The newest sibling in an interesting family.
I've had my nose in family matters for the last few weeks and I nearly missed the exciting news from my current favorite camera company, Panasonic. They've been busy lately churning out very desirable cameras and they've just announced one that most photographers will snub while their friends across the hall in video might just adore. It's labeled as the GH5S and, much like Sony's line extension of the A7 series into an A7S and A7Sii, it's the low light version of their previous flagship hybrid camera, the GH5. While you can do a lot of great engineering in order to make a camera that is a good compromise between still photography and video there are some advantages in presenting a camera with a sensor that is optimized for one or the other. And that improved video segment is what the GH5S is directly aimed. But while its specialization for video files seems to disqualify it as the top choice for a stills camera I still find it fascinating. I'll try to explain why...
First, a few important specifications and non-features of the GH5S: It is effectively a 10 megapixel, m4:3 format camera. In the age of 50 megapixel behemoths it would seem that this spec alone disqualifies it from anyone's consideration but you have to remember that whether you have a 24 or 50 megapixel camera you still only get 8 megapixels of resolution with which to work in your 4K video files. All the rest of the information is tossed away when your camera downsamples the images. You might also remember that the reason high megapixel count cameras can do good "low noise" is that they don't need to have their files enlarged to the same degree as lower megapixel cameras. But the lower number of pixels usable for video means you end up with much smaller pixels which, individually, are prone to higher noise and lower dynamic range. The high megapixel cameras only deliver their "secret sauce" when all the millions of pixels are aggregated together into working files.
A camera with many fewer pixels, such as the GH5S or the ASony A7Sii, have the advantage of using the full sensor area to host much bigger pixels. That means each pixel can absorb more light energy and has much more native dynamic range. Another advantage is in perceptible edge acutance. That makes lower pixel count cameras appear sharper up to the resolution limitations of the viewing medium. In Kirk Theory this means that prints and digital images up to the limits of the display resolution should look sharper; more defined. More image like. But the advantage most people will point to in the lower pixel count tech is the extremely clean and saturated ISO performance.
One of the early Nikon DSLR cameras I owned was a D2H. It was a 4 megapixel, APS-C camera that Nikon introduced, alongside the D1X, in order to have a sports camera that was capable of faster image processing and buffering. While counterintuitive I pressed the camera into service on one shoot to make a cover portrait for an IBM magazine. The file was perfect. The full sized, 9x12 inch color cover was indistinguishable from the medium format film versions I'd shot previously. Around the same time there was a famous wedding photographer named Denis Reggie who was working for serious fees with several of the EOS-1D cameras which at the time were also 4 megapixel cameras. His work certainly was not considered inferior in the new digital renditions to his previous work using Hasselblad cameras. As long as he and I used our cameras in the correct and optimum zone of parameters they were able to deliver impeccable results. The larger pixels had a look that we traded away as we bought into the massive megapixel trend. Now when we blow up files to 100% we see a sea of mush which is explained? away by the dictum that we not look at files at 100%. It was a different world with the older, lower res cameras. You could go to 100% and the files were still convincing.
The other thing that will doom the GH5S among stills-only practitioners will be the elimination of in-body image stabilization. You can get your stabilization from your lenses or do without. A serious setback to those hoping to keep those kitty whiskers tack sharp when photographing after that third cup of espresso....
So, why the heck would Panasonic perfect their IBIS in the GH5 and the G9 and then drop it altogether in the new camera? I've heard two versions and I think the second one is the most plausible. The first explanation is that since the sensor is one of the multi-aspect ratio type that they've used in the past the total size of the chip was too big. I'm not buying this. The second explanation is that the vast majority of working videographers at whom this camera is aimed are more apt to use third party gimbals and SteadiCam devices rather than relying on the limitations of moving sensor tech (which does have certain limits for video). Panasonic may feel that having the chip positively locked down would be much more reliable when using external devices to achieve smooth results. That would be hard to physically do with a floating sensor. I'll buy this explanation because it makes sense that they would believe this compromise would better suit their market.
