"Dances with fire", example Lumix 14mm video

This video was recorded using the Panasonic GH2 and the Lumix G 14mm f/2.5 pancake lens.



I left everything on auto, and just pushed the red video button. This gives me a 720p AVCHD video stream. Since I dislike the highest resolution 1080i mode, due to the interlace, I tend to use 720p progressive mode. I have the European version of the camera, so the frame rate is 50fps.

Sadly, the camera does not seem to record the image parameters when making video captures. So I don't know for sure what aperture, shutter speed and ISO was used. But I would guess the camera selected the largest aperture, f/2.5. And the shutter speed was probably as slow as possible for a 50 fps video, so around 1/60 second. The ISO was probably pushed up quite a lot, I would guess around 1600-3200.

Focus

I had autofocus selected (AFS). It would probably have been a good idea here to prefocus, and then select manual focus (MF) during the video capture. That is to avoid having the focus hunt during the video capture. You can see that the camera jogs the focus back and forth now and then, to verify that the image is in focus. But since the Lumix G 14mm lens focuses very fast, this is barely noticeable, even in this low light situation.

With the Lumix G 20mm f/1.7 pancake, the focus is slower, and it can wander off for some seconds when recording a video. For the 20mm lens, it is best to have some control over the focus during videos.

White Balance

The white balance was also left on auto (AWB). This gives a slightly yellow tint to the images. Perhaps I could have tweaked the white balance better. But this is hard to do when you don't have time to plan the video capture in advance. On the other hand, the yellow colours are actually true to the actual lightning conditions.

Flare

Notice that there is some flare in the video. You can see that the flames generate greenish ghosting symmetrically opposite along the optical axis. This is quite common when you have strong light sources inside the image frame.

This illustration shows the relationship between the actual light source and the flare:

A lens hood would not have helped, since the hood is only designed to keep out light which comes from outside the image frame.

Generally, flare is more of a problem the more lens elements the lens is composed out of. So generally, you would find flare to be a bigger problem for a zoom lens, which can easily have more than ten individual lens elements, than for a prime lens. The Lumix G 14mm f/2.5 pancake lens only has six lens elements. However, the optical formula and the quality of the lens elements is also important for the flare characteristics.

Using a protective lens filter on the front of the lens can give you more lens problems, especially for low quality lens filters.

Audio

I used the onboard microphone, and left the levels on auto. It sounds like the sound is clipped some times. But I would guess this is actually due to the sound system being run to loud, and not due to the microphone.

Using an external microphone probably has the potential to give better sound in the video recording. But it makes the setup look much more professional, which might scare some people, and hence negatively affect the video. Using the GH2 with the 14mm pancake lens gives a very compact and non-obtrusive package, which is handy for recording everyday life.

Lumix 14mm as a video lens.

The very fast autofocus and the inaudible focus action make the Lumix G 14mm f/2.5 an ideal video lens.

It has a generously wide field of view, which is useful when video recording a group of people. The wide field of view also makes it easy to handhold the camera without the hand shake affecting the video stream too much.

The small size and unobtrusive looks also makes it easy to get close to people without scaring them, which is a big plus if you intend to video record people.

On the other hand, a zoom also comes handy for video use. For some more flexibility, I would recommend the Lumix G 14-42mm f/3.5-5.6 basic kit zoom. It is light, very fast focusing, and pretty good quality.

A tale of a broken Lumix kit lens

Contrary to much of the online opinion, I think that the basic kit lens from Panasonic, the Lumix G 14-42mm f/3.5-5.6, is rather good. Considering the price, the size and the weight, I think it gives a good performance. The autofocus is fast, the sharpness is generally good.

However, when evaluating the bokeh characteristics of the lens, I noticed that the out of focus highlights were non-round. This is found for some lenses, for example the Lumix Leica 45mm f/2.8 1:1 macro lens has elliptical out of focus highlight rendering outside of the centre of the frame. But I found that the Lumix G 14-42mm lens had more like potato shaped highlights.

