Saturday, 13 November 2010

Panasonic Lumix G 14mm f/2.5

The Panasonic Lumix G 14mm pancake lens is the long awaited miniature standard wide prime. Some people have been disappointed by the aperture: The max aperture is f/2.5, which is a tad slow for primes. On the other hand, it is clear that size was important when designing this lens, and a moderate max aperture is needed to design a small lens.

To further reduce the overall size, it comes with new slim line, low profile front and rear lens caps:


Here you see the lens without the front cap:


Hood

No hood is supplied with the box. I like to have a hood on my lenses, for protection against objects touching the front lens element, as much as protection against stray light. To get some basic protection, while retaining the compact size, I have put a 46mm stand off ring on the lens.

A 46mm stand off ring is a bit uncommon, and might even be expensive to buy. So to avoid this, I simply ordered one of the cheapest UV filters from an auction site, and removed the glass. I did this by unscrewing the inner ring which holds the glass:



The filter cost less than US$5, so it is not a huge investment. If you're unable to unscrew the ring that holds the glass, you can just break it. But be careful, so you don't harm yourself.

Here you have the lens with the stand off ring mounted:


Mounting this ring does not add any extra vignetting to your images.

You could also put the 46-37mm step down ring on the lens, and use it as a hood. It does not cause vignetting on the 14mm wide angle lens. But you'll need to buy a 37mm front lens cap as well. They are usually not as slim as the supplied 46mm hood, hence the lens will take up more space in your bag in this configuration. It is still very tiny, so I don't think this would be an issue.

Here is the lens with the 46mm-37mm step-down ring added:





On the camera

When mounted on the GH1 camera, the lens looks hideously small. Not that I mind, though. I much prefer compact lenses to large ones, as long as the image quality is good enough.


Autofocus

This lens uses a different focus mechanism compared with the Lumix 20mm. Whereas the Lumix 20mm lens uses a traditional focus method, in which the whole lens assembly moves back and forth, the newer Lumix 14mm lens has internal focusing.

The advantages with internal focusing are apparent: The elements that need to be moved are smaller, hence, they can be moved faster, more quietly, and using less energy. Also, the front of the lens does not move at all, which makes the lens more rigid, and less prone to water contamination.

In use, it is immediately apparent that the autofocus is faster than the Lumix 20mm. My examination reveals that it is about twice as fast. Still, it is not as fast as the HD rated Lumix G HD 14-140mm superzoom lens.

The aperture still makes some noise when it changes. But it's not a problem in most cases. As long as the shutter makes even more noise, you don't notice it much. But when shutterless cameras become common, you might recognize the aperture noise to a larger degree.

Sharpness

The Lumix 20mm is known for it's good sharpness even wide open. So I'm sure a lot of people are curious if the 14mm is as sharp.

My experiment shows that the 14mm lens is as sharp in the centre, but could be slightly less sharp in the corners. However, both lenses are very capable.

Here's the common "foliage against the sky" test of the sharpness (click for larger images):

f/2.5, 1/125, ISO 160
f/5.6, 1/25, ISO 200

I left the camera at auto exposure, which appears to have given slightly different exposures.

To better evaluate the sharpness, let's look at 100% crops from the images (click for larger image):



The sharpness appears to be good from the largest aperture. There is some purple fringing in the centre at f/2.5, but not much. In the corners, there is still purple fringing when stopping down to f/5.6, but this is not really a big problem.

We can also see that there is some vignetting in the corners at f/2.5, but it is completely gone at f/5.6. This is not the best comparison for vignetting, since the exposure appears slightly different in the two pictures. But you can see that the sky is darker in the corners, compared with the centre, in the picture taken at f/2.5. I'd say this vignetting is to be expected with such a small lens and small front element. I wouldn't worry too much about it.

Here's another look at the sharpness and bokeh of the lens.

Bokeh

I have made this study of the bokeh during daytime (low contrast), and this during nighttime (out of focus highlight in the background).

The first study does not reveal any problems with the bokeh. The second test, during nighttime, and with high intensity lights in the background, reveals that the bokeh is somewhat "dirty" and "swirly", and has some ringing. Put another way, the bokeh is not optimal.

