Sunday, 20 April 2014

Focus peaking with Lumix GM1

In 2013, focus peaking became a must have feature. The Lumix GH3 was released just in time to not get this feature. But all future camera releases now need to provide this feature.

Simply put, focus peaking is a form of assistance for manual focusing. It provides a highlight around the edges of objects that are in focus, so that you can quickly see where the focus is at. With the Lumix GM1, you can combine this with another commonly seen focus assistance, magnifying the image for more precise focus assessment.

Here is a video illustrating how focus peaking works with the Lumix GM1. I use the the Leica 25mm f/1.4 lens in the demo, as well as an old Nikon 24mm f/2 AIS on an adapter.



Here is a summary of some of the options related to focus peaking. The key to the feature is to set the "Focus Peaking" menu item to "ON":



Also, focus peaking only works during manual focus. So set the focus selector to MF. You do not get focus peaking during autofocus.

Use the "SET" menu item above to change the behavior of the feature: You can set the focus peaking highlight colour (I prefer yellow), and you can set the focus peaking detection level to "LOW" or "HIGH".

"HIGH" means that it will only give you the highlights when there are strong contrasts, i.e., the object is in focus for sure. "LOW" means that the camera will be more generous in making the highlights. Generally speaking, I prefer to use "HIGH" with M4/3 lenses, and "LOW" with adapted legacy lenses. That appears to work best for me.

Further, there is a fundamental choice of using the magnified view in addition to the focus peaking feature, or not. Personally, I prefer to just use the focus peaking feature, and not have the magnified view in addition. But you can set "MF Assist" to "ON" to enable the magnified view:



If you do, you can set the "MF Assist Display" to "FULL" or "PIP". "FULL" just enlarges the centre of the image across the full LCD screen image. "PIP" means "picture in picture", and gives you the whole view in the border, and the magnified view in the centre:



As you see, the focus peaking still works in this magnified PIP view.

Another good news is that the peaking works during video recording. This is good when using an adapted legacy lens for video recording. Or when using one of the large aperture manual focus lenses, like the Voigtlander Nokton 17.5mm f/0.95, which is liked for video use due to the possibility to get a very selective focus.

Thursday, 17 April 2014

Lumix G 12-32mm f/3.5-5.6 review: Small and brilliant!

The most remade lenses within Micro Four Thirds are the kit zoom lenses. Panasonic now have five kit zoom lenses, and so do Olympus, and this is not even counting the colour variations. While this has upset some fans - why don't they spend the effort designing high end lenses? - this makes perfect sense.

Most people who buy a Micro Four Thirds camera, get one with a kit lens supplied. Hence, the production volume of these lenses is big, and constantly improving them is a good idea. Also, to sell camera kits, they need to follow the trends. For example, the Lumix G 14-42mm f/3.5-5.6 did not match the current trends, with a matte plastic exterior. The market now wants shiny metal-like materials on consumer electronic products, and in comes the Lumix G 14-42mm f/3.5-5.6 II.

And the newest Lumix kit zoom lens is all about following trends. It is like the existing Lumix X PZ 14-42mm f/3.5-5.6 in the sense that it is a collapsible pancake lens. However, the new Lumix G 12-32mm f/3.5-5.6 also keeps in line with market trends by having a smooth aluminium body, with a simple shape. Both lenses are seen below:


Olympus also have a similar lens, the Olympus 14-42mm f/3.5-5.6 EZ, which I have not tested in this article. All three are specified in the table below:

LensLumix G 12-32mm f/3.5-5.6Lumix X PZ 14-42mm f/3.5-5.6Olympus 14-42mm f/3.5-5.6 EZ
Lens elements/groups8/79/88/7
Power Zoom?NoYesYes
Focus ring?NoLeverYes
Diameter56mm61mm61mm
Length25mm27mm23mm
Weight70g95g91g
Filter thread37mm37mm37mm
Hood suppliedNoNoNo

Physical


Both the Lumix pancake zooms are compact and collapsible, but beyond that, they are very different. The Lumix X PZ 14-42mm f/3.5-5.6 (my review) is a technological tour de force, with a two speed lever operated power zoom. It extends automatically and impressively quickly when powering on the camera.

