Saturday, 26 July 2014

AF comparison, Lumix GH4 vs Nikon 1 V3

The Lumix GH4 and Nikon 1 V3 are similar cameras. They are both the high end mirrorless cameras from Panasonic and Nikon, respectively.

Also, both cameras have some specific technology aimed to improve what has been the achilles' heel of mirrorless cameras so far: The autofocus performance during video recording, and for moving subjects.

Traditionally, mirrorless cameras have set the focus by adjusting the focal distance back and forth until the image becomes the most contrasty, i.e., Contrast Detection Autofocus (CDAF). This means that the camera does not know if the correct focus if to the front, or to the back of the current focus distance, and may need to guess which way to start moving the focus. This can be quite annoying during video recording, as you would see the focus jog back and forth during the footage.

The Lumix GH4 aims to fix this through DFD technology, Depth From Defocus. This means that the camera is loaded with lens profiles, and knows the characteristics of the out of focus rendering (bokeh) for all the Panasonic lenses. Using this data, it should do a better job at guessing which way to start moving the focus, and how far.

The Nikon 1 V3, on the other hand, is using on-chip PDAF sensors. Essentially, this means replacing some of the ordinary light sensitive sensors with sensors that can "see" if the image is out of focus, and also in which direction, and how far. The aim is the same: To more quickly be able to set the correct focus, especially for moving objects.

In a previous article, I compared the Nikon 1 J1 with the Lumix GM1 in terms of autofocus. I found that the older Nikon 1 J1 won by a considerable margin, due to the PDAF. But then again, the Lumix GM1 does not implement the DFD technology, so let's see if the GH4 makes a difference.

In this article, I am comparing the GH4 with the V3, both using similar pancake wide angle lenses. The GH4 is mounted with the Lumix 14mm f/2.5, and the V3 is using the Nikon 1 10mm f/2.8. As the Nikon 1 system has a larger crop factor, both these lenses correspond to approximately 28mm in equivalent terms, i.e., a traditional wide angle lens.

In the test, I set the Lumix lens to f/4, while leaving the Nikon lens at f/2.8, so that they both have about the same Depth of Focus (DoF). A smaller sensor (the Nikon camera) leads to a deeper DoF. I used the base ISO, except where I noted ISO 1600 in the video. Both cameras were set to 1080p full HD video, and 60 frames per second.

Both cameras were mounted to a Desmond Mini Dual Camera Bracket, typically used for stereo photography.

Here are the results:

Based on the results I saw with the Lumix GM1, I was expecting to find that the Nikon camera completely outclassed the GH4. However, it appears that the Panasonic DFD technology does have some merit. The Nikon 1 V3 is generally the fastest to achieve the right focus, but the difference is not huge anymore. Also, there was one case where the Nikon camera struggled, at a close distance in low light.

Panasonic have stated that they do not want to venture into PDAF for the sake of improving the autofocus speed. They are worried that replacing the sensor pixels with PDAF sensors will deteriorate the image quality, especially for 4k video, where the full resolution is needed.

Panasonic say that CDAF, combined with better and faster image processing, will be just as good. And perhaps they are right: We see here that they have come a long way. Keep in mind that this test was done with 1080p HD video, though. In 4k mode, the GH4 autofocus is very slow, see my test here.

Nikon appeares to have gotten the PDAF implementation right from the start. In my previous test I found that the Nikon 1 J1 had a very impressive performance, despite being a first generation product, and the cheapest model, too.

I also note that the Nikon 1 V3 appears to have slightly less rolling shutter effect. I would attribute this to the smaller sensor size, and the faster image scanning. The Nikon 1 cameras are known for having a very fast scanning electronic shutter, making the mechanical shutter largely unneeded.

This is in contrast to Micro Four Thirds cameras. I've measured the electronic shutter of the GH4 to be scanning the picture in about 1/30s, but it is still way slower than the approximate 1/80s scan of the Nikon 1 cameras.

Sunday, 20 July 2014

Making a 4K video timelapse

The Lumix GH4 (my review) can be used to create 4K videos, but there are other ways as well. One way is to take normal resolution pictures with a camera that supports time lapses, and compose a video from them.

In this example, I used the Lumix GH4 to make the time lapse, but you could use any camera which supports it, for example the Lumix GM1 or the Lumix GX7.