On the other hand, you are not very likely to experience the unpleasing bokeh during normal real life use of the lens. Say you take a picture of people. To avoid distortion of the faces, you'll want to keep a distance of about 1 meter or more. At this focus distance, the out of focus rendering is hardly noticeable, even at f/2.5, due to the wide angle property of the lens. So don't worry about the bokeh.

Chromatic aberrations

I have made a study of the chromatic aberration (CA) artifacts of this lens, and some other prime lenses. It shows that there are some quite small red/green fringing artifacts in the corners of the frame, but it is effectively corrected by software.

All the example images on this page are from the out of camera JPEG images, which have been adjusted for CA artifacts. Panasonic Lumix G cameras automatically apply this correction when it produces JPEG images, and it is also done by some RAW conversion programs.

Even before this correction, the artifacts are not very annoying. So users of Olympus cameras, which to date do not apply this correction, should not find this a big problem.

Example image

The image was taken using f/4, 1/8s, ISO 640. I held the camera against a hand rail for some support during the long exposure.


And here is a 100% crop from the centre of the image. It has not been sharpened:


And here is a 100% crop from the top left corner area:


Example videos

Low light video with some action using the Lumix G 14mm f/2.5 pancake lens on a GH2:



More information about the video parameters used in the movie above. You'll notice that the audio quality is poor in the video. However, this is due to the sound system, which clips the sound at high levels.


This video showing the ice breaking up in Stockholm was recorded using a Lumix G 14mm f/2.5 pancake lens on a GH2, at 1080p, 24fps:




More information about the video and the image parameters here.

Distortion correction

Just like a host of other Micro Four Thirds lenses, the Lumix 14mm pancake lens utilizes in-camera distortion correction. Without this correction, it gives a pronounced barrel distribution.

Compared with the Lumix 20mm f/1.7

It is natural to compare the lens with the other slim pancake from Panasonic: The Lumix G 20mm f/1.7. In the picture below, in which I am using a step down ring as a simple hood on the 20mm, it is very clear that the newer 14mm lens is significantly smaller. However, note that the 14mm lens has the slimmer rear lens cap mounted, which makes it even smaller.


The lens designs are rather different. The 20mm lens features 7 lens elements in 5 groups (2 aspherical), while the 14mm lens has 6 elements in 5 groups (3 aspherical).


Obviously, the 14mm lens has a wider field of view than the 20mm lens. The 14mm lens is a wide angle lens, while the 20mm lens is what people would normally call a "normal" lens. Normal lens have a focal length which correspond roughly to the diameter of the sensor. The Four Thirds sensor diagonal measures 21.6mm, so the 20mm lens is in fact a slightly wide normal lens.

Based on the field of view difference, which is quite significant, which lens would you want to buy? Experienced photographers will probably not ponder long about this. They are already well aware of the concepts "wide angle" and "normal lens", and know their preferences. What about the rest of us?

If you have used the kit zoom lens for some time, you could take a look at your favourite photos and see what focal length they were taken with. Did you typically use the wide end of the zoom lens? Or the longer end? The answer here might determine your focal length preference.

There is a philosophy which goes like this: You can always get closer to an object, but you cannot always get further away from it. So to be able to photograph what you want, choose the widest lens. In this case, this philosophy dictates that you choose the Lumix G 14mm f/2.5 lens over the Lumix G 20mm f/1.7 lens, since the former is wider.

However, it doesn't take much thinking to see that the premises are not always right. Let's say you want to photograph people. Then, you should not get closer to them than around 1 meter. Going closer will give you perspective distortion, which can make the photo unflattering.

Hence, if you intend to photograph a person, and want to have their face as the main part of the image, you will want to choose the longer lens. At a 1 meter distance, their face will be just a small spot in the frame with the 14mm wide angle lens. Even the 20mm lens is not long enough to be a portrait lens, but it is still the better choice. For a portrait headshot, you will generally want a focal length of around 40mm or higher. But the 20mm lens can be used to take an environmental portrait.