The Lumix G 12-32mm f/3.5-5.6, on the other hand, is a much simpler lens from the looks: It has a basic cylindrical shape, with some grooves on the end of the zoom ring. And while the power zoom lens is a mixed materials lens, the newer lens has an outer body of nicely finished aluminium.



You extend the new lens by rotating the zoom ring counter clock wise:


Even if the new lens has a two section telescoping mechanism, it still feels very solid. Wiggling the front end section of either lens reveals that it is a little bit loose, but much less than you might expect. Even if the lenses are small, they feel very solid.

From the rear side, we see that they are quite similar. Notice that the new lens has a very large exit pupil. This is often associated with high quality lenses, although there is of course not an automatic connection:


As with all OIS lenses from Panasonic, these lenses rattle when not powered on. It is probably the OIS lens group which is decoupled when the lens is not powered by the camera. This is normal, and not a problem.

Handling the lenses, they are quite different. The Lumix X PZ 14-42mm lens has grooves in the base, to help you twist the lens in place when mounting it. Also, it has the embossed red symbol to indicate which way to mount it. This red half sphere is good to have, as you can feel which way to mount the lens without looking.

The new Lumix G 12-32mm lens has neither of these ergonomic features. It makes it look sleek, but functionally, it does lag behind. Personally, I would prefer function over looks in this case.

Hood


The lens does not come with a hood, and there is no hood you can buy specifically for this lens.

What you can do, though, is to get a 37-52mm step up ring and use it as a hood. The diameter of the step up ring matches that of the lens:


The step up ring is probably not going to keep a lot of stray light out, as would be the purpose of a hood. But it can help you to avoid getting fingerprints on the front lens element, and avoid accidentally banging the front lens element into objects. You also need a 46mm front lens cap to use on the front of the step up ring.

Using the step up ring as a hood is not going to cause any extra vignetting.

Aperture range


With the smaller size, one might expect that the new lens more quickly stops down the aperture as you zoom in. That is how Panasonic have been shrinking their lenses lately. In this respect, it turns out that the lenses are quite similar:


From the diagram, we see that both lenses reduce the aperture as you zoom in from wide to tele. The difference between them is very marginal, and hardly worth noting.

Focus


To test the autofocus speed, I mounted the lenses to the Lumix GM1 camera, and set a figure close to the minimum focus distance (20cm distance in the wide mode, and 30cm distance in the tele mode). Then I measured the delay from pressing the shutter until the camera snapped the picture. Here is the experiment:



And the results:

Lens/Focus delayLumix G 12-32mm f/3.5-5.6Lumix X PZ 14-42mm f/3.5-5.6
Wide0.32s0.34s
Tele0.46s0.36s

We see here that the new lens was slightly faster in the wide setting, while the old lens was faster in the tele setting. However, these results are very similar, and you are not likely to experience focus delay as any significant problem with these lenses.

As for the minimum focus distance, Panasonic states that it is 0.2m for both lenses. However, a more thorough measurement reveals that the minimum focus distance is longer in the tele setting:

Lens/Minimum focus distanceLumix G 12-32mm f/3.5-5.6Lumix X PZ 14-42mm f/3.5-5.6
Wide0.18m0.18m
Tele0.26m0.29m

Again, the lenses perform very similarly.

The new lens has no focus ring what so ever, so if you plan to focus manually, this may not be the lens for you. Focusing manually is possible through some camera menu, on some cameras. Generally, I don't see the need to focus this lens manually, so for me, this is a non-issue.

I find that manual focus is the most useful with long tele lenses, and with larger aperture lenses. And this lens is neither.

Image quality


I have previously compared the 12-32mm lens with some lenses at 12mm, and with some other lenses at 30mm. In these tests, I have generally found that the 12-32mm lens performs very well, considering the small size. It is not as good as Lumix X 12-35mm f/2.8, but then again, it is much less expensive, and a lot more compact.

Here are some head to head comparisons with the other pancake zoom lens, the Lumix X PZ 14-42mm:

Comparison @ 14mm


Here are the full images at 14mm. I had the sun behind me, making it more easy for the lenses to render the images:

Lumix G 12-32mm f/3.5-5.6Lumix X PZ 14-42mm f/3.5-5.6
14mm f/3.714mm f/3.5

For better comparison, here are some 100% crops from the centre of the image:


And from the top right corner:


It looks like the 12-32mm lens is better in the centre, but they are quite similar in the corner. Anyway, the performance is quite good.