I first set the camera on a tripod over my table, like this:

I'm using the Manfrotto 190XPROB tripod, which is useful since the column can be set horizontally. The ball head is Benro B-2, but most ball heads can be used here.

I used the Lumix G 14-42mm f/3.5-5.6 kit zoom lens at 14mm, and set the aperture to f/3.5. This was done mostly to avoid the aperture closing and opening for each shot, which is a somewhat annoying ticking sound. I prefocused, and then set the camera to manual focus (MF), to avoid the camera engaging the autofocus mechanism for each shot. I also used the electronic shutter mode to avoid the shutter noise.

To avoid having the images fill up too much space, I only used the "Basic JPEG" setting, see the symbol with the arrow pointing down into the three boxes on the centre top of the display. I also set ISO 400 to get about 1/60s exposure for each frame. In the example image you can see the focus peaking effect, the cyan outline of the box graphics to the lower left side.

I set the time lapse mode to take one picture every third second. I set the maximum image count to 3001. I don't need that many pictures, but I set a high figure just to get some slack, and I can stop the time lapse manually when I am done anyway.

Starting the timelapse and keeping it on while building gave me a total of 420 images, each taking about 2 megabytes. Each picture is a 16MP JPEG image in 4:3 aspect ratio. Here are some example frames:

Now, the pictures are in 4:3 aspect ratio, with a resolution of 4608x3456 pixels. For the 4K video, I need the 16:9 aspect ratio, with a resolution of 3840x2160 pixels. It would have been simpler if I had set the aspect ratio to 16:9 in the camera from the start. That way, I could have gotten away with just shrinking the pictures a bit.

However, I made sure to not use the upper part of the images, so I can just crop that off. Cropping and resizing can be done easily in the ImageMagick tool "convert", which I use in Linux. To get the right aspect ratio, I must crop off the upper 864 rows in each picture. Then, they should be resized to 3840x2160. I do all this with one command, like this, also adding a bit of sharpening. This command resizes all the images in a catalogue:

$ find . -name "*.JPG" -exec convert -crop 4608x2592+0+864 -resize 3840x2160 -unsharp 0.5x0.5+0.5+0.008 {} {}.PNG \;

Resizing all the 420 images took 3 hours, but then again, my computer is six years old.

The converted images are made into PNG images to avoid loss of quality in this process. To compose a video out of the still images, I used the program MEncoder, released together with MPlayer.

$ mencoder mf://*.PNG -mf fps=8:type=png -ovc x264 -x264encopts bitrate=24000:threads=2 -o video.mkv

Encoding the video file took about 10 minutes. I set 8 frames per second (FPS). And here is the output video:

In the time lapse, one can set a long delay between each shot, i.e., several minutes. If so, the camera enters a sleep mode between each shot. Setting manual focus still works, even if the lens focus is reset between each frame. Apparently, the camera has indexed the focus position.

Tuesday, 15 July 2014

Optional grip for the Lumix GM1

The Lumix GM1 is currently the smallest Micro Four Thirds camera. It has a quite trendy style, which mixes exposed aluminium with a retro look:

Despite the retro look, I am pleased to say that it does operate quite nicely. It is fairly easy to handle, although I find the rear wheel/four way controller combo to be a bit awkward to use, and would have preferred to have a thumb dial like most other cameras.

However, it really needs a better grip. And Panasonic is producing just that, the Panasonic DMW-HGR1S grip:

So what is it like?


Most of the grip is made of aluminium, and it is quite light. The screw is made of steel. On the inside, there are some plastic insets, which are designed to avoid having the metal from the grip rub against the camera body. I think this is a nice touch:

The metal surfaces are very nicely machined and finished. Here is the grip, which has a regular, extruded pattern:

The smooth surfaces appear to have a bead blasted finish, which is very smooth and nice:

And herein lies the problem: The grip is just too smooth, with no features:

From the underside, we see that there is no extra tripod attachment point, unlike many other grips you might find for other cameras. So you cannot put the camera on a tripod, if you use the grip.

Further, the grip completely blocks the battery and SD card compartment. So to replace or recharge the battery, you must first remove the grip. This is quite awkward.

Here is the grip mounted to the camera:

In use

Without the grip, you must squeeze the camera between the thumb and the fingers. As seen from the top:

Not having any grip surface on the front, the finger has nothing to hold on to, giving a not very confident grip:

With the grip mounted, the finger has the ribbed aluminium surface to hold on to, and I feel that I can handle the camera in a much better and solid way:

On the rear side, there is a small grip surface under the thumb:


I think the optional grip allows me to handle the camera in a more confident way. Without the grip, I feel like I might easily lose the camera out of my hand.