A closer examination revealed that the aperture diaphragm was indeed misaligned, giving non-round out of focus highlights for all stopped down aperture sizes. If found this to be so bad, that I took the lens back to the shop where I bought it in the first place.

The store keeper has some problem verifying that his off the shelf lens did not exhibit the same non-round aperture. I helped him by taking a photo with the lens mounted to the Panasonic GF2 camera at f/9, 2 seconds, and removed the lens during the exposure. Looking towards the light through the lens showed that his copy had a round aperture.

So he accepted my lens as defective, and sent it for repair.

After one month, I started enquiring about the lens. I always got the same answer: "The lens is just around the corner, should be in our store the beginning of the next week."

It was not until after three months that the lens finally did arrive in the store. When I went to pick it up, I was told that they simply replaced the lens with a new one. Why let me wait for three months when they would just give me a new copy?

Coming home, I once again checked if the aperture was rounded. See for yourself, this image was taken with the Lumix Leica 45mm f/2.8 1:1 macro lens:

In fact, my new lens exhibits exactly the same problem as the one I returned in the first place. I did check that the new lens has a different serial number, so it is not the same lens that I returned.

Letting me wait three months for a new lens is bad. But giving me a new lens which has the same problem as the one I returned is simply appalling.

Epilogue

I took the lens back to the retailer again. This time, they offered to change my lens directly from their stock. We tested two lenses, and neither had completely round apertures. One was as bad as my own lens, and the other was pretty rounded. So I took the best one.

I don't expect perfectness from a lens this cheap. So I am happy with the near round aperture opening.

Bokeh, part 1

The term "bokeh" is commonly found when reading about photography. I would like to discuss bokeh in this series of articles. I don't intend to cover all aspects of bokeh, and I realize that not all would agree with my opinions. So you should view this as my personal opinions, and not as facts.

When using the word "bokeh", one normally means the nature of out-of-focus rendering. How the lens renders objects that are out of focus, the bokeh, depends on a number of factors, for example, the lens itself, the objects photographed, and settings like the focus distance and the aperture.

It does not make sense to say that "a lens has bokeh", or that "there is bokeh in a photograph". Rather, the term can be used to describe the out of focus rendering, e.g., "this lens gives me good bokeh", or "in this photo, the bokeh is distracting".

GH2, built-in flash for macro use

Lightning is critical for macro photography. To illustrate this, I will present a scene I tried to photograph. I used the Panasonic Leica Lumix DG Macro-Elmarit 45mm f/2.8 1:1 Macro lens. To make sure I used the maximum magnification, I selected manual focus (MF), and moved the focus ring until I reached the closest focus distance. Then I placed the camera so that the subject came in focus. This way, I was sure that I used 1:1 macro, which means that the subject is the same size as the sensor area, 17.3mm x 13.0mm.

As a test subject, I originally intended to use a bee. However, I found that chasing a bee around while it was visiting flowers, was much too difficult. Therefore, I found a bee that had been killed by a spider's web. With the bee being suspended, it was much easier to photograph in a controlled fashion.

First, let's consider what aperture to use. The PL45 lens has a maximum aperture of f/2.8, which has been criticized as being too small. Many would have preferred it to be f/2, to make the lens more useful for portraits. In this case, I want to have some depth of field, so I try to set it to f/5.6, a point at which many Micro Four Thirds lenses reach their optimum performance.

Here is the image at f/5.6, 1/60s, ISO 3200:

As you can see, the image is in fact not very good. One wing is in focus, the other is not. The rear part of the bee is in focus, but not the front. We can easily conclude that the depth of focus is too thin: Only parts of the insect is in focus.

To get a better depth of field, let's set the aperture to f/13. Some may worry that f/13 is too small, and will give some dullness due to diffraction. That is true, but as long as you don't make a big magnification of the print, that should not be a problem. For web use, f/13 is no problem at all, and you could even try to use f/16 if needed. I have studied the diffraction effects here.

