Sunday, 3 August 2014

Pancake zoom lenses compared

Panasonic announced the Lumix X PZ 14-42mm pancake zoom lens (my review) in 2011. Since this time, a collapsible pancake zoom has become a must have kit lens for most mirrorless systems. I have previously compared it with the Sony 16-50mm pancake zoom lens, and this time, I am comparing it with some similar lenses from Nikon.

Below, I have the four lenses laid out:


From left to right: Lumix G 12-32mm (my review), Lumix X PZ 14-42mm (my review), Nikkor 11-27.5mm, and Nikkor 10-30mm PD

On the Lumix lenses, I have used a 37mm filter ring as a simple protection against getting fingerprints on the front lens glass elements. To make them, I got cheap 37mm filters, and removed the glass.



Specifications


LensLumix G 12-32mm (my review)Lumix X PZ 14-42mm (my review)Nikkor 11-27.5mmNikkor 10-30mm PD
Aperture rangef/3.5-5.6f/3.5-5.6f/3.5-5.6f/3.5-5.6
Lens elements/groups8/79/88/69/7
Diameter56mm61mm58mm58mm
Length25mm27mm31mm28mm
Weight70g95g83g85g
Filter thread37mm37mm40.5mmNone
Hood suppliedNoNoNoNo
Optical image stabilizationYesYesNoYes
Manual focus on lens?NoneLever, 2 speedsNoneNone
Zoom operationManualPower, lever, 2 speedsManualPower, ring by wire


All the lenses share the same aperture range, f/3.5-5.6. However, it is important to understand that there are still different ways in which the maximum aperture changes through the focal length range. Here is a chart showing the equivalent focal length of the lenses (relating to the old 135 film format), and the respective maximum apertue for each lens:


There are many things to comment from this. We could argue that the Lumix lenses "cheat" in their specifications, as their maximum aperture more quickly goes to f/5.6. The difference between the Lumix X PZ 14-42mm and the Nikkor 10-30mm PD is about 1/2 stop at 60mm equivalent, which is a significant effect.

Also, we see that if you are interested in wide angle, the Lumix G 12-32mm may be the best choice, as it goes all the way down to 24mm (equivalent). Also, the Nikkor 11-27.5mm has the least interesting focal length range, starting at 30mm equivalent. Then again, it is designed to be a cheap and light lens, for use in the least expensive camera kits.

In use


Here is a video showing the startup sequence for the two motorized lenses:



As you see, the Lumix X PZ 14-42mm extends quicker than the Nikkor 10-30mm PD: Both are probably sufficiently fast, though.

The Lumix G 12-32mm is extended and collapsed by rotating the zoom ring:


This operation feels quite smooth, and the lens is rather rigid when extended. Some looseness of the extended front lens element can be felt in the extended position. This lens has an aluminium exterior, however, it is just a thin layer which is glued to a plastic mechanism and chassis. So while this lens has the most metal on the outside, it is still the lightest of the four lenses.

I think the ergonomy of the Lumix G 12-32mm is less than optimal. It has a nicely grooved zoom ring, but there is little to hold on to when mounting the lens. Why not have some ribbed surface at the base of the lens? That would have made the handling better.

Finally, the Nikkor 11-27.5mm operates like the Lumix 12-32mm lens. You twist the zoom ring to extend it, which also powers on the camera, a nice touch. This lens has a cheaper feel to it, with the zoom ring being less dampened. But it operates quite ok. The zoom ring is nicely rubberized, which I do like.

All of these lenses autofocus very quickly. For non-moving subjects, you are not going to find the AF speed problematic at all. For moving subjects, the PDAF technology employed by Nikon is generally superior, and the Nikon 1 system is the way to go for the best AF-C performace.

Image quality


To test the image quality, I have photographed the same scene with all the lenses, at different apertures. I used the Lumix GH4 and Nikon 1 V3 cameras, respectively. They were set to the base ISO, and I used a tripod.

Wide angle


Here are the pictures:

Lumix G 12-32mm @ 16mm f/3.9Lumix X PZ 14-42mm @ 15mm f/3.9
Nikkor 11-27.5mm @ 11mm f/3.5Nikkor 10-30mm PD @ 11.2mm f/3.8

To better compare the image quality, here are some 100% crops at various apertures. From the right centre area:


From the top, right corner area:


And from the top area:


From the long tele end


Here is a similar test for the tele range of the lenses.

Lumix G 12-32mm @ 32mm f/5.6Lumix X PZ 14-42mm @ 32mm f/5.6
Nikkor 11-27.5mm @ 24.1mm f/5.6Nikkor 10-30mm PD @ 23.1mm f/5.6

And 100% crops from the centre:


And from the lower left corner:


Analysis


I was a bit surprised when seeing these results. I had expected more differences, but the example images are in fact rather similar. From Panasonic, I notice that the Lumix G 12-32mm is clearly best in the tele end, while they are more closer at wide end. The Lumix X PZ 14-42mm does well in the wide end, but the 12-32mm lens is probably still slightly better even here.

From my previous experience, I generally find the Lumix G 12-32mm to perform the best out of the two Lumix lenses.

From Nikon, I think the Nikkor 11-27.5mm is slightly better. But the difference is small.

Comparing between the brands, it seems like the Nikon lenses generally do better than the Lumix lenses.

There is little Chromatic Aberration (CA) problems here. In high contrast areas, we probably see some small effects mainly from the Lumix lenses, but I wouldn't worry about them.