The Panasonic DMW-HGR1S is very nicely finished, and feels very solid. Given the high quality of the finish, I don't think the price is overly high. Now, whether or not you actually need this level of finish is another question. I certainly don't need this from a grip.

The major downside is that the grip makes the camera less functional. You can no longer mount the camera to a tripod. And you must remove the grip to recharge the battery or access the SD card.

There are some alternative products available. For example, the wood grip from J.B. Camera Design, which supports mounting on a tripod, and changing the battery and SD card.

Wednesday, 9 July 2014

GM1 vs Nikon 1 J1 autofocus during video comparison

Looking at the Nikon 1 J1 and Lumix GM1, it is clear that they are very similar:

Both are quite compact mirrorless cameras without a grip, without a flash shoe, and with fixed LCD screens. You can't put an eye level viewfinder on any of them. Both are mounted with rather similar wide angle pancake lenses in the picture above.

Also, since the Nikon 1 J1 is the very first generation mirrorless camera from Nikon, and the cheapest, it may look strange to pitch it against the Lumix GM1, which is a new, premium camera from Panasonic, widely seen as the leaders in large sensor video.

However, the Nikon 1 family of mirrorless cameras has something which Panasonic has never implemented: On sensor PDAF sensors. Panasonic have decided to rely on CDAF, which requires more image processing power to function well, but has the advantage of not sacrificing any pixels for PDAF sensors. In theory, PDAF should be able to give a much better AF-C performance, and AF performance during video recording.

You may also think that the Lumix GM1 is not a very good video camera, as it appears to be styled in a classic way. However, in my experience, it performs just as well as, or even better than, the GH3 in terms of image quality, quality of ETC video, and AF during video. So the GM1 is pretty much state of the art, except for the fact that it doesn't have 50/60 FPS 1080p video, and of course, it doesn't have 4K video.

To see how the Nikon 1 J1 camera performs in terms of autofocus, I mounted both to a Desmond Mini Dual Camera Bracket, typically used for stereo photography. The lenses are the Lumix 14mm f/2.5 and the Nikon 1 10mm f/2.8. I set both lenses to f/2.8.

For the test videos, I set the ISO to 200, except when otherwise noted. Here are the results:

As you see, the Nikon 1 J1, despite being two years older and cheaper, is way better in terms of acquiring focus. Even when panning quickly, it gets the focus right almost instantaneously, and even in poor light and high ISO.

I would say that Nikon is the only company which got PDAF for mirrorless cameras right from the beginning. The AF performance is just amazing.

Now, these videos are not typical of how people normally use video, but they illustrate the strength of the Nikon 1 system. Also, the 27mm equivalent wide angle pancake is not the one which needs fast AF the most.

However, with the recently launched Nikon 1 70-300mm f/4.5-5.6 lens, the Nikon 1 system will be the first to be useful for birders.

At no time before has there been a so small and light interchangeable lens system with this reach: More than 800mm eqvivalent. And with the fantastic AF performance of the system, this lens should be useful for catching birds in flight (BIF). Especially with a camera like the Nikon 1 V3, which has a proper grip and EVF.

Sunday, 6 July 2014

Lumix GM1 mechanical shutter

The Lumix GM1 may look like a small and insignificant camera, but in fact it has some interesting innovations within Micro Four Thirds. It has two shutters: The electronic shutter, which is faster than the first generation, but still slow enough to give some rolling shutter artifacts.

Then there is the mechanical shutter. It is of the "electronic front curtain type", which means that the exposure is started electronically, without a mechanical curtain. This is good, it means that there is less risk of shutter shock, that the shutter causes camera shake and blurry images. It is also less audible, and there is less shutter wear.

The mechanical shutter is also unusually slow. While this also keeps down the noise, it is not really a good thing, of course. Due to the slow mechanical shutter, the flash sync speed is limited to 1/50s, which is a quite poor specification. This design choice was probably implemented by Panasonic to keep the size and noise down.

The slow moving mechanical curtain is possible to record using a high speed video camera.