I took ten images at f/13, 1/15s, ISO 3200, and this one is the most successful:

There are some problems here. First, you can see that the image is not framed very well. I was handholding the camera, which makes framing hard. Also, while the image has much better depth of focus than the previous, it now has some motion blur effects. The shutter speed, 1/15s, is much too slow to handhold the camera, even with Optical Image Stabilization (OIS). Finally, the high ISO at 3200 makes the image a bit noisy.

There is an easy way to solve all these problems: Just use the built-in flash. It turns out that the small built-in flash does cover the entire frame when using the PL45 lens at the closest focus range. The illustration below explains why.

In the illustration, a LEGO figure is placed at the minimum focus distance of the lens. At 1:1 magnification, the distance from the front lens element is 7cm. The built-in flash covers the focal length of 14mm, which corresponds to 75° diagonal field of view.

The resulting image is this:

As you can see, the entire image frame is illuminated by the built-in flash, even at maximum magnification.

A note about the lens hood: I don't like the supplied hood. It is much too wide, and does not do a good job at keeping out stray light. So I made my own hood, composed out of three elements: A 46mm stand off ring (glassless filter), a 46mm-37mm step down ring, and finally a 37mm-28mm step down ring. This gives the ultimate protection against stray light (in my opinion), and also good protection against objects touching the front lens element accidentally.

If you use the original hood, the light from the flash will be blocked by the hood, and you cannot use the built-in flash with macro images.

Back to our bee example. Here is the same image taken with the on-board flash, at f/13, 1/60s, ISO 160:

Using the flash allows for base ISO (160), and there is no problem with camera shake. The flash light is very quick, and freezes the image instantly. We clearly see that this image is much more sharp.

On the other hand, this method is not perfect for macro images: We see that the background has become very dark. This is because the flash light spreads out, and becomes less powerful for the background at a larger distance. Also, the flash light coming from a single light source does give a "flatness" to the image, which is not optimal. The nature of the image changes completely when using the flash.

Using the built-in flash for macro is a quick and easy way to get usable macro images.

Concert video with GH2 + 20mm pancake

Here is a video recording of a concert with the Frank Znort Quartet using the Panasonic GH2 and the Lumix G 20mm f/1.7 pancake lens.

I prefocused and then selected manual focus (MF) before starting the video recording. This was done to avoid focus hunting during the video. The 20mm lens is one of the slowest focusing Micro Four Thirds lenses, and it can sometimes jog a bit back and forth during video recording, which can lead to some seconds of out of focus footage. So it is usually better to set the focus you need and the turn AF off while video recording.

The video mode is the Cinema 24P, with 1080 lines of resolution. I used ISO 1250, f/1.8, and 1/60 shutter speed during the video. The camera was handheld.



You can also see the video in HD by clicking here and going to the YouTube page.

The band is playing "Pills", a cover of a Bo Diddly song, later made popular by The New York Dolls.

Focus noise compared

Focus noise can be distracting. If you are in a silent environment, noise from the autofocus will distract the people you try to photograph, and will potentially make you look stupid.

Most Micro Four Thirds lenses have internal focusing, meaning that some smaller lens elements inside the lens move to achieve focus. This is generally fast and silent.

To illustrate the difference in focus noise, I made some measurements using an Iphone. Now, I don't believe the Iphone is very well calibrated. So the absolute noise measurements are probably not too accurate. But the relative noise levels can be studied this way.

To measure the noise, I put various lenses on the Panasonic GH2, and put the camera in continuous autofocus mode, AFC. In this mode, half pressing the shutter will make the focus job back and forth continually. I pressed the shutter 3-5 times for about one second each time, to capture the noise level.

