafing at the limitations even of a wonderful P&S camera (Lumix DMC-ZS7), so I thought maybe I was ready to try non p&s again. When amazon had a deal on the GF3 w/ 14mm pancake for $270 I jumped on it, thinking (as much as I ddi think it through) it'd be a nice "bridge" to start stepping out of the P&S world, and that eventually I'd get a second, more capable body, and larger lenses. But having had it about 48 hours now, taking random shots in all kinds of circumstances, I am coming to conclusion that the reason I bought it is actually a problem -- it might be too *little* a step from my ZS7 -- and that I should get something like a G5. Especially having an EVF & better ergonomics, plus the movable LCD seems very useful for video. Shooting so much with the GF3 the last couple days has reminded me of one of the most annoying things about digital P&S cameras: you can't see the LCD in bright sunlight, especially with snow! So now I'm backing up and coming at it from the opposite approach; I'll return the GF3 & get a larger, more capable and ergonomic body to start with (hopefully with this new zoom in the kit), and keep using the ZS7 as a "not planning to shoot but I'll stick it in my pocket just in case" camera. Then, if my interest in 4/3 does take root, only then maybe I'll look for a GF3-like camera to supplant the function of the ZS7. I can still see getting the X 14-42mm in that scenario (especially for video), but I need not be in such a rush to stop using the ZS7.

      Anyway, that's where I'm at now; probably will be thinking something entirely different 24 hours from now! -; Thanks again for the thoughtful reply!

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    4. I've used the GF3 as well, and I think the ergonomics are rather poor. Panasonic appear to have realized the same thing, as the GF5 improves upon this by adding a rubber grip to the front.

      The G5 looks like a much more capable camera. The grip, the EVF and the articulated LCD mean that the camera becomes bigger, but these are the features that I like anyway. The G5 is due for a replacement soon, but at this time, it appears to give a quite good value for money.

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  4. I bought one of these years ago and I find that distance phot's are terrible all blurred nothing good over 5 metres- is that is what is expected from this camera

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    1. Ummm ... this lens that you bought "years ago," has in fact only been on the market less than two years! lol

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    2. Are you sure that you are correctly focusing on the distant background? Try to take an example picture where there are no near objects in sight whatsoever, only far away.If you have autofocus enabled, those should come out sharp.

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  5. Har du fått sammenliknet den gamle og den nye utgaven av Panasonic Lumix G 14-42mm F3.5-5.6?

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    1. No. But as I understand, the new is better, however, it has a slightly smaller aperture through the zoom range.

      If given the choice, I would go for the new one.

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  6. Not sure why you fortgot to mention this, but at the test with the wooden plank it shows that the X version is sharper at f5.6 and 8.

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  7. I'm total noob so my question might sound silly but is it possible to extend zoom of power lens by adding an attachment like this to x power zoom 14-42mm lens : http://goo.gl/un5DSM ? If I understand correctly it should be attached on top of it and will extend the range? I'm not a professional photographer and chose camera with power zoom as I expect better quality than my previous ultrazoom point and shoot from 4/3rds but it seems I'm going to miss having decent zoom. I don't want to buy fancy telephoto lens but I'd buy something inexpensive just to extend the range. Thank you very much for your advice in advance.

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    1. No, that extender is not going to work. It has a 52mm thread, while the Lumix X 14-42mm lens has a 37mm filter thread.

      Also, I would not mount a long, heavy extender to the power zoom lens. It would most likely damage the motor zoom mechanism.

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    2. Thank you, Fredrik for advice. So I guess I'll have to listen to my wife's complaints for a while (she doesn't care about lenses as long as she can point and shoot and have good pics :D ). $300 and up for lens is way out of my budget at the moment.

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