Enter the Nikon 1 J1. Even if it was the first generation Nikon 1 camera, and the entry model, it is capable of 1200 frames per second video. At a resolution of only 320x120 pixels, this is more of a gimmick, but it can be a fun gimmick. The two cameras are seen below, both with wide angle prime pancake lenses:

One problem with video recording the moving mechanical shutter of the Lumix GM1, is that the camera will only use the electronic shutter when a lens is not mounted. So you cannot trigger the mechanical shutter without a lens mounted. This is probably for protection, to avoid jamming the curtain blades.

However, the shutter cycles once every time you power on the camera, and this can be used to record the shutter travelling.

Here is an animation showing the travelling GM1 shutter:

The shutter opens over about 15 frames, taken at 1200 frames per second in this high speed video. This means that the speed of the shutter curtain is about 15/1200s, or 1/75s. This is close to my previous measurement of the mechanical shutter speed of about 1/100s. It is also faster than the flash sync speed of 1/50s, which is reasonable.

We also see that the shutter curtains resonate a bit when moving to the fully closed position. Hopefully, the shutter curtains are dampened in a way so that this does not cause wear over time.


The high speed video mode of the Nikon 1 J1 may seem like a gimmick, but it could be used to produce interesting insight about the workings of the Lumix GM1 camera.

By the way, the Nikon 1 J-series of cameras do away with the mechanical shutters completely, relying only on an electronic shutter. The electronic shutter speed of the Nikon 1 cameras is 1/80s, about twice as fast as that of the premium M4/3 camera Lumix GH4 (my review).

Thursday, 3 July 2014

Olympus 9mm: Fisheye vs Rectilinear

Olympus now has two lenses which include the 9mm focal range: The Olympus 9mm f/8 fisheye (my review) and the Olympus 9-18mm f/4-5.6 wide angle zoom lens. The first is a fisheye lens, and hence, it has significant barrel distortion. The second is a rectilinear wide angle zoom lens.

But beyond that, do they give you a different field of view? Below is the 9mm fisheye lens, with the Four Thirds version of the 9-18mm zoom:

Taking the same picture with both lenses yields these variants:

So, as you can see, even if both lenses are rated at 9mm, they give a quite different field of view. The fisheye lens is much wider. On the other hand, outside of the centre, it is quite distorted.

Both images are quite impressively sharp. Here are 100% crops from the centre, and from the lower left corner to illustrate this:

And, despite what you might expect, notice that the proportions of the man sitting on the bench in the corner actually look more realistic in the fisheye version of the image. A very wide rectilinear lens stretches the corners a lot, which makes the picture look less realistic.

Of course, the barrel distortion of the fisheye lens is also unrealistic, so in this case it is a matter of picking the kind of realism you prefer.


You can use software correction to defish the fisheye image. This is a process which makes the distorted image more rectilinear. I'm using the free software Hugin for this process. Here is how:

First, select "Load image", and choose a JPEG fisheye image.

Next, you must specify the type of lens you are using. Select "Full Frame Fisheye" (a fisheye lens which fills the whole frame), then the focal length (9mm), and the crop factor, 2x:

THe next point is to select the target projection. I have chosen Rectilinear here, but you can experiment with other projections. Some like to use the Panini projection.

To bring up the GUI for the final stage, select "Advanced interface":

Then, to get the biggest possible resolution, 6872x4215 pixels in this case, click on "Calculate Optimal Size". Then click on "Stitch" to process the final image. Before you can do that, Hugin will ask you to save the project file, a file with a .PTO extension. Then, you can save the final, defished image. Select TIFF image format for the best quality, for further image processing.

Here is what the final output looks like:

Compare it with the picture taken using the 9-18mm zoom lens at 9mm:

So, as you see, using the small and cheap 9mm fisheye lens, you can get very wide rectilinear images, wider than the widest rectilinear Olympus lens. And at a much lower price! Sure, the corners are a bit unsharp, but even if you do crop the image some, it is still very wide.

My conclusion is that this is a fun lens to have, at a low price.

Sunday, 29 June 2014

Lumix GH4 Review

The big news from Panasonic this year is the Lumix GH4. There is a tradition that the version number four is dropped when incrementing a camera model name. For example, there was never a Lumix G4 or GF4. The reason for this is that the word for "four" rhymes with the word for "death" or "disease" in some Asian languages.

However, there are two reasons why Panasonic still used the model name "GH4": One is that professional cameras often still carry the number four. We have the professional Nikon D4, for example. The manufacturer probably reasons that the users of a professional camera is less likely to be superstitious.