Geometric distortion


Most Micro Four Thirds lenses feature some in camera distortion correction. And these lenses, with the wide zoom range, are no exception. To examine the geometric distortion characteristics, I have photographed a square tiled wall, and then overlaid the out of camera JPEG (in black) with the uncorrected image (in red). I used the third party RAW converter software UFraw to assess the uncorrected image.

Lumix G 12-32mm f/3.5-5.6 at 12mm (-18%)Lumix X PZ 14-42mm at 14mm (-15%)
Nikkor 11-27.5mm at 11mm (-11%)Nikkor 10-30mm PD at 10mm (-9%)

The percentage in brackets is the relative distortion correction applied in The Gimp image processing software to get a rectilinear image. This is a way to compare the relative distortion between the lenses.

At 12mm and 14mm, you see that both the Lumix lenses still feature some barrel distortion, even after the in-camera image processing. This is not uncommon at short focus distances with wide angle lenses that feature internal focusing. The same can be seen also with the Lumix G 14mm f/2.5 at short focus distances.

The Nikon lenses, though, appear to avoid this problem. The Nikon lenses also have much less geometric distortion in the first place, and appear to rely more on optically correcting for the distortion.

A strange oddity with the Nikon system, though, is that the images are not corrected for geometric distortion in the viewfinder. So you are seeing the distorted images while composing the images, while the final image is going to be corrected. This is very strange, and surely makes it harder to get the right composition.

Here is an example, using the newest Nikon 1 V3 camera with the Nikkor 11-27.5mm at 11mm:

Seen through the viewfinder
The output image

Bokeh


Bokeh is the nature of the out of focus rendering. You may think that to look at bokeh for these lenses is a waste of time: With the small maximum aperture, most of the scene is in focus anyway, so why bother?

However, in the longer end of the zoom scale, you can still get the background out of focus by photographing close objects. Here are some example images:

Lumix G 12-32mm f/3.5-5.6 at 32mm f/5.6Lumix X PZ 14-42mm at 42mm f/5.6
Nikkor 11-27.5mm at 27.5mm f/5.6Nikkor 10-30mm PD at 30mm f/5.6

Here are 100% crops to better evaluate the bokeh:


In these examples, we see that the Lumix X PZ 14-42mm shows some ringing, which looks distracting.

In terms of bokeh, the Lumix G 12-32mm f/3.5-5.6 and Nikkor 10-30mm PD produce the best results.

Focus noise


There is one area where Panasonic surely has the upper hand: Focus noise. The Nikon lenses have a lot more noise during focus operation. It's not likely to be a major problem, but when comparing them head to head, it is clear that the Lumix lenses are much more silent.

Zooming during video


Two of the lenses are motorized, and there is the possibility to use the motor zoom during video recording. This works very well with the Lumix X PZ 14-42mm, which has a lever operated motor zoom. It has two speeds, making it easy to zoom smoothly while recording. The focus normally keeps up quite well.

Not so with the Nikkor 10-30mm PD, though. It also has a motorized zoom. But it is hard to zoom smoothly when rotating the zoom ring. The zoom appears to stop at some fairly widely distanced stops, making it quite jerky. The focus appears to keep up reasonably well while zooming for both lenses.

Here is a comparison which shows that the Lumix lens is by far superior. I used the Lumix GH4 and Nikon 1 V3 cameras.

Both videos were recorded at 60 FPS, 1080p.



In the video, the zooming starts at 0:05s and 0:20s.

Conclusion


While these lenses share a lot of characteristics, they are still very different.

First of all, if you are going to be using video a lot, then you should consider to go for Panasonic rather than Nikon. The Lumix lenses and cameras are just much better suited for video use.

If you would like to use the widest angles, then go for the Lumix G 12-32mm, which starts at 24mm equivalent, which can be fun and useful.

In terms of image quality, it appears to me that the Nikon lenses are consistently best.

As the Nikkor 11-27.5mm doesn't feature optical image stabilization, it may be sub optimal for use other outside during daytime. Also, video use can be a challenge without image stabilization.

As long as you don't plan to zoom during video recording, the Nikkor 10-30mm PD is probably one of the better lenses. It does have quite some operation noise, though, both during zooming and when focusing.

Most of the time, I use the Lumix G 12-32mm. Because it is very compact, has a good wide angle, and consistently gives very sharp images. Also, it has image stabilization, useful for video recording. It is a good, compact, all around lens.

Pros:
Very wide angle
Very light
Pros:
Two speed power zoom, good for video
Pros:
Consistent good image quality
Cheap
Pros:
Consistent good image quality
Automatic lens cap
Cons:
Poor ergonomy
Short in the tele end
Cons:
Not the best image quality
Cons:
No image stabilization
Noisy
Cons:
Jerky zoom operation
Noisy
No filter threads

6 comments:

  1. IMHO 12-32 has better performance over 14-42 on the wide end as well...

    ReplyDelete
    Replies
    1. Generally speaking, I find the 12-32mm lens to be the best out of the two Lumix lenses. So I agree with you. The 14-42mm lens is a fascinating lens, with the power zoom. But the image quality disappoints a bit.

      Delete
  2. hello fredrik, do you gonna test the new Tamron 14-150mm f3.5-5.8?
    thx!

    ReplyDelete
    Replies
    1. No, I don't think that lens is interesting enough. As I use Panasonic cameras, I wouldn't want to buy a long zoom lens without image stabilization. Besides, in my experience, the Lumix 14-140mm f/3.5-5.6 is so superior anyway, that I don't see the need for a new lens of this category.

      Delete
    2. ok perfect :) (i have the lumix 14/140 too)

      Delete