Sony NEX-3N vs Lumix GF3

The Sony NEX-3N and the Panasonic Lumix GF3 are similar camera models. They are both made to be as small as possible, and come with a collapsible power zoom kit lens:



Comparing them is not entirely fair, though, as there is some age difference. The Sony NEX 3N was released in February 2013, while the GF3 was launched in June 2011. The GF3 has been replaced by the Lumix GF5 in April 2012, and then later by the Lumix GF6 in April 2013.

The GF5 is basically the same camera as the GF3, except that it adds a rubber grip surface on the front, which is actually a big difference. The GF6 is a big improvement, though, with a newer sensor, better ergonomics, and a tiltable rear LCD.

In this article, I compare the video output of the two cameras. Both were set to the base ISO, 1080p, 25fps. I used the Lumix X PZ 14-42mm f/3.5-5.6 at 14mm f/3.5, while the Sony NEX also had the kit zoom lens Sony 16-50mm PZ lens was set to 20mm, to match the field of view of the Lumix lens.

Here is the comparison:



Here are also some still images for comparison:

Sony NEX 3N	Lumix GF3
Sony NEX 3N	Lumix GF3

Test results

Even if the Sony NEX 3N is two years newer than the Lumix GF3, I still find that the GF3 outperforms the 3N in terms of video performance. It focuses faster, it generally exposes better, and has better colours. The startup delay is also significantly shorter with the GF3. The Sony NEX appears to have the upper hand by a small margin when it comes to handling of rolling shutter, but that is hardly a problem with either of them.

I find the same conclusion with the still images: The Lumix GF3 generally exposes better, and I like the out of camera colours better. If I had spent some time editing the images with a RAW converter, I think I would get better images from the Sony NEX 3N, though.

Autofocus

Overall, it is fair to say the Lumix GF3, the oldest model, focuses the fastest by a good margin. This applies during video recording, as shown in the video above, and also for still image use. I found this to be true especially when using the long end of the zoom lens.

Both cameras use CDAF technology for focusing. The speed of CDAF during video largely comes down to image processing power. Hence, it is not unexpected that the premium camera Panasonic GH3 outperforms them both in this aspect. I have tested the AF during video here, and the GH3 performance is very impressive.

Some newer and more expensive Sony NEX cameras feature on-sensor PDAF. This will probably give better autofocus performance. For example, the Sony NEX 5R has this feature. However, the real life benefits of on-sensor PDAF is somewhat uncertain.

Operation

The power zoom lever is longer on the Sony NEX lens, spanning a larger part of the lens diameter, so that it can be easily operated both in landscape and portrait mode. That is not as easy with the Lumix X PZ 14-42mm, having only a small lever.

On the other hand, though, the Lumix lens has two zoom speeds, while the Sony lens only operates at one zoom speed. This makes a huge difference, and it is much more pleasant to use the Lumix lens when zooming. Especially when taking still images, it is very awkward and annoying to try to get the desired field of view with the Sony camera, by pushing the zoom lever briefly to get the change you need. On the Lumix camera, just pushing the zoom lever slightly operates the motor at the slowest speed, in which case small and accurate adjustments are very easy to make.

When it comes to video recording, the Sony camera has one clear advantage over the Panasonic cameras: It displays the exposure settings in the display while recording. A very annoying feature of the Panasonic Micro Four Thirds cameras, even the "video optimized" GH3, do not display the aperture, shutter speed, and ISO settings while recording videos. Unless you set these manually, that is. Seeing the exposure settings while recording makes it easier to use the Sony NEX 3N for video, in my opinion.

In general, the Sony camera feels a bit less responsive, perhaps this feeling is magnified by the somewhat slower autofocus, especially with the lens in the longer end of the focal range.

The Sony camera adds a tilting LCD display, which I find very useful. When having the camera in a neck strap, one can keep it at waist level, while looking down into the tilted display. This way, it is easy to achieve stable video recording. With the GF3, one must keep the camera at arm's length in front of the face, where it is quite hard to hold steadily. The newer Lumix GF6 also adds a tilting LCD display, so Panasonic is aware of this problem.

Conclusion

The Sony NEX-3N is an interesting camera, with a large APS-C sensor in a very small body, and a compact and light power zoom lens. I find that it does not operate as smoothly as the older GF3, though, and it does not perform as well when it comes to video colours and autofocus. The camera feels solid, but the lens wobbles a bit when extended. This is in contrast with the Lumix X PZ 14-42mm lens, which is rock solid even when extended.

In terms of pricing, the Sony NEX-3N with the power zoom kit lens is very competitively priced. The lens extends to 16mm in the wide end, corresponding to 24mm equivalent, which is more interesting than the focal length range of the Lumix lens. All in all, the Sony camera kit is quite interesting for people who want to get started with mirrorless cameras at a reasonable cost.