The other reason is that the main new feature of the GH4 is 4K video. So it makes good sense to use the model name GH4.

From the outside, the GH4 looks very much like the predecessor GH3:

The body is molded slightly differently over the flash, but other than that, the shape of the camera bodies is pretty much identical. The button layout is also the same. However, there are some small, but important differences.

Not visible in this picture, the inside of the grip is molded slightly differently. When holding the grip, you can notice that there is an additional ridge which gives a more confident grip for your fingers.

On the left shoulder, there is the drive mode wheel:

Lumix GH3 (left) and Lumix GH4 (right)

The drive mode wheel gains another setting for time lapse mode. But more important, for me anyway, is that it has become more stiff. With the GH3, the drive mode wheel would often be dislocated as I took the camera out of the bag, but that just doesn't happen anymore with the GH4. This little details is important for me.

On the right hand shoulder, we again have the same layout. This time, the mode dial has lost one setting, the scene modes. I guess most people would agree that scene modes don't belong on a professional camera anyway, so I don't see this as any loss.

Lumix GH3 (left) and Lumix GH4 (right)

Also, the mode dial of the GH4 gains a locking function. Press the top button once, and the model dial is locked. Press it one more time, and it is unlocked. The mechanism is the same as the one found on retractable ballpoint pens.

The SD card door looks the same, but again, it has been improved. On the GH3, the door would easily open by a mistake when taking the camera out of the bag, but the GH4 implements more friction in the locking mechanism, so that this doesn't happen. Good stuff!

Also, while the red movie button looks just the same, the new one has a better feel to it. You feel like you have more control over it. With the GH3, I had to just press the button hard and hope the camera reacted. With the GH4, the button gives me better feedback.

The GH4 gains a new drive mode for time lapsesand loses the mode setting for scenes
The ISO button gets one more dot, making it easier to feelThe front Lumix logo loses the cheesey gold colour

Even if the top side of the flash is molded differently, the flash itself has the same pop up mechanism, and provides the same coverage as before.


The GH4 gets a bigger rubber eyecup around the EVF. This is a good thing. After all, one typical use for the EVF is in strong sun light. And a bigger eye cup better protects against the sun, making it more probably that you can actually use the EVF. This is especially good news for people who wear glasses.

Lumix GH3 (left) and Lumix GH4 (right)

Even if the viewfinder optics appear the same from the outside, I find the GH4 EVF to be a solid improvement over the GH3. Even when wearing glasses, I can see more of the image at once, and much more clearly. It has a 35% higher resolution, as well.

In use

The Lumix GH2 had a big flaw: The buffer clearing speed was horrible. If you took a series of pictures in RAW, the camera would clog up for an annoying period while writing to the SD card, even if you had a very fast SD card. The GH3 fixed this, and the GH4 is even faster.

Speaking of SD cards, I've found that a Sandisk Extreme 45MB/s SD card is good enough for all video modes. However, if you plan on using the 200Mbps All-Intra mode a lot, you could invest in the even faster Sandisk Extreme Pro 95MB/s card.

The most recent and very expensive Sandisk Extreme Pro UHS II cards are not needed, in my experience. Read mode about my test here.


The Lumix GH4 has a new sensor, compared with the GH3. However, the image quality improvements are not massive. You should notice somewhat cleaner images at high ISO, and there is a slight improvement of the dynamic range.

One significant improvement is the mechanical shutter unit. It is faster, and slightly less audible. This gives you a higher frames per second rate, and it also ups the flash sync speed from 1/160s to 1/250s. The maximum shutter speed also increases from 1/4000s to 1/8000s.

Another improvement is the electronic shutter mode. The GH3 had a very slow electronic shutter readout speed of 1/10s. This gave very severe rolling shutter artefacts, see some examples here.

With the GH4, this readout speed increases to 1/30s. This is still not fast enough to be safe against all rolling shutter artefacts, but this should be less of an issue.

The downside of the new electronic shutter implementation is that it drops two (out of 12) bits when reading of the sensor values. This gives you less dynamic range when using the electronic shutter. It is not much of an issue, you would typically only notice more noise if you lift the shadows a lot in post processing. Read more about this here. So to get the best possible image quality, use the mechanical shutter, not the electronic shutter. For most real life situations, though, the difference is very small.


The Lumix GH4 gets faster video processing, allowing for faster autofocus during video recording.