Comparison @ 32mm


These example images were taken with the sun just outside the image frame, to the right. This is a quite challenging situation for any lens, as the strong contrast can cause a number of flare issues. It looks like the Lumix X PZ 14-42mm is adversely affected at f/5.6, but the Lumix G 12-32mm f/3.5-5.6 handles the strong light better, with little visible flaring:

Lumix G 12-32mm f/3.5-5.6Lumix X PZ 14-42mm f/3.5-5.6
32mm f/5.632mm f/5.6

For better comparison, here are some 100% crops from the centre of the image:


And from the top left corner:


In these examples, it is quite clear that the Lumix G 12-32mm f/3.5-5.6 gives the best image quality. Even wide open, the performance is very good.

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%)
Lumix G 12-32mm f/3.5-5.6 at 32mm (+3%)Lumix X PZ 14-42mm at 42mm (+5%)

The percentage in brackets is the relative distortion correction applied in The Gimp image processing software to get a rectilinear image. Hence, the distortion characteristics of the two lenses is very similar. The new lens has slightly more geometric distortion in the wide setting, though.

At 12mm and 14mm, you see that both 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.

Conclusion


The Lumix G 12-32mm f/3.5-5.6 is a very fine lens, which is true to Micro Four Thirds format. It performs well. You cannot expect a stellar optical performance, if you do, go for the Lumix X 12-35mm lens. But the performance is certainly very good for a small kit zoom lens.

This lens is recommended for those who want the smallest possible lens, which is still versatile, with a sensible zoom range. It pairs well with the Lumix GM1, for which is it the primary kit lens.

A final note is that the focal length range could be useful if you plan to use the 4K video mode of the upcoming Lumix GH4. In the 4K video mode, the GH4 crops the image, with an additional crop factor of about 1.2. Hence, the 12-32mm focal range corresponds to 14-38mm in 4K video mode, i.e., a normal kit zoom lens range.

Example image


Here, the sun is inside the frame, which is a very challenging situation for any lens to render. The focus distance is very close, around the minimum focus distance. Exposure parameters: 14mm, f/7.1, 1/500s, ISO 200. The bokeh is quite nice. There is some slight ringing in the tree in the top right part of the frame, otherwise, no issues:


The example image shows that the lens handles flare very well. This is important for a lens with a wide field of view.

Another example, at ISO 100, 1/100s, 12mm, f/5.6:


Here are some 100% crops from the image:


And an example at 32mm, f/7.1, ISO 200, 1/160s:


Here are 100% crops:



We see that the sharpness is very fine.

Saturday, 12 April 2014

Third party battery for the Lumix GM1

A spare battery for a digital camera is a good thing to have. If the battery runs out, the only way to charge it would be to remove it from the camera and place it in the charger, provided you are somewhere with a power outlet. This means not being able to shoot for an hour, at least.

If you carry a spare, charged battery with you, you can just exchange the battery in a matter of seconds, and be ready to shoot again. However, original batteries often cost a lot. The GH3 battery can easily cost US$80 new.

With the GH2, the third party batteries did not let the camera see how much power was left, hence, you would not get any "power bars" in the camera display. And even worse: When the battery eventually run out of juice, the camera would just die instantly, and the images in the buffer, not yet written to the memory card, would be lost. If you were recording video while the battery died, you would lose the video footage.

With the Lumix GM1, though, third party batteries are available cheaply, and they let the camera see how much juice is left. So, from the point of not losing data when running out of juice, they are safe to use. Just like when using original batteries, the camera will warn you that the battery power is low. And, eventually, the camera will stop video recording and write the data to the memory card before shutting down.


The battery I tested is marked with "FOR PANASONIC DMW-BLH7E", indicating that it replaces the original battery called Panasonic DMW-BLH7E. Just like the original battery, it is marked with 860mAh, i.e., the same power reserve.

Here it is next to the original battery, original to the right:


And from the side:


The third party battery is a bit lighter. It appears that it is covered by a plastic film, rather than the solid plastic body of the original battery. So it is probably not as rigid.

I have not formally tested if they carry the same amount of power reserve, but so far, the third party battery appears to be as capable. It charges in the same charger as the original battery.

The third party battery is a good alternative to the original version. It appears to perform as well, and is good to have in the camera bag as a replacement power, for the times when you need it. At the low cost, I would recommend getting a second battery for spare power.