GH2 vs GH3 video quality comparison

When Panasonic released the GH3, it was expected to raise the bar even further in terms of video quality. To compare it against the GH2, I connected both cameras to a piece of wood, using Manfrotto Superclamps, so that they would record the same scenery for comparison.



On both cameras, I used the Lumix G 14mm f/2.5 pancake lens, a favourite of mine. I focused on "infinity", and then set both cameras to manual focus. The lenses were set to f/5.6 for the best sharpness, and I used the base ISO on both cameras. With the ambient lighting, the shutter speed was usually around 1/120s. Both cameras had the same settings in terms of sharpening and saturation. It was all recorded in 1080p, 25fps.

Even if the cameras have identical lenses mounted, they still have different field of view during video recording. This is due to only the GH2 having the an over-sized, multi aspect sensor, giving a wider field of view in video mode.

Here are the videos combined, for easy comparison:



Some may doubt that the quality of the YouTube rendering of the video is sufficient to really tell the difference between the cameras. I agree with that, and to assist in comparison, I uploaded parts of the video at 200% size, which probably makes the video image quality easier to assess. And I made some 100% crops from the original out of camera video files, uncompressed in PNG format below:





This last image comparison is from the ISO 1600 footage:

Conclusion

Just like I have concluded previously, the GH3 features somewhat less rolling shutter artefacts in video mode. Further, I think it looks like the GH3 handles high contrast better, and the overall sharpness of the video stream is better. Not unexpected, since the GH3 can record at up to 72Mbps bitrate, as compared with 24Mbps for the GH2. I used 50Mbps with the GH3 here, though. Of course, the bitrate is not everything, the sensor, AA filter, downsampling algorihm and compression algorithm are also important.

I also like the colours of the GH3 better. At high ISO, the GH3 does provide more details.

As far as I can see, the GH3 does deliver on the promise of delivering even better video quality than the predecessor GH2.

2x Fisheye on a bicycle

It so happens that I have both the fisheye lenses available for Micro Four Thirds at this time. I bought the original Lumix G 8mm f/3.5 fisheye when it was available. It is a fine lens, for sure, with good sharpness even in the corners.

The Samyang 7.5mm f/3.5 fisheye lens did interest me, and I decided to pick that one up as well. It is much cheaper, and performs even better optically, in my experience. The Lumix lens can be better when photographing close items, like closer than around 30cm (one foot). Then, autofocus is useful. Otherwise, I generally use the Samyang lens now.

But having both at the same time can also be useful. Since I have both the GH1 and GH2 cameras, I can use both lenses at the same time. Mounting them both to my bicycle using Manfrotto Superclamps and ballheads, I can record the scenery passing by from two angles, which can make some interesting footage:

Here is the footage I ended up with, after editing the video. I'll get back to the details of how I edited it later in this article:



Front camera

Pointing forwards, I have the GH1 camera with the Lumix G 8mm f/3.5 fisheye lens. The camera is set to auto-ISO. With the exposure set to f/3.5, 1/25s, the camera has picked the maximum ISO 1600 for most of the ride, which is still a bit too low, leaving the footage a bit underexposed. I pre-focused at about 1m distance, and left the autofocus off. The camera records at 25fps 1080p.

Rear camera

Pointing backwards, I have the GH2 camera with the Samyang 7.5mm f/3.5 fisheye lens lens. I used the same settings as for the GH1 camera above. However, the auto-ISO goes to 3200 for videos, and hence, the rear camera has a better chance at capturing a more correct exposure.

In my experience, both cameras will consistently underexpose when using the Samyang lens at night, with high contrast. So I dialed in +1 1/3 exposure compensation.

Video editing

First of all, I had to synchronize both video streams, which was quite difficult. In retrospect, I should have clapped my hands in front of both cameras, to have a more clear point of reference.

Here you can see both videos in the Kdenlive video editing software timeline. The GH1 footage is on the top. I'm using the audio from the GH2, pointing backwards.

Then, I wanted to fit both videos into one single frame. This was achieved by cutting off the top and bottom of the original frames, and then compressing the rest by about 20%. To do this, I use the "Scale and Tilt" effect in Kdenlive, with these parameters:

Here is an illustration of an example image frame before and after cropping and scaling:

After halving the vertical size of each stream, I can fit both of them into one 1920x1080 video frame.

Conclusion

One would think that having two lenses that are virtually equal is a waste of money, but it can give you some creative possibility.

After seeing the resulting video, I think I should have cut it much shorter. I doubt that many will want to see the whole thing, as it is too long.

GH2, does ETC affect the video quality?

ETC, or Extended Tele Converter, is an interesting feature with the Panasonic GH2. I've previously looked at how it can be used to get closer video recording of the moon using the Lumix G 45-200mm lens.