On the other hand, if you intend to photograph a group of people, you will want to choose the wide angle lens. You cannot always back up more, so the widest lens is best to cover a group of people.

Compared with the kit lens

The focal length 14mm is covered by the kit lens. So why get the 14mm pancake if you've already got the kit lens?

In addition to the kit lens, there are also other zoom lenses that include the 14mm focal length. In fact, there are eight zoom lenses available for the Micro Four Thirds format that cover 14mm: Two basic Olympus kit lens variants and two basic Panasonic kit lenses (14-45mm and 14-42mm). Then there are the two superzooms, and two wide angle zooms.

We've already discussed the size. The Lumix 14mm f/2.5 pancake lens is very, very small. This has a lot of advantages. You're more likely to bring the camera and lens if it is small and compact. Also, a small lens looks less obtrusive. It doesn't scare people the same way as a large lens does.

The 14mm pancake lens has also got a larger max aperture than the zoom lenses. The brightest zoom lenses are specified at f/3.5 at 14mm, which is about one stop slower than f/2.5. However, one stop difference isn't that significant. It means that you can use twice the shutter speed, roughly. While the Lumix 20mm f/1.7 pancake lens is a true low light lens, the 14mm pancake isn't overly fast. So if you buy it for the low light properties, you're bound to be unhappy.

Compared with the kit lenses, the pancake lens has a much simpler construction, with only six lens elements. This has the potential of making the image quality better, in terms of sharpness and contrast. However, how the image quality actually compares is unknown to me, since I haven't studied them head to head.

Conclusion

This is a very capable, fast focusing, sharp and compact lens. What's not to like?

22 comments:

  1. Is the 14mm different enough with th 20mm to make the buy ? I never saw a framing comparison between these two lenses...

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  2. Their diagonal angle of view are 57° (20mm), and 75° (14mm). This is a significant difference.

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  3. So 14mm is a wide angle... Thanks a lot !

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  4. 14 is a like a 28. (wide)
    20 is like a 40. (normal)

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  5. If M43 had a 12mm f1.7 i'd have fallen in love with the whole system again. This is like the second best sister, 14mm? f2.5? Maybe i'll hit it but it's not quite what I want/need.

    I need 3 fast (sub f1.8) primes 12mm (or wider), 20mm f1.7 (amazing) and a 35mm. They'd explode on the market and turn the scene around.

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    1. slr magic make a 12mm t1.6 hyperprime. manual though... http://www.eoshd.com/content/4435/slr-magic-noktor-12mm-f1-6-gh2

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  6. I know a lot of people have asked for a fast wide prime. However, I don't see the need for a 12mm f/1.7 myself.

    12mm can be used to make some shots that are impossible with the 14mm. Still, I think that 14mm is a more useful focal length for most usage. 12mm is more of a funky, novelty focal length, in my opinion.

    And the fast aperture? With the usability of high ISO nowadays, I don't see the need for f/1.7 on a wide angle lens. It makes good sense on the 20mm, but on a wide angle lens, I don't personally see this need.

    And from a narrow DoF perspective, I think that if you are after narrow DoF, you shouldn't use a wide angle lens at all.

    Olympus have god a 12mm prime lens on their roadmap, however, I would be surprised if it is very fast, given their m4/3 track record.

    I know that Canon and Nikon have got 24mm f/1.4 lenses. But these are for a limited number of professionals and dedicated amateurs who are ready to pay the premium price.

    As for the 35mm, I'm completely with you. I think that a 35mm f/2 lens could be made very compact for the m4/3 system. It would make good sense to me, and I would find it very useful. Preferably, it should have internal focussing (like the Lumix 14mm). Let's hope that someone from Olympus or Panasonic agree.

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  7. "12mm can be used to make some shots that are impossible with the 14mm. Still, I think that 14mm is a more useful focal length for most usage. 12mm is more of a funky, novelty focal length, in my opinion."