Tuesday, 8 April 2014

JVC joins MFT, and launches large sensor 4K video

The big news this week is that JVC (JVC Kenwood) is joining the Micro Four Thirds format. So far, they have announced two 4K video cameras. The GY-LSX2 is a camcorder style video camera, while the GW-SPLS1 is a modular camera unit:

JVC GY-LSX2JVC GW-SPLS1
(Image from dpreview.com)(Image from dpreview.com)

These cameras have a Micro Four Thirds mount, of the "active" type. This means that you can use autofocus, you can set the aperture from the camera, and operate OIS.

Larger sensor!


However, in one way, they are very different from Micro Four Thirds cameras: The sensor is larger. The cameras will use the Altasens AL41410C sensor. Just like the Lumix GH4, it can record 4K video in 3840x2160 (Quad HD) and 4096x2160 (Cinema 4K).


It is different, though, in the sense that the 4K area of the sensor is 21mm x 11mm, with an image circle of 23.7mm. This is larger than the 21.6mm image circle of the Four Thirds sensor.

Do you need new lenses?


So does this mean that you need to buy new lenses to use this camera? Probably not. Many Micro Four Thirds lenses already cover a larger area than the 17.3mm x 13mm Four Thirds sensor.

Obvious examples are the Sigma lenses (19mm f/2.8, 30mm f/2.8, 60mm f/2.8). Since these lenses have optical designs for covering the APS-C sensor format, they readily cover the sensor area of the new JVC 4K video cameras as well.

But that is not all. Using an adapter, I mounted some M4/3 lenses on an APS-C sized sensor camera. I had a hard time finding lenses that did not cover almost the entire APS-C sensor size. Here are some examples (click to enlarge):

Lumix G 14-42mm @ 18mmOlympus 45mm f/1.8
Lumix G 14mm f/2.5Lumix G 20mm f/1.7

Note that the image is a not centred perfectly in these examples. This is due to the crudeness of the adapter. This also explains why the focus is bad.

Also, you'll see that some of the images have a bit of barrel distortion. This is because the geometric distortion correction is not done. I'm sure the JVC cameras will do this distortion correction inside the camera, eliminating this problem.

Apart from these oddities, you'll note that in most cases, the image circle is sufficient to fill out the Super 35 sensor of the new JVC cameras. So the good news is: Most of your lenses are probably going to work quite well on the JVC camera.

On the other hand, even if the image circle does cover the Super 35 sensor area, it could be that the quality of the image in the corners may be unsatisfactory. But I am sure that a lot of tests will pop up, saying which lenses you can trust, and which you cannot trust.

Conclusion


JVC joining Micro Four Thirds is very good news, and interesting. They are going to bring a lot of pro videographers to the Micro Four Thirds system. And another good news is: Your lenses are most likely going to be useful for the new system, even if the sensor requires an image circle larger than Four Thirds.

Another thing to note is that using a bigger sensor means that your lenses will become wider, effectively. Using the image circle diameter as the scaling parameter, there is a crop factor of 1.8. This means that a 14mm lens will become equivalent to 26mm for a traditional film format!

Sunday, 6 April 2014

Life after the GH4

The Lumix GH4 was recently announced, with a ground breaking feature for a consumer mirrorless camera: 4K video. Now that this milestone has been reached, what can we expect from future cameras? After all, the development still continues.

Image quality


The main news with the Lumix GH4 is of course the video features. However, the GH4 also adds a lot of features that make it a viable upgrade for those who are mostly into photography, e.g., better flash sync speed, faster burst rate, also while doing continuous autofocus.

Over the recent years, we have seen significant improvements to the image quality coming from digital cameras. We get a better dynamic range, and less noise, especially at higher ISO. I expect this development to continue, of course.

At this time, it looks like the Lumix GH4 is roughly equivalent to the GH3 in terms of image quality. Early comparisons show that the GH4 produces sharper images at high ISO, however, it appears to be mostly due to more aggressive sharpening. This is also the case with the GM1, which appears to apply more sharpening to the out of camera JPEG images.

While the current image quality performance is very good, future generations will still improve this.

Dynamic range in Video


When improving the video output from previous generation M4/3 cameras, there are essentially two approaches: Increase the resolution, as the GH4 does by adding 4K video, or increase the dynamic range of the 1080p video stream.


