Panasonic GH5: the Sensor has to be Multi-Aspect!

That’s the most logical conclusion I got so far

15 min readOct 11, 2016

I already covered a whole lot about the sensor possibilities, but while I was discussing and explaining why I think it could be a multi-aspect sensor, I actually came to the realization of some missing pieces that fit this idea almost too well.

The key for the whole speculation is still the Photo 6K announced by Panasonic because it’s the most intriguing one and it’s kind of odd in several ways.

But before that, let’s just understand what “true” Photo 6K would really mean, so we have a better understanding of what we can or could expect.

What’s Photo 4K?

It’s basically 3840 x 2160 pixels, 8.3MP still grabs from 4K video in 16:9 aspect ratio at 30 fps burst. Ultra HD is 4x the resolution of a Full HD video.

Then, what should Photo 6K be like?

Following that logic, it should be 5760 x 3240 pixels, 18.7MP still grabs from 6K video in 16:9 aspect ratio at 30 fps burst. This is 9x the resolution of a Full HD video.

You don’t have to use 16:9 but that’s clearly the base of the concept.

Panasonic’s press release says:

In the LUMIX GH5, the conventional ‘4K PHOTO’ function is dramatically advanced to form ‘6K PHOTO’* which lets the user cut a still image out of ultra high-quality 18-megapixel video with approx. 9 times the pixel count than Full-HD.
Taking advantage of its high-speed, long-time burst shooting capability, spur-of-the-moment shots can be saved in beautiful photos with higher resolution that complies with larger-sized printing by substantially increasing the resolution from approx.8-megapixel (4K PHOTO) to approx.18-megapixel (6K PHOTO*) Furthermore, approx.8-megapixel 4K PHOTO can be captured at 60 fps.
*“6K PHOTO” is a high speed burst shooting function that cuts a still image out of a 4:3 or 3:2 video footage with 18-megapixel (Approx.6000 x 3000 effective pixel count) that 6K image manages. The name ‘6K PHOTO’ is tentative.

So let’s break it down, it’s just a few words but they do contain a lot of hints if you can pick them up.

We can start by the fact that Photo 6K is a high-speed, long-time burst shooting capability that take 18MP stills that comes from a video feed approximately 9x the pixel count of Full HD.

Which made me conclude in a previous article that since this is a full sensor readout feature, 4K should come without extra cropping — like the GH4’s 2.2x crop in 4K.

So let’s start with this piece of information:

18-megapixel (Approx.6000 x 3000 effective pixel count)

Well, this is 2:1 aspect ratio, which I find weird because Photo 4K doesn’t even offer a 2:1 option and by not mentioning the other aspect ratios — mainly 4:3 — I will assume that either they won’t be available or simply that the 2:1 exemplifies better the name Photo 6K. Either one is possible, but 2:1 is probably just a generic way to say it can be 16:9 or another similar video aspect ratio without getting too specific about it.

So I found some cameras that claim to shoot 6K, the RED cameras use 6144 x 3160 pixels and the KineMAX has 5760×3240 pixels. The RED follows the DCI standard, if DCI 2K is 2048 pixels wide, then 6K is 3x more (6144 pixels) while KineMAX follows the TV standard of 16:9, if HD is 1920 pixels wide, the 6K version of it is 3x more (5760 pixels).

So although it doesn’t seem to have a formal standard, Panasonic could choose either one of the two or something in between, since both options are “approximately 6000 pixels”.

Another interesting but quite mysterious piece is this one:

cuts a still image out of a 4:3 or 3:2 video footage

Why does Panasonic say “4:3 or 3:2” video?

That doesn’t