What can we expect from the GH3?

The Panasonic GH series has comprised the premium camera models for Micro Four Thirds. The Panasonic GH1 and GH2 have had the best video quality among mirrorless cameras at the same time, and they are also considered to have the best sensor for photos. They are not intended to be volume models, but rather to sell at a premium price for those who want the best camera.

Panasonic GH1 (left) and GH2 (right)

The Panasonic GH2 was announced in September 2010. I bought it the very first day it was available in my market, which was in December 2010. Hence, this camera is starting to get old. In this article, I would like to speculate a bit about what we can expect from the GH3.



Timing of announcement

To speculate about when the GH3 will be announced, it is always useful to look back in time, and see when previous camera models were announced.

In the timeline above, the important tradeshows (PMA and Fotokina) are shown as vertical lines. We see that some camera models were announced in connection with these shows, e.g., the G1, GH1, G2 and GH2. However, after 2011, it seems that the announcements are less connected with the tradeshows. The PMA 2011 was cancelled, and the Panasonic G3 would probably have been announced at this event, if it wasn't cancelled.

Some have speculated that the Panasonic GH3 will not be announced until Fotokina 2012, in September. However, I think that is too late. Panasonic cannot have a top model which is two years old, I think. So the GH3 must be announced before September 2012, I think. The distance between the GH1 and GH2 announcements was one and a half year, hence, I think the GH3 will be announced around March 2012. (After writing this, it has since become clear that the GH3 was not announced around March 2012.  So now I am expecting an announcement at Fotokina 2012, late September.)

Features

And what can we expect from the GH3? The GH series will aim to be seen as the king of the hill in terms of mirrorless cameras. That was fairly easy for the GH1 in March 2009, since the competition did not have any cameras out. Now, however, there is a lot of competition.

Megapixels

The GH2 increased the effective megapixels from 12 to 16. Will the GH3 top this off with even more megapixels? Probably, yes. In an interview, some Panasonic staff were quoted to say that the GH2 got 16 megapixels for marketing reasons, mostly. And the market is back to a megapixel war, sadly. The Sony NEX 7, announced in August 2011, has a staggering 24 megapixels. I don't think the GH3 will top this, but it probably needs to close some of the gap to be seen as a serious competitor in the market. So I would guess the GH3 will be announced with around 20 megapixels.

If true, this is mostly bad news. I don't think many need more than 12 megapixels anyway, and increasing the megapixel count even more probably means that other aspects of the sensor cannot be optimal, e.g., noise characteristics and dynamic range.  But we see a trend towards more megapixels across many segments now.  The new Nikon D800 will have a staggering 36 MP on a full frame sensor.  The Nikon 1 system is the only good news in this respect.  They "only" give 10 MP, which is probably a sensible figure given their smaller sensor area.

Video modes

Both the GH1 and GH2 supplied full HD video modes with 1080 lines. The GH1 could only do this in interlaced mode, and the GH2 improved upon this by adding progressive modes.

The next big thing in video is 4K. Not very well defined, but 4K means that the horizontal resolution is around 4000 pixels. With the 1080p modes of the GH2, the horizontal resolution is only 1920 pixels. So 4K is a big step up from the GH2.

Personally, I don't think the new camera will provide 4K. It is simply a too big leap at this point in time. The new Nikon D4 flagship model does not provide 4K, and still has 1080p as the largest video mode. Rather, I think the GH3 will further refine the video at 1080p, and possibly add higher frames per second modes.

Autofocus

All Micro Four Thirds cameras so far have used the Contrast Detection Auto Focus (CDAF) method. This involves jogging the lens focus back and forth until the contrast is deemed high enough to assume that the focus is optimal. With the current cameras and lenses, CDAF have given fast enough autofocus for still images, even in fairly dim lightning.

This is different from DSLR cameras, which use Phase Detection Auto Focus (PDAF). PDAF is better at following moving targets, which CDAF currently does not do very well.

The Nikon 1 system combines the two focus methods, and employs a hybrid CDAF + PDAF method. In theory, this should be able to give better focus for moving subjects, and also to keep the focus better during video recording. Canon's new mirrorless system, the Canon EOS M, also mixes CDAF and PDAF.

The GH2, while currently probably still the best Micro Four Thirds camera for video, does not do moving targets very well, neither in photo or video mode. So how can the GH3 improve upon this? My guess is that the improvements will be incremental. I think that adding PDAF, like the Nikon 1 system does, is a too large step at this time. There may also be patent issues hindering Panasonic from implementing this. So my guess is that the GH3 will employ faster and better image processing to improve on the autofocus during video recording, but it will not employ any dramatic change to the focus technology.

Global shutter

All Micro Four Thirds cameras so far use a "rolling shutter". This means reading off the sensor values sequentially vertically. For still images, this is just fine, but if the subject moves during exposure, it could give some strange artifacts. We can see this as buildings "leaning" to one side if you pan horizontally during video capture, or rotating propellers warp in a strange way. I have compared the rolling shutter artifacts of the GH1 and GH2 here.

To fix this problem, Panasonic could implement the "Global Shutter". This would involve reading off all sensor values at the same time. Implementing this would mean that they could drop the mechanical shutter. It exists mostly to avoid the rolling shutter artifacts for still images. Hence, it would make the camera less noisy, less expensive to manufacture, and less prone to mechanical failure. Global Shutter would be a huge improvement to the camera.

So can Panasonic implement Global Shutter for the GH3? In an interview before the GH2 was launched, a Panasonic employee was quoted to say that Global Shutter could not be implemented until at earliest in the GH3.

My guess is that a true Global Shutter can not be expected with the GH3. But perhaps they can make the rolling shutter quicker, and avoid most of the artifacts so that dropping the mechanical shutter becomes possible.

For comparison, the Nikon J1 mirrorless only has an electronic shutter, while the Nikon V1 has a mechanical shutter which can be used at the operator's discretion. Using the electronic shutter is silent, but can yield rolling shutter artifacts. The mechanical shutter can be used for faster flash sync speeds.

Ergonomics

The GH2 improved upon the ergonomics of the GH1 quite a bit. For example, it moved the control wheel from the front to the rear, and added a focus lever on the left shoulder. I would not expect any significant changes to the ergonomics with the GH3 model. There are not many major ergonomic issues with the GH2 anyway.

Body materials

Both the GH1 and GH2 employ a plastic shell over a stainless steel frame. Currently, there is a trend towards using more metal as the shell material. For example, the recently announced Olympus OM-D E-M5 has a metal exterior, as do most of the competitor system's cameras. Personally, I think that a metal exterior for such a small camera only serves to give a "premium feeling", and not provide any real value beyond that.

So I would hope to see that the GH3 retains the plastic bodies of the predecessors. But just as the megapixel count, the body material might be important from a market perspective. Perhaps it becomes impossible to sell a plastic body camera, in which case Panasonic must change their strategy.

Weather sealing

Pro spec cameras commonly have some kind of environmental sealing, to keep out water splashes and dust. I have used my GH1 and GH2 in light rain, and not noticed any problems. But to use them in challenging environmental situations is probably not a good idea.

If Panasonic add real weather sealing to the GH3, then that is a good way to make it stand out in the crowd. That would be a step towards a more pro camera.

Other functions

The LCD display of the GH2 has 460.000 dots, which is not very impressive. The predecessor GH1 has the same LCD resolution. I think Panasonic need to up this resolution to be competitive. On the other hand, all the more recent Panasonic models have featured the same resolution, GF3, G3 and GX1. So perhaps they think it is still relevant. Using the EVF gives you better resolution, so that can be done for more critical focus control with manual lenses, for example.

The Panasonic GH2 has horribly slow buffer clearing speed when photographing RAW images. To be seen as a serious contender, I think they must improve the write speed for RAW images.

Due to the short register distance, mirrorless cameras are popular for using older SLR lenses in manual focus mode. For easier manual focusing, some have requested a "focus peaking" functionality, which would highlight parts of the image where the contrast is large, and hence, the image is in focus. If the GH3 adds this feature, then it would be easier to use with older manual focus lenses.

Conclusion

This article has been mostly speculations, of course. My guess is that the GH3 will present some evolutionary changes to the GH2, just as the GH2 did when it was announced in September 2010.

On the other hand, if the GH3 does not offer 4K video, no major improvements to autofocus during video, no global shutter, then how can Panasonic still claim that it is a premium video enabled model? It could be that they need to step up and give at least one of these features, to differentiate against the other M4/3 camera, and, not least, the competition.

Adding weather sealing could be another way to signify that this is the top model. Since Olympus has announced the OM-D E-M5 with weather sealing, Panasonic cannot claim that the GH3 is a pemium model without this feature.

Note

Since writing this article, it has become clear that the camera was not announced during spring 2012. So now, I'm expecting an announcement at the Fotokina 2012, late September.