Increasing the dynamic range requires using higher bitrate video and other codecs that support more bits per pixel. An example video camera that does just this is the Blackmagic Pocket Cinema Camera. It accepts Micro Four Thirds lenses, however adding an additional crop factor. With the crop factor of 2.88, it makes a 14mm lens into a 40mm equivalent short normal lens.

The camera supports ProRes 422 high dynamic video output, and also lossless CinemaDNG coded. While this sounds all well, the downside is that using all this dynamic range requires professional processing of the video output, called "grading". Without competent grading of the video stream, the video is just going to look grey and boring.

So it is probably not surprising that Panasonic chose to increase the resolution over increasing the dynamic range when creating the Lumix GH4. While getting the real world benefits of a higher dynamic range requires a lot of competence, everybody understands that higher resolution is better. Selling 4K is easier.

Still, future Micro Four Thirds cameras may very well go down the high dynamic range path as well, adding ProRes 422 or CinemaDNG as optional output file formats.

4K video without a crop factor


A downside of the Lumix GH4 4K implementation is that not the whole sensor area is used:


So in 4K mode, a 14mm lens behaves like an 18mm lens (36mm equivalent) in terms of field of view. For people using the GH4 4K video feature, a wide zoom lens therefore becomes valuable, e.g., the brilliant Lumix X 12-35mm f/2.8.

The reason for this implementation is simple: Using the whole sensor for 4K video would require downscaling from 4608x2592 (16:9 sensor area) to 3840x2160 (4K) for each frame. High quality scaling of images is very computer intensive, and cannot be done with current technology. Here, Panasonic have an improvement potential.

As a side note, Sony is releasing a new version of their Sony A7 capable of 4K video. Somewhat strangely, this Sony A7S has a sensor with only 12MP. However, the reason for this is very easy to understand in the light of this article: It is to be able to produce 4K video without cropping, and without rescaling the sensor output. They could have sampled the 4K video stream from a larger sensor too, but that would typically lead to line skipping artefacts.

Higher video framerate


So far, no Micro Four Thirds cameras support higher video framerates than 60FPS.

Many competitors do better. E.g., Nikon 1 cameras support video framerates up to 1200, albeit at a reduced resolution.

Perhaps some will say that this is largely a gimmick, but I think it would have been a fun gimmick to have.

Global shutter


Traditionally, cameras have required a mechanical shutter. This curtain shutter starts and stops the exposure. However, a mechanical curtain shutter is infeasible for video use. Hence, the exposure is started and stopped electronically.

This will be the future of cameras: An electronic shutter which is silent and doesn't wear out. So far, some Panasonic Micro Four Thirds cameras include an electronic shutter, however, it is not very useful yet. The GH3 electronic shutter has a 1/10s readout speed, which is very slow and has a lot of side effects. The GM1, on the other hand, has a somewhat faster electronic shutter at 1/25s, which is better but still not perfect.

Other manufacturers have come further in this respect. For example, the Nikon 1 cameras have an electronic shutter readout of 1/80s, and some models have gotten rid of the mechanical shutter completely. Using this electronic shutter feature, the cameras, can take 60 full resolution images per second, which is very useful for sports applications.

An electronic shutter capable of instant readout is called a "global shutter". This is the aim for the development, but we will probably not get there during the near future.

Autofocus


Current Micro Four Thirds cameras have a very fast autofocus for static still image use. This hardly needs any improvement.

On the other hand, continuous autofocus of moving subjects is still not very impressive. The same goes for autofocus during video recording.

Other manufacturers try to address this by employing on-sensor PDAF detectors, e.g., Nikon 1 and Canon 70D.

Panasonic have said in interviews that they don't believe in on-sensor PDAF. They rather want to improve the autofocus by improving the image processing technology. This requires improvements in both the processing algorithms, and in the processing speed.


Conclusion


While the Lumix GH4 is certainly an impressive camera, there are many ways in which the cameras can continue to improve. Can you think of other improvement areas?

Tuesday, 1 April 2014

New 20mm f/1.7 lens is less noisy!

The Lumix G 20mm f/1.7 pancake is a classic Micro Four Thirds lens. Being the first Panasonic prime lens, it is widely considered to be very well performing. But it has some shortcomings: Due to the old fashioned focus design, where the whole lens assembly moves back and forth during focusing, the autofocus is rather slow. Also, the large focus assembly makes it very noisy when focusing.