Here is a video showing the study:



The results:

Lens	Measurements	Average
Lumix G 8mm fisheye	50 46 52 51	50 dB
Lumix G 14mm	49 51 47 48	49 dB
Lumix G 20mm	61 60 58 59	60 dB
Leica Lumix DG 45mm macro	51 52 50 52	52 dB
Lumix G HD 14-140	55 62 65 62 61 60	61 dB
Lumix G 45-200	50 53 56 54	54 dB
Olympus ZD 4/3 50mm f/2	76 79 81	79 dB

Conclusions

The outcomes are mostly as expected. The Lumix G 20mm f/1.7 pancake lens is the odd man out in this test. Since it is the only Micro Four Thirds lens that features a traditional focus mechanism, and not internal focus, it is also the most slowly focusing and noisy. The lack of internal focus means that the whole focus assembly moves during focus. You can see this in the video.

Perhaps the only surprise in the test is the relatively loud focusing noise from the Lumix G HD 14-140 superzoom lens. This lens is marketed as a video optimized lens, and features fast and silent operation. I would speculate that the noise picked up is not only from the focusing, but also from the OIS unit, which is powered when half pressing the shutter. Also, since this is the largest lens, the sound comes from a source closer to the mobile phone picking up the noise. Hence, the sound reading should be expected to be more audible. So I would take the measurements from the 14-140mm lens with a grain of salt.

The Olympus ZD Four Thirds 50mm f/2 macro lens is not a contrast detection autofocus (CDAF) optimized lens, and therefore it is rather slow to focus. It also generates a lot of noise, since it moves large lens groups back and forth. This lens is mostly useful for studio work on Micro Four Thirds, I'd say, due to the very slow autofocus.

The final word is that most Micro Four Thirds lenses, except the 20mm pancake, focus very fast and virtually noiseless.

Another aspect is the noise from the aperture change. I have not measured this, but my experience is that this is rather noisy with all lenses, except the Lumix G HD 14-140 superzoom lens. The 14-140mm lens has an almost inaudible change of aperture.

I would have liked to test the Lumix G 14-42mm f/3.5-5.6 kit lens. However, I took my lens back to the store due to a bad aperture diaphragm. After more than two months, they have still not fixed it.

Third party battery for the GH2

Having a spare battery is convenient. Without it, you cannot photograph anymore without going home and recharging the battery, should you run out of power.

Original spare batteries from Panasonic tend to be somewhat expensive. For the GH2, spare batteries have even been hard to find in certain markets.

One option is to buy a third party spare battery. They can be bought inexpensively from various auction sites. I decided to try one. It cost around US$20 including shipment from China.

The battery arrived very swiftly. It was packed well in a padded envelope, but beyond some bubble wrap, it did not come with any box for storing. Here is the original battery (on the left), and the third party battery (on the right):

The original battery comes with the official name, DMW-BLC12E.

On the reverse side, the third party battery, to the right, somewhat cryptically says: "For Pan.DMW-BLC12".

In use

The third party battery charges just like the original one. When inserted in the camera, though, there is one major difference which is easily spotted: You have no battery bars in the display anymore (using the third party battery on the right):

If you're going to use the battery for emergencies only, then this is no problem. But for normal use, it is a nuisance not to know how much power is left in the battery.

There is another consequence to this as well. When using the normal battery, the camera knows when the battery is almost depleted, and will not allow the user to take any more pictures. If recording a video, the camera will stop the recording, to allow for safely saving the footage already recorded.

The third party battery, however, does not allow the camera to see how much power is left. Hence, the power might go out during video recording, which could damage the whole recorded file, so that all your most recently filmed footage is lost. The same goes for images taken when the camera is almost out of power.

When the camera notes that there is not enough battery left, it leaves a message saying that the battery power is out, please recharge. With the third party battery, however, the camera simply uses up all the power until it is completely out, leaving the camera completely dead when having used up all the power. This is not a real problem, but can be confusing for some users.

Another side effect of using the non-original battery is that the camera loses the power save mode. So you must make sure to turn off the camera when not using it, otherwise the battery power will be drained too soon.

How much juice in the batteries?

I tried to compare how much video footage I could record with the two batteries. My camera is the European version, and can only record 30 minutes in one go. With the original batteries, I could start the video recording five times, with the last video being cut off after 24 minutes, due to too low battery. So the total recording time was 144 minutes, with the LCD display on all the time.