    I would have agreed with this a year ago. But after owning an LX5 for a couple of months, I find myself using the 24mm focal length a lot and the 35mm focal length a lot, and the 28 rarely. Which makes me think that for some folks, the 12 is less of a novelty than you think, or perhaps even than THEY think. Its all personal preference, but I thought I'd toss out that perspective.

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  8. The GF1 isn't exactly a high-ISO-friendly camera. I struggle with my 20mm pancake indoors at night. So the faster the lens, the better. Still, I love the idea of a portable wide-angle like this 14mm. Great for hikes and traveling.

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  9. Is there any prospect of a 7 or 8 mm wide prime that is rectilinear and not a fisheye? This would be an ideal companion to the 14-42 kit zoom and presumably cheaper than the 7-14 pana zoom.

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  10. According to Olympus's roadmap, they have a wide prime lens in the pipeline. Around 12mm. So it would not be as wide as the lens you want.

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  11. I just got this lens and it works great with my GH1. However I did find the photos aren't rotating automatically (both in camera and in PC). I know the 20mm pencake doesn't have the orientation sensor and I suspect the 14mm doesn't as well (since it's only half the weight). Can anyone help me confirm this? Thanks!

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  12. You are perfectly right: The pancake lenses do not have rotation sensors, and so, the images are not autorotated with Panasonic cameras.

    On Olympus cameras, they are automatically rotated, since the camera itself has the rotation sensor.

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  13. I hadn't any prior intention of buying the lens, but recently saw one advertised for what I considered to be a bargain price. Much has been made of the aperture and reduced sharpness around the edges, but in reality the 20mm f1.7 does not retain much of its sharpness around the sides when wide-open. I've found that it's possible to obtain very good results with the 14mm f2.5 in most lighting conditions. It is clearly not quite in the same league as the 20mm f1.7, but exceeded my own expectations and is very capable indeed.

    Thank you once again for another very accurate, unbiased and helpful review.

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  14. The Panasonic 14mm f/2.5 lens has grown a lot on me recently. I think it is a very good lens.

    It has a mixed reputation online. You will see some people saying it is not good optically. Personally, I think that considering the price and the size, it is a good lens in all aspects.

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  15. Hi. First of all, thanks for your very instructive blog. I just get a Panny 14mm for myself and I'm thinking on use a filter ring as a hood like you said, but I'd like to know if you believe it provides necessary incidental light protection. Thanks

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    1. Honestly, I think the real protection against incidental light is rather small. I prefer to use this filter ring, or step down ring, mostly to protect the front lens element. That is my main concern.

      Using a 46-37mm step down ring is probably a tad bit better in terms of protection against incidental light, but then you also need a new lens cap.

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  16. Thank you for the review! Helps a lot. Although i still have a slight dilemma - i'm planing on getting Lumix GX1, but i can't decide on the lens - should i choose more universal 14-42 kit zoom or this 14mm prime (i'd love to get the 20mm, but they seem to be out of stock everywhere). At least for a while, i want only one lens, and a small one (i recently sold all my DSLR gear, and i want to be free of extra equipment and the constant thinking which lens should i use now). So i'm trying to choose between these two. Kit zoom is small enough, but is it fast enough - both focusing speed and f speed. 14mm prime has fast focus and faster f, but maybe the wide angle is too wide for general shooting...

    I'll be using the camera mostly for travel and city shots. Can you help me chose? :)

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    1. I think you should go with the kit lens, as a start. The kit lens is a good lens. It focuses very fast as well. In fact, the Panasonic kit zoom lenses are among the very fastest in terms of focus.

      For travel and city shots, I'd say the kit zoom lens is a good choice. For low light use, you could add the Olympus 45mm f/1.8 or Lumix G 20mm f/1.7 later, depending on which field of view you prefer.

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  17. I have a Panasonic G10 model and I intend to buy this lens. However as the lens does not have OIS, so how does it perform with cameras without BIS (my camera does not have IS)?

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    1. As long as you keep the shutter speed faster than about 1/30s, you should be ok without image stabilization.

      It can be a bit difficult to record video without image stabilization. But since the focal length is pretty short on this lens, I don't think this would be a huge issue.

      So my conclusion is that you should not worry about it.

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