Also, when using the lens on some cameras at high ISO, many users report annoying horizontal stripes. Some believe this is due to a spiral coil spring inside the lens, which is one of the ways in which it is different from other lenses that don't exhibit this aberration.

In 2013, Panasonic updated the lens. It is well known that the new lens is largely a cosmetic redesign: The optical layout is the same, and the focus method is the same. But is the new lens better? The new lens is available in black and silver, and you can see the silver version to the right below:


Old (left) and new (right) versions of the Lumix G 20mm f/1.7

LensLumix G 20mm f/1.7Lumix G 20mm f/1.7 II
Lens elements/groups7/57/5
Aperture diaphragm blades77
Minimum focus0.20m0.20m
Diameter63mm63mm
Length26mm26mm
Filter thread46mm46mm
Weight100g87g
Hood includedNoNo
Optical image stabilisationNoNo

As the noise and autofocus speed is the achilles heel of the Lumix G 20mm f/1.7, I have tested them head to head in these aspects. I used an Iphone to test the noise, and tested the focus speed on a Lumix GM1. This was done by checking the focus delay when changing the focus from infinity down to 0.20m, the closest focus distance. Here is a video summary of the test:



And a summary of the findings:

LensLumix G 20mm f/1.7Lumix G 20mm f/1.7 II
Focus delay0.80s0.84s
Focus noise57dB50dB
Aperture change noise70dB72dB

Conclusion


The focus speed is very similar between the lenses. The difference I found is most likely not significant, it could be just due to random differences in the testing parameters. So my conclusion is: The lenses have exactly the same focus motor/assembly.

The focus noise, though, shows a significant difference. Both lenses are still noisy, by modern standards, but the new one less so than the old lens. Perhaps this is due to the use of different materials in some components. Whatever the cause, this is good news: Focus noise is less likely to be a problem with the new lens.

The aperture change noise shows some difference in my measuring, but I would say it's hardly significant. This noise is on a quite normal level for Micro Four Thirds prime lenses. Zoom lenses tend to be less noisy, as they have smaller apertures. I've found the most noisy aperture on the Leica 25mm f/1.4, not surprising since it has a very large aperture.

Focus assembly


A closeup of the two lenses shows that they have the same outwards appearance in the focus assembly:


In both lenses, you'll see a small gap between the outer chassis, and the lens assembly. The inner tube moves in and out when changing the focus. Hence, you cannot mount a step up ring on the lens: It can cause the focus assembly to lock up. It has happened with me, so take care.

You can, however, mount a 46mm to 37mm step down ring as hood. This gives some basic protection of the front lens element, while keeping the overall package compact. If you go down this route, you also need a 37mm front lens cap.:



Friday, 28 March 2014

Comparison @ 30mm

The launch of the Lumix GM1 compact M4/3 camera also brought the collapsible wide zoom lens, the Lumix G 12-32mm f/3.5-5.6 Mega O.I.S. It is seen below to the left in the extended position, together with the Sigma 30mm f/2.8 DN and the Lumix X 12-35mm f/2.8:


The Lumix G 12-32mm f/3.5-5.6 is designed with a form factor to fit the new Lumix GM1 compact camera. It has a clean, smooth look, and is one of the few lenses which is small enough to go flush with the very low GM1 camera body.

The Sigma 30mm f/2.8 DN is a slightly long normal lens. It's not very impressive in terms of the maximum aperture, but it has a consistently very good image quality, and a noiseless, quick autofocus.

On the 30mm lens, I have used a 46mm to 28mm step down ring as a hood. It does a good job of keeping the front lens elements safe from accidents, in my opinion, while also keeping out some stray light. If you want to use it, you also need a 28mm front lens cap.

The Lumix X 12-35mm f/2.8 is Panasonic's answer to the classic standard pro zoom lens. It is very compact for a lens of this class, and performs excellent. It is probably the best lens I have ever used.