Essentially, ETC is a digital zoom for video. During normal video recording, the entire sensor area is scaled down to 1920x1080 pixels. When enabling ETC, the camera crops the 1920x1080 pixels from the centre of the sensor. This achieves full HD resolution, as well as a digital zoom. See the illustration:

Since 2800/1080 = 2.6, the ETC mode gives a tele conversion effect of 2.6x. If you use the 720p video mode, the conversion effect becomes larger still, 2800/720 = 3.9.

A question that remains is to see if the video quality is still good using the crop mode. In theory, it could be somewhat worse, since the camera doesn't have the option of scaling down from a larger number of pixels.

On the other hand, we know that the camera doesn't actually sample all the 16MP of sensor pixels for each frame in the video.  That would require too much bandwidth and processing power.  Just how many are sampled is unknown, but given that the electronic shutter 40fps continous mode has 4MP, one can guess that about that many are sampled during video recording.  This is, of course, just speculation.

To study this, I have used the kit zoom lens, Lumix G 14-42mm f/3.5-5.6. Since it has a zoom ratio of 3x, using ETC in the short end should give the same field of view as the longer end without ETC. This is a good basis for comparing the video with and without ETC.

I used 40mm without ETC, and 15mm with ETC. Since 15mm times 2.6 is approximately 40mm, these two modes give about the same field of view. I recorded video using ISO 160, 640 and 2500. Here are the recordings in sequence:



To better evaluate the quality differences, I have compared still images from the video streams (click for a larger version):

It appears that the video stream recorded using ETC has worse image quality than the normal stream, at all ISO values. There is some lack of sharpness and contrast, and more noise in the ETC video streams.

The reasons for these differences could be the sampling from a higher number of pixels when not using the ETC mode, as discussed above. Or it could also be related to the lens sharpness, see the discussion in the Appendix, below.

This does not mean the the ETC videos are useless, far from it. But it is fair to say that there is some image degradation when using ETC. As a rule of thumb, I think you should avoid using ISO higher than 640 when using ETC.

ETC is still a very good tool to use when you need extra reach during video recording. If you don't have any longer lenses, ETC is the only way to get quality videos at longer reach.

Appendix, some technical aspects

I used the new 1080p, 24fps cinema mode. This is the video mode on the Panasonic GH2 which gives the highest bitrate. It is generally recommended to use this 24ftp progressive mode, except when you have significant movement in the picture frame. When there is movement, people generally recommend to use the 60fps (NTSC) or 50fps (PAL) modes.

When the lens was set to 15mm, I stopped down the aperture to f/4. In ETC mode, the camera only uses the centre of the image, where lenses are generally very sharp. I've previously looked at the sharpness of the Lumix G 14-42mm kit lens, and found it to be good wide open at 14mm. So I don't think the centre sharpness at 15mm f/4 is a significant limiting factor when using the ETC mode.

But there is probably some impact on the sharpness due to the lens performance when using ETC. Remember that the ETC mode is more demanding on the lens sharpness, since there is no downscaling. When video recording without ETC, the image is downscaled from a larger sensor area, and the lens doesn't need to be tack sharp. It is like putting the lens designed for a 16MP sensor on a 2MP sensor camera.  It's not very likely that you can identify a lack of sharpness with a 2MP sensor.

In real life use, it is of course silly to use ETC in the short end of the Lumix G 14-42mm f/3.5-5.6 kit zoom. It is better to just zoom in. But I did this to get comparable images with and without ETC.

It is much more relevant to use ETC with the longer end of the Lumix G 45-200mm tele zoom lens. However, many have concluded that it is not very sharp in the longer end, so it may not be sharp enough to get a good video quality with ETC. You may want to stop down the aperture to f/6.3 or f/7.1 for the best result.

Comparison: GH1 and GH2

When I first got the Panasonic GH1, I noted down some improvement areas for the camera. While it was a good camera, there where many areas where I felt it could be improved. Upon getting the GH2, I am happy to note that many the items have been ticked off.

Panasonic GH1 (left) and GH2 (right)

Some of the items I wrote down were very unrealistic, like implementing in body image stabilization. Panasonic have chosen their strategy, to implement image stabilization in some lenses only, not in the camera bodies. So this is not going to happen.

But a lot of other areas have improved. Here are some examples from my list:

• The control wheel has been moved to the rear side, which I prefer.
• The built in flash has become taller (as can be seen in the images below), meaning that the premium kit lens Lumix G HD 14-140mm casts a smaller shadow when using the flash.
• The new camera does feature a simplified focus scale in the display when focusing manually with a Micro Four Thirds lens. This is not an absolute focus scale with measurements, but it tells you if you are moving towards the close or far end of the focus scale, for example.
• The camera can autofocus with more Four Thirds lenses. For example the Olympus Four Thirds 50mm f/2 1:2 macro. However, the focus is slow for some of these lenses.
• When using legacy lenses, you can access the magnified focus assist view by pressing the rear control wheel. On the GH1, you needed to press two keys to get this mode: First the left arrow key, followed by the down arrow key.