With the third party battery, I could only start three recordings. After that, the camera was completely dead, and did not respond until I replaced the battery with one that had some charge. The total recording time was 90 minutes.

This difference could be due to the new, third party battery not being worn in properly yet. Some say that batteries need to be used and recharged some times before reaching their optimal performance. I don't know.

Conclusion

The third party battery is good for emergency use. If your main battery goes empty, it would be good to have it in the camera bag to be able to continue using the camera until you can recharge the main battery.

But for critical use, it is not good. The battery could go empty while you are photographing or recording video, so that your most recent work is lost.

Software correction to the PL45?

One important aspect of the Micro Four Thirds system is the software correction to the images. Traditionally, lenses need to correct the images optically, so that the medium capturing the images sees the correct image. With the advent of digital imaging, though, the camera can do software based corrections to the image, adjusting for aspects that the lens does not correct.

This has the potential of making the lenses smaller and cheaper. Also, by allowing some aspects of the lens output to be adjusted with image processing, other aspects not possible to correct with software can be given more weight in the design process. This has the potential to give a better image quality. I think that software correction of lens output is a good thing, however, it remains a controversial issue.

One aspect which is corrected with a number of Micro Four Thirds lenses is geometrical distortion. I have explored this in a number of articles, here is one summarizing the effect for a number of lenses.

The other aspect corrected with some lenses, is some chromatic abberations. In my study, some chromatic abberations are corrected for lenses like the Lumix 8mm fisheye, the Lumix 20mm pancake and so on. Currently, this correction is only done when using Panasonic Micro Four Thirds cameras. At the time of writing, Olympus cameras do not perform the CA corrections.

Panasonic Leica 45mm f/2.8 macro

There is some rumor on the internet that Leica branded lenses are not corrected using software. This is clearly not true, since a number of Panasonic compact cameras feature Leica branded lenses that are corrected for geometric distortion. Examples include the Lumix LX3, and Lumix LX5, as well as the Leica branded counterparts.

But what about Leica branded interchangeable lenses? The Panasonic Leica 45mm f/2.8 macro lens (PL45) is the first Leica branded Micro Four Thirds lens. Are there any software based adjustments to the image output? Let's try to find out.

Geometric distortion correction

Here is an example image taken with the Panasonic Leica 45mm f/2.8 at f/2.8:

By looking at the uncorrected RAW, and comparing with the out of camera JPEG, we can easily see if there was any geometric distortion correction. Here are 100% crops from the lower left corner:

As we can see, they are identical in terms of geometric distortion. The RAW image contains about eight more pixels along the borders, which is why a bit more detail is visible from the wall and the leaves. I have previously written about this: Using RAW gives you approximately 1% more megapixels.

Corrections of Chromatic Abberations

So we conclude that there is no geometric distortions correction when using the PL45 lens. What about CA corrections? Usually, we see the CA artifacts most easily in the corners of the image frame, and where there is a huge contrast between light and dark elements. A typical place where this is visible, is where foliage meets the sky. So let's try to see in the upper right corner:

The exposure and white balance is not entirely the same in both crops, so it's not straight forward to compare them. But I think it is safe to conclude that there is no more or less CA artifacts in either image, thus indicating that there is no in camera CA correction performed for this lens.

In my previous study of some Panasonic lenses, it was easy to see that there was a correction of some CA artifacts.

Conclusion

Based on my study, I conclude that there is no software correction of the image when using the Panasonic Leica 45mm f/2.8 lens on Panasonic cameras.

This does not necessarily mean that no Leica branded Micro Four Thirds lenses will feature in camera adjustments to the output image. There is a newer Leica branded Panasonic Lumix 25mm f/1.4 lens. I have not tried it, and so I cannot say if it features this kind of image processing or not.

Note that this is in no way a criticism of using RAW images. There are many RAW image converters which will do the distortion correction automatically and seamlessly, and you will never notice that there was any geometric adjustment done at all. I am using the RAW images to visualize the initial image captured by the sensor, as it is the only way to access it.