LensLumix G 12-32mm f/3.5-5.6Sigma 30mm f/2.8 DNLumix X 12-35mm f/2.8
Lens elements/groups8/77/514/9
Aperture diaphragm blades777
Minimum focus0.2m0.30m0.25m
Diameter56mm61mm68mm
Length24mm (not extended)39mm74mm
Filter thread37mm46mm58mm
Weight70g135g305g
Hood includedNoYesYes, well designed
Optical image stabilisationYesNoYes
Price$350$200$840

The new 12-32mm lens is remarkably compact. The addition of a compact, light and affordable wide angle zoom lens is good news. It is what I have been waiting for a long time. But how does it fare, quality wise, in the longer end, at 30mm? Here is a comparison at 30mm with the three lenses.

I took the images using the Lumix GM1 on a tripod, at ISO 200. The focus was done with autofocus:


Sigma 30mm f/2.8 DN
Lumix X 12-35mm f/2.8 @ 30mm f/2.8

To better compare the images, I have compiled 100% crops from the centre of the images at various apertures:


We see that all the lenses do quite well here. Both the f/2.8 lenses are a bit duller wide open, and sharpen up slightly more at f/4. But the difference is very small. Both lenses are very good wide open in the centre.

The Lumix G 12-32mm also does well here. The sharpness is perfectly fine wide open in the centre.

And here are 100% crops from the top right hand of the images:


Lenses typically do worse in the corners. The crops from the top right corner shows that all these lenses are very good. The Lumix X 12-35mm f/2.8 is performing superbly wide open, for a f/2.8 lens. The Sigma 30mm is a tad bit duller, but it is still very usable.

Conclusion


Considering that the Lumix G 12-32mm f/3.5-5.6 is a compact kit zoom lens, I think it does very well here. It is certainly quite sharp wide open, even in the corner.

All these three lenses are very good, and which one you choose would depend on your needs. If you want a small and flexible lens, go for the Lumix G 12-32mm f/3.5-5.6. If you want the best lens, at a higher cost, get the Lumix X 12-35mm f/2.8.

The Sigma 30mm f/2.8 DN is a very good lens at a reasonable price.

Further reading


In this article, I have compared the two zoom lenses at 12mm. The conclusion is mostly the same: The Lumix X 12-35mm f/2.8 has a stellar performance, while the Lumix G 12-32mm f/3.5-5.6 is very good for a small kit zoom lens.

If you are interested in the bokeh performance, I have compared the two f/2.8 lenses here. I find that the Sigma 30mm f/2.8 DN has the most smooth bokeh, but the Lumix X 12-35mm f/2.8 is certainly very adequate.


Sunday, 23 March 2014

Using Silkypix on Linux

For years, I have been a fan of Linux. However, I admit to have missed some software from time to time. One example is RAW converters.

Sure, there are many RAW converters available for Linux, like UFRaw and Raw Therapy. However, they tend to not support the newest camera models. And also, while the programs are quite powerful, they require a lot of competence and time to use.

But there is good news: Panasonic's own RAW converter Silkypix can be installed on Linux, using the Windows emulator Wine. Here's how I did it.

I'm using the Kubuntu 13.10 release, but this should work on most recent Linux installations. First, make sure you have access to the most recent Wine installations by adding the relevant repository.  You can do it by issuing this command in a terminal window:


$ sudo add-apt-repository ppa:ubuntu-wine/ppa

Second, install Wine like this:


$ sudo apt-get install wine

Now, having installed Wine, we need to download Silkypix. I got it from http://www.isl.co.jp/SILKYPIX/english/p/support/download/

The version I downloaded was 4.1.1 for Windows, but newer versions may appear later on this download page.

To install Silkypix using Wine, I issued this command in the terminal window


$ wine SILKYPIX4SE4111.exe

This opens up some installation windows, which I am sure you have clicked through a number of times before:



When the installation process finished, an icon appeared on the desktop:



Doubleclicking this icon starts up Silkypix via the Wine Windows Emulator. And it works just like the Windows version.

A comment on the installation process is that I found that my old Wine configuration was causing some problems. I have used Wine on this account for nearly two decades (!), so to overcome these problems, I simply deleted the whole configuration catalogue:


$ rm -r ~/.wine

But only do this if you absolutely need it.

Conclusion


While Linux RAW converter programs are perfectly fine, they some times lack the support for the most recent cameras. And getting good images takes less effort using Silkypix than programs like UFRaw or Raw Therapy, in my opinion.

So for me, being able to use Silkypix in Linux with the Wine emulator was a big relief. All the programs mentioned here are free, in the gratis meaning of the word, to use.