There is a comparion of the video speed with some prime lenses here, and with the two f/2.8 zoom lenses here. The GH4 generally performs better, as you would expect.

One thing to notice, is that the autofocus performance while recording 4K video is very poor. So if you need to rely on continuous autofocus during video recording, go for the 1080p mode. That will give much more dependable autofocus, and a higher framerate to boot.

But 4K video is the big news. The Lumix GH4 is the first mirrorless camera to support 4K video.

4096x2160 (17:9, 1.85, Cinema 4K)24p
3840x2160 (16:9)25p, 30p
1920x1080 (16:9)24p, 25p, 30p, 50p, 60p
1280x720 (16:9)24p, 25p, 30p
640x480 (4:3)25p, 30p

There is a drawback with 4K video, though, the camera only uses parts of the sensor at this resolution, as illustrated below:

As the Lumix GH4 does not have the multi aspect ratio sensor, just like the Lumix GH3, there is a crop factor when switching from photos (4:3) to 1080p video (16:9). The sensor diagonal is 8% shorter in 16:9 than 4:3, meaning that there is an additional crop factor of 1+8% = 1.08. So in 1080p video, a 14mm lens behaves like a 15mm lens in terms of the diagonal field of view. This is just like the Lumix GH3.

With the Lumix GH4 in 4K video mode, though, the crop factor is much larger. In 4K mode, multiply the focal length with 1.31, and in Cinema 4K mode, use 1.24. So the 14mm lens becomes equivalent to 18mm and 17mm, respectively. See the table below:

ResolutionSensor area usedDiagonalCrop factor
Photos (4:3)4608x345657601
1920x1080 (16:9, Full HD)4608x259252871.08
4096x2160 (17:9, 1.85, Cinema 4K)4096x216046311.24
3840x2160 (16:9, 4K)3860x216044061.31
1920x1080 (16:9, Full HD, ETC mode)1920x108022032.6

So all your lenses become "more narrow" when using the 4K feature. The reason for using only a part of the sensor area for 4K video is processing power: If the camera would use the whole sensor area and then scale it down to around 4000 pixels horizontally for each frame, this would require far too much processing. A high quality rescale, to avoid artefacts, requires a lot of CPU resources.

Another welcome news, is that the Lumix GH4 is the first Panasonic Micro Four Thirds camera to be multi region, in the sense that it can record both 25p and 50p (PAL region) and 30p and 60p (NTSC region) using the same unit. The camera requires a reboot when switching region.

This means that you can choose between using 50p or 60p (for full HD video capture), and between 25p and 30p for 4K video capture. Previously, you were only able to use one of them, depending on where you bought the camera in the first place.

Normally, you would want to use the "correct" setting for your own location. For example, if you are in a PAL region, and use 30p, you could risk getting an interference between the video framerate and the frequency of artificial light, causing an annoying flickering. Here is a demonstration of how this might look like. However, having the choice between 25p and 30p is very good.

The Lumix GH4 is the first Panasonic M4/3 camera to handle 50/60 FPS combined with the video ETC mode. The GH3 could only do ETC in 24/25/30 FPS.

There are other improvements as well. For example, the GH4 features a zebra pattern to warn against overexposure during video recording, and also implements focus peaking. See focus peaking demonstrated with the Sony NEX-3N.

The competition

Here's the thing: Not many cameras feature 4K video yet. If you want an interchangeable lens camera with 4K video, the only other choice is the Canon EOS 1D C, which is a rather large DSLR camera. There are also the professional RED digital video cameras, but they are out of the scope for the consumer market.

Blackmagic say they have a 4K video camera in the works, however, it has been delayed a lot. In the mean time, they have the Cinema Camera capable of 2.5K video at a high dynamic range.

About a year ago Nikon said that they would implement 4K video in their Nikon 1 range of mirrorless cameras. However, nothing of the sort has surfaced, and the Nikon 1 range does not appear to be doing well in the market.

Looking at the non-interchangeable lens market, there are some offerings: The Sony FDR-AX1 is large and expensive, but you can buy it now. There is also a less expensive Sony FDR-AX100 expected to ship in March. And from JVC, the GY-HMQ10. All of these have fairly small sensors, though, compared with the Lumix GH4.