Sharpness comparison, PL45 vs ZD50

At the moment, there are two medium long prime lenses that can be used on a Micro Four Thirds camera: The Panasonic Leica DG 45mm f/2.8 1:1 macro lens (PL45) and the Olympus Zuiko Digital 50mm f/2 1:2 macro lens (ZD50).

They are somewhat different. As you can see from the specifications, the PL45 has a better close focusing distance, hence, is more suitable as a macro lens. The ZD50, on the other hand, has a larger maximum aperture. For that reason, it could be better to use as a portrait lens.

The lenses are compared below. As you can clearly see, the PL45, to the left, is the smallest lens. The ZD50 requires an adapter for use on a Micro Four Thirds lens.

But what about their performance? Quite obviously, the PL45 is much better in terms of autofocus speed. The ZD50 could not autofocus at all with the first generation of Panasonic G series cameras, and with newer cameras like the GH2, the focus speed is barely usable at all.

I have compared the bokeh of the two lenses. In my experience, the bokeh of the PL45 is more smooth. The ZD50 has somewhat sharper edges around the out of focus rendering of highlights.

Also, I've tried to compare their sharpness. My study, which focused most on closeup focus distances, is probably not the best. But I believe it shows that the sharpness of the PL45 is a bit better. But there is certainly room for interpretation of the results.

It is also a well known fact that the ZD50 has some Chromatic Aberration artifacts. I have explored that here.

I have also compared the PL45 with the Nikon Z 105mm f/2.8 for the Nikon Z system. It very apparent in this review that the Nikon lens is way better. Sharpness comparison

I've tried to do a second test of their sharpness. This time, I focused on a distant object. I put the camera, the Panasonic GH2 on a tripod, used the lowest sensitivity available, ISO 160, turned off image stabilization, and used a two second shutter delay to avoid camera shake.

Here are the full images, taken with maximum aperture with both lenses. The images have been rescaled and sharpened:

PL45, f/2.8	ZD50, f/2

To better compare the sharpness, I have cut out 100% crops from both images at similar apertures.

Here are 100% crops from the centre of the image frame. Click on the image for a larger view:

And these crops are from the lower left corner of the image:

And from the upper right corner:

Conclusion

First of all, we see again that the Olympus 50mm f/2 lens has more chromatic aberration artifacts. The artifacts persist until stopping down to f/5.6. This is three stops smaller than the maximum aperture.

You can see the artifacts as purple fringing around high contrast areas, e.g., around the scaffolding when there is a bright sky in the background.

The CA artifacts only appear when having a large contrast in the image. In a portrait photo, you're not very likely to experience high contrasts, and hence this is not likely to be a big problem.

Vignetting does not appear to be a problem with the ZD50. However, keep in mind that at f/2.8, it is already stopped down one stop from the maximum aperture. The PL45 gives some vignetting at f/2.8. We see this in the corner crops: They are darker at f/2.8 than f/4 and f/5.6.

When it comes to the general sharpness and contrast, I think that the 100% views show the PL45 to be slightly better. I think that the PL45 shows the most pleasing results. But both are certainly very capable. Unless you are going to print the images to very large sizes, I cannot see that any of the two lenses will displease you.

Some users of the Micro Four Thirds system are still waiting for the portrait prime lens. They could be unhappy with the Panasonic 45mm f/2.8 macro, since it does not have the sufficiently large aperture they expect.

According to the Olympus lens roadmap, they are going to release a 50mm macro lens for the m4/3 format soon. If it has a maximum aperture of f/2, like the Four Thirds counterpart, then it may perform better as a portrait lens than the PL45.

Rumors also say that Olympus will release a non-macro lens with a focal length of 40-50mm, and a maximum aperture larger than f/2. This has later been specified as an Olympus 45mm f/1.8 lens. If so, this will be an even better candidate for the portrait prime. We shall see quite soon, as these lenses are announced.