The rumor has been floating around for a few days, but new information appears to confirm that Panasonic is about to announce a low light variant of the GH5 camera on December 15. This new camera, potentially called GH5s, would feature a lower resolution sensor in order to improve the low light performance. Here is what we know.

The Information and Source

The rumor surfaced a few days ago on 43rumors.com and more information has emerged today. According to the rumor website:

This is a low light version of the GH5. It probably has a new low resolution sensor.

This will be a more advanced version of the GH5 with improved video quality, stunning low light performance

higher price tag than the GH5.

Same GH5 body

December 15 (+ or – 1 day)

The website also released a blurred image of the new GH5 saying that “The GH5s on the back looks exactly the same as the GH5 body with one exception: It has the “red ring” on the drive wheel like the one used by the new Panasonic G9”

I was able to enhance the leaked image with the CSI software. The new GH5 seems surprisingly sleek and user friendly.

What Can We Expect?

First, this is a rumor and nothing has been officially confirmed by Panasonic at this point. However, rumors tend to be quite accurate before the announcement deadline and mid-December is in two weeks. As the deadline approaches, more people are getting involved in the launch which increases the chances of a press leak. For instance, Panasonic would have to spread the news internally beyond the usual small circle of program managers. Thus, the information is harder to control. The organization of this type of event requires sharing information with external entities such as marketing and communications agencies. The fact that the rumor website presents an image of the camera tends to confirm this.

Specifications

In terms of specifications, it makes sense for Panasonic to re-use as many parts as possible from the original GH5. The commonality between the two versions allows to generate economies of scale and assemble the new camera from the same production line.

It’s no secret that small Micro Four Thirds (MFT) sensors are not good to catch photons due to their small size and high pixel density. For instance, the full frame sensors found in Sony a7 and Canon 5D cameras are about four times bigger than the GH5 sensor.

Personally, I have no problem using ISO 3200 or 6400 on my full frame cameras but I rarely venture beyond ISO 1000 on my GH5, especially in video mode because the noise becomes prominent after that.

There are not too many options to improve the low light performance of a given sensor:

Enhance the signal treatment with complex algorithms and more processing power (new processor). Each manufacturer does that between two generations of cameras but the gains are limited.

New sensor technology like the backside illumination (BSI)

Lower the pixel density by reducing the resolution. Each pixel is larger and catches light more efficiently (better SNS).

Panasonic will probably use a combination of these three options but lowering the pixel density is probably the most effective solution. Sony took this road with the a7S camera that stacked only 12 mpx on a full frame sensor to achieve exceptional low light sensitivity.

Thanks to its large pixel size, the Sony a7S delivers usable images at ultra high ISO. On the other end, the Nikon D850 achieve solid results despite its high resolution sensor. Pixel size, sensor technology and image processing contribute to the low light performance.

The main question is to know which sensor is going to make its way to this new “GH5s.” Due to the GH background, we can assume that this camera is primarily designed for the video market. As such, the sensor must be at least 9 mpx to produce Cinema 4K image (4096 x 2160 = 8.85 mpx). Because the sensor is using the 4 by 3 ratio, the resolution should reach a minimum of 4096 x 3072 or 12.6 mpx to ensure proper 4K DCI (or 11 mpx for regular 4K UHD) unless Panasonic decides to introduce a new aspect ratio sensor. In any case, the final resolution should reach 10 to 12 mpx.

If we look at the pixel pitch:

As you can see, the pixel pitch of the new GH5 would place it at the level of the Nikon D850 or Canon 5Ds and above most current APS-C cameras on the market.

A lower resolution sensor would also facilitate the task for the processor. Right now, the GH5 image processor has to handle 20 mpx before down-scaling it to 4K resolution in 60 fps (8 bits) or 30 fps (10 bits). Slashing the resolution and eliminating the down conversion step opens the door to additional features such as a higher frame rate (4K 120fps?) and better rolling shutter. This new camera could also provide additional codec support (ProRes, Cineform, 12 bits or raw output?). Finally, we should see some benefit on the dynamic range (HDR video?).

What About the EVA1 and Current GH5 Users?

Even though Panasonic is not known to hold the specs like Canon does, the company just released its professional EVA1 S35 camera this year. Would it make sense to announce a killer GH5 right after the EVA1 hits the shelves?

Finally, what about the current GH5 users? The GH5 is only nine months old, deliveries began late March 2017. Personally, I would be very upset if this rumor is true after spending $2,000 on the original camera. Unfortunately, this would not be the first time in history that manufacturers announce new products just a few months after the first generation. Sony announced the A6500 not even a year after the A6300 release, the a7SII and a7RII were very close to the previous model. DJI also did it with the Phantom 4 Pro against the Phantom 4… If you ask me, that’s a bad move. On the other hand, MFT photographers might find plenty of discounted GH5 on eBay and Craigslist soon…

Stay tuned, we'll know what's coming or not in a few weeks.

Update: You can buy the GH5 for 25% off right now.

[via 43rumors.com and mirrorlessrumors.com]