CameraForm factorSensor sizeCrop factorMax FPSPriceAvailable
Sony A7sDSLRFull Frame1.130, needs external recorder$2.500September 2014
Canon EOS 1D CLarge DSLRAPS-H (4K mode)1.525$12.000Now
Blackmagic Production CameraCompact, tripod mounted Super 35mm1.530$3000February 2014
Lumix GH4Small DSLRFour Thirds2.5 (4K mode)30$1900May 2014
Lumix FZ1000DSLR like superzoom1''330$900June 2014
Lumix LX8Premium Compact1''330$800August 2014
Sony FDR-AX100Small Camcorder1''330$2000March 2014
Sony FDR-AX1Camcorder1/2.3''5.260$4500Now
JVC GY-HMQ10Camcorder1/2.3''5.260$5000Now
GoPro Hero 3+ Black edAction camera1/2.5''5.715$400Now

Shortly after Panasonic announced the Lumix GH4, Blackmagic said it would ship it's "Production Camera", which is 4K capable. It is going to be sold at USD 3000, 25% less than originally announced. It has a Canon EF mount capable of electronic aperture control. Compared with the GH4, you get a slightly larger sensor, but a much less ergonomic camera body. It essentially must be tripod mounted. You also lose the autofocus, compared with the GH4.

The Sony FDR-AX100 is probably the closest competitor to the Lumix GH4, with a similar price, and a slightly smaller sensor. It comes with a non-interchangeable lens, though, and cannot use the host of Micro Four Thirds and legacy lenses that you can mount on the GH4. Choosing between the Sony FDR-AX100 and the GH4 comes down to what type of camera body you want, and whether you want to be able to change lenses or not.

The Sony A7s was announced in April 2014, and offers 4K video from a Full Frame sensor, almost without any cropping. You lose some pixels on either side, bringing the crop factor to approx 1.1. The downside is that it does not record 4K video internally, you need an external HDMI recorder, like the Atomos Shogun, priced at around US$2000, to be available around the end of 2014.

One of the reasons why Sony used a 12MP sensor on the Sony A7s is just this: To be able to do 4K video with very little cropping. Had they used their 24MP sensor, they would have needed to record 4K video off the centre 8MP portion of the sensor, or to sample the 4K video from individual pixels in a grid off the sensor surface.

Cropping has negative side effects, of course, and the sampling can lead to line skipping artefacts. A quality down scaling from a larger resolution sensor to 4K video is very computer intensive, and cannot be done in real time by any consumer camera with todays technology level. That is one of the reasons why they chose a low resolution 12MP sensor for the Sony A7s.

More recently, Panasonic announced the Lumix FZ1000 bridge superzoom camera. With a one inch sensor and a healthy 24-400mm equivalent zoom lens, it is designed to go head to head against the Sony RX10. The Lumix camera sells at a lower price, and has the 2014 must have feature, 4K video.

We also expect Panasonic to release their new premium compact camera Lumix LX8 in July 2014. It will also have a one inch sensor, and features 4K video. Just like the predecessor Lumix LX7, it will have a fast zoom lens.


The Lumix GH4 is a game changer. It is still the only 4K video capable mirrorless interchangeable lens camera. It is very ergonomic, compact, and cheap. Also, there is a healthy lineup of native lenses, plus a host of legacy lenses that you can use with an adapter.

All of this makes it the perfect camera for serious amateurs and indie movie makers.

Thursday, 19 June 2014

Olympus 9mm f/8 fisheye review

The Olympus 9mm f/8 fisheye is the second in the series of non-Zuiko branded "toy" body lens cap lenses. The first was the Olympus 15mm f/8. Both are very compact lenses, with a fixed f/8 aperture, and a small lever which operates a lens cap, and the focus.

Here is the 9mm fisheye lens, with the supplied rear lens cap. The lens comes in a simple cardboard box, padded with a bubble wrap bag:

Physical and in use

The lens is very light, and is made from a hard plastic material. Turning the lever on the front opens up the front lens cover, exposing the lens. Turning it further controls the focus. There are two "click stops" on the focus scale: One for "infinity", and one dot for "distant" focus, as explained in the manual. These two are quite similar in terms of focus distance.

I would advice to use the "infinity" stop if you have no foreground items, and the second dot stop if you have some foreground objects. For focus closer than about 1 meter, you should start turning the lever closer to 0.2m.

The lever is quite loose, and you easily risk knocking it out of place accidentally. If you change the focus, you'll see that the whole lens assembly moves back and forth. So this lens does not have an internal focus, is has a classic focus mechanism.

On the rear side, you see that the exit pupil is much larger than the front entry pupil. This is probably to make the lens sufficiently telecentric, so that the light rays do not reach the sensor corners at a too steep angle.

There is no serial number on the lens, and no electronic contacts. So to use the lens, you need to enable the "Shoot without lens" option, which tells the camera to allow taking pictures, even if it does not sense any electronic lens being present.

The lens is a good match for the compact Lumix GM1 camera, making it truly pocketable:

The max aperture is f/8, which does not sound very impressive. However, for daylight use, this is perfectly fine, no problem at all. For indoor use, though, f/8 can be too dim. So indoors, you may need to use a flash.

Image quality

To check the image quality, it is a good idea to compare it with its peers. Below it is seen with the Wanderlust Pinwide pinhole (my review) and the Samyang 7.5mm f/3.5 fisheye lens (my review):

The Wanderlust Pinwide pinhole is similar in the sense that it is also a "fun novelty item", and is very compact, and wide. The Samyang 7.5mm f/3.5 fisheye lens is a very good fisheye lens at a reasonable price, one of the real bargains of the Micro Four Thirds system.

Here is the same building photographed with the three lenses (click for larger images):

From these images, you clearly see that the Olympus 9mm f/8 fisheye is not a true fisheye lens: It doesn't have a full 180° diagonal field of view. The diagonal field of view is about 140°.

Further, we also see that the Samyang 7.5mm f/3.5 is way better in terms of image quality. Here are some 100% crops to illustrate this. From the centre:

And from the lower left corner:

In the centre, the Olympus 9mm f/8 fisheye is quite sharp indeed. However, in the corners, the sharpness is rather poor. But all in all, the lens is certainly fully usable.

With a wide lens, you will often experience to have the sun inside the frame. Hence, it is important that the lens handles flare well. Here's how it does:

As you see, there is quite some flare, but it is not too bad. The flare looks quite ok, and even charming, one might say.

LensOlympus 9mm f/8 fisheyeSamyang 7.5mm f/3.5 fisheye
Minimum focus

The lens has a quite close minimum focus distance: 0.2m. In this example, I have the corner of the traffic sign about 3cm from the front of the lens, with the focus set to the minimum:

Here, the focus is set to infinity:

Looking at the top left corner, we see that there are quite some chromatic aberration artefacts in the corners, click for a larger image:

Alternative lens

Beyond the Samyang 7.5mm fisheye, also marketed as Bower, Rokinon, there is the Lumix G 8mm f/3.5 fisheye (my review). It is seen below, together with the Olympus fisheye lens:

Except for the fact that both lenses are very wide and have a significant barrel distortion, they are very different. The Lumix G 8mm is quite expensive, around US$700.

The Lumix lens has autofocus. However, the autofocus is normally not needed for a wide fisheye lens. Autofocus can come in handy if you are making cute closeup pictures of pets, but otherwise, it is not a big deal.

The Lumix lens has a full 180° diagonal field of view. In terms of image quality, it is not quite as good as the much cheaper Samyang lens, according to my comparison. Also, the Lumix lens has slightly more barrel distortion, see a comparison here. To top it off, I also find that the Samyang is less susceptible to flare. This makes the Samyang lens a good deal, and the Lumix lens less so.


The Olympus 9mm f/8 fisheye is certainly an interesting lens. Mostly, it is interesting due to the size: It makes your camera very compact indeed.

Optically, the image quality is ok, but hardly impressive. If you seriously want to test a fisheye lens, then I would wholeheartedly recommend the Samyang 7.5mm f/3.5 fisheye lens (my review), which has a much wider field of view, very good optical properties, and is easy and fun to use.

The Olympus 9mm f/8 fisheye still has its place, as a fun, cheap, novelty lens, which takes good images. It is not a toy lens, I would say. It has normal glass lens elements, and two of them even have aspherical surfaces.

Example images

These are JPEG images straight out of the camera, the Lumix GH4. Click for larger images.

f/8, 1/160s, ISO 800:

f/8, 1/125s, ISO 200:

Example video

Here is a video recorded with the Lumix GH4. The first segment is done using 1080p, and the second at 4k resolution. With the extra 4k crop, the 9mm lens becomes a reasonably wide, almost rectilinear lens. In 4k resolution on the Lumix GH4, you barely see that there is barrel distortion, due to the camera cropping off the border.