There are also some development areas that remain. For example, the buffer clearing speed is very slow when recording both JPEG and RAW images.


Physical appearance

The basic shape remains very similar. The shell has been made from a different plastic material with a "crinkle" appearance. While the majority of the GH1 body was covered with a rubber-like covering, the shell of the GH2 is more slippery.

On the other hand, the GH2 gains a more solid rubber grip. Somehow, I find that the rubber-like surface of the GH1 feels safe to operate: The camera is less likely to slip out of your hands. On the other hand, the GH2 has a better grip area for the right hand.

Some people have reported that early versions of the G1 had the rubber surface peeling off. This caused negative publicity for Panasonic, and may be the reason why they have chosen a plastic surface without the rubber coating for the GH2.

On the rear side, we can note some changes. The GH2 (left) has a more pronounced frame around the LCD, which I suppose is good for protection. The red video record button had to be moved to the top-side, since the space it previously occupied is now taken up by the thumb wheel.

A subtle, but good change, is that the display button has become flatter. On the GH1, it was easily pressed by a mistake, and now this is not a problem anymore.

From the side, we can see that the SD card compartment has been moved a bit inwards into the camera. My speculation is that this was needed to fit the extended processing power in the GH2 camera.

This placement makes the card a bit more awkward to extract: There is little space for your finger between the card and the compartment door.

As a consequence of the new SD card placement, perhaps, the battery needs to be slimmer. The GH2 battery (DMW-BLC12, left) is new, which has angered some fans. This means that you can not reuse your extra GH1 battery (DMW-BLB13) for the GH2.

In this view, we also see that the tripod mount has shifted backwards.

In this side view, we see that the new flash is taller, which is very good news. Ideally, the built in flash should be as far from the lens as possible, when extended.

Video quality

The GH1 was marketed as a hybrid stills and video camera, the first in it's class to have continuous AF during video recording. In the mean time, some competitors have launched their systems. So to regain the throne as the best video enabled system camera, the GH2 must excel in video quality.

My experiments so far indicate that the GH2 does indeed provide better video quality. I devised a simple test to compare the GH1 (hacked) with the GH2 in otherwise identical settings.

What I found was that the white balance and saturation of the GH2 is more pleasing, and also that the sharpness of the video is probably a tad bit better. But in my opinion, there was not a dramatic difference.

The GH2 features a much appreciated ETC (Extended Tele Conversion). This is essentially a digital zoom that works during video recording. So your lenses become 2.6 times longer, and you can still record at full HD 1080 resolution.

I've also checked the rolling shutter properties of the two cameras. I found that they were mostly identical in this respect. The GH2 might be slightly better.

Anyway, rolling shutter artifacts is not a huge problem with the GH1 and GH2 cameras. Unless you deliberately generate the artifacts, you're very unlikely to find this being a problem. This is in contrast to the Samsung NX10, which I found had significant rolling shutter artifacts.

Autofocus speed

While I had no problems with the autofocus speed of the GH1, I am still happy to see that they have further improved with the GH2.

I'm especially happy that the autofocus has improved when using the Lumix 20mm f/1.7 pancake lens, which felt a bit sluggish on the GH1. Here is a summary of my AF speed readings.

The GH2 appears to be better at continuous autofocus too, according to my test.

Taller built in flash

As mentioned above, the GH2 has a taller built in flash. In theory, this should be good for several reasons: Keeping the built in flash as far away from the lens as possible is generally a good idea. It makes the lightning more flattering when photographing people.

Also, it is a known fact that the GH1 built in flash casts shadow when using the premium kit lens Lumix G HD 14-140mm. Here's how the shadow looks using GH2 (left), and GH1, both at 14mm and having the lens hood attached.

GH2	GH1

As you can see, the GH2 flash reduces the shadow cast a tiny bit, but the difference is rather subtle. On the other hand, you would probably not use the flash at 14mm focal length and 1 meter distance very often. And increasing either will reduce this problem. So for real life use, this is not that much of an issue.

Mirrorless cameras, like the GH1 and GH2, typically require a pre-flash to measure the intensity of the flash. This takes some more time than with DSLRs, since mirrorless cameras don't have a light sensor. They use the imaging sensor as a light sensor.


Battery life

Compared with most DSLR cameras, the battery life of the GH2 is not very impressive.  This is due to operating in live-view all the time.  DSLR cameras don't need the LCD for viewing during SLR mode, and save power that way.

With freshly charged battery, I found that I could record 144 minutes of video before needing a recharge.  This was with the LCD display on all the time. Using the EVF rather than the LCD probably gives better battery life.

It is possible to buy third party batteries for around US$20, but they give some reduced functionality.