So, now we have three cameras sitting at or near the top of the Panasonic product line, concurrently. We have the GH5 which represents that most capable all-rounder. It's the right blend of technology for the user who wants to buy and use one model exclusively. Just because the GH5S arrived to deliver better high ISO files doesn't mean that the GH5 becomes obsolete. It's still more capable when it comes to delivering both high res stills AND great, 4K video. In fact, its video file capability and rich feature set makes it the best all purpose hybrid camera in the Panasonic Pantheon.
The GH5S is more specialized. It delivers great video in low light. It's got less to read off the sensor so it will most likely have less rolling shutter. And, for web only still imaging the same low light attributes that make it a perfect adjunct to a system that already contains a GH5 would also make it a wonderful (though resolution limited) low light camera. I'm not in the target market (yet) and probably won't line up to buy one out of the gate but I hardly think Panasonic has misstepped or misjudged. I think there is strong demand in video circles for a camera like this one. The high ISO capabilities are valued and the look of test files I've seen is very positive. The 240 fps slow motion is almost miraculous.
From a still photography point of view I am interesting in how the files might look. There is an aesthetic difference in high density and low density sensors and while the high density sensors fare better in certain enlargement sizes I think there is the distinct possibility that many will like the more elusive attributes of the lower density sensors better; when used at certain sizes. I'll want to get a test camera to see just how different the files seem to me.... If the color and tonality are beautiful, and the new Raw files are really 14 bit, it might just be a perfect head and shoulders camera. I know it will be an effective social media tool.
And that leaves me pondering the G9. On paper it's not as tricked out for video as the GH5 but on paper and on screen seem to always be two separate issues. The consensus of early reviewers is that this camera (G9) is better optimized for stills, and action. What I really suspect the first part of that statement means is that Panasonic has tweaked the Jpeg file output to provide a lower noise profile and more exacting and pleasant Jpeg sharpening. Something I'm sure Jpeg shooters will appreciate and fast moving journalists will make good use of. That super power becomes hazier in value if you are the kind of shooter who embraces RAW shooting and RAW processing.
I have a suspicion that underneath the top layer of image processing the RAW information is very, very similar as might be the construction and technological generation of both sensors. This suggests that shooting RAW files delivers a nearly identical soup of information with which to work. Pulling the RAW info into Lightroom, PhotoShop or Capture One will probably mean that a file from one file can be processed to match files from the other camera without much effort. Getting the G9 might mean better out of camera Jpegs but with a bit of work in RAW conversion the differences will be moot.
So, where does that leave the buyer? I think that you need to contemplate your historic and future use of cameras. If you are a careful studio worker and shoot in optimum conditions either of the two higher resolution cameras will work for you. I can see choosing the G9 for still life work if you desire the high resolution mode (similar to the high-res mode in the Olympus cameras). If you are a video control freak who also lights his or her work you'll still gravitate to the GH5 as your first choice. The availability of all the cool codecs; like All-I, is hard to pass up.
If you have no interest whatsoever in videography then it seems the G9 would be the first choice. It offers all the resolution of the previous flagship and will probably deliver better Jpegs, more still life resolution, faster sports performance, enhanced focusing and a bigger buffer. It scrimps on the video codecs; otherwise there would be no reason to choose a GH5....
On the off chance that you are video only and have no interest whatsoever in shooting large production still images then the GH5S might be a good choice for you; again, with the caveat about codecs and ultra-rich video files.
The delightful thing about the current Panasonic system is that they have offered us a rich choice of tools which can be used singly or interchangeably. I'm happy with my two GH5 cameras but am reasonably certain that the first time I can constrained to shooting multi-day job under dim lighting I'll be whipping out that Amex card and adding the "S" to the mix.
The G9 might be a harder sell for me since I am usually a Raw shooter and have come to love the look I'm getting with the All-I, 200 mbs files in 1080p from the GH5. But the bottom line is that we are being offered the flexibility to mix and match to best suit each of our own shooting situations without compromise. Of course, when I get the winning lottery ticket I'll just buy two of each and wait happily for the next versions.
GH5, GH5S, G9. A very powerful and interesting portfolio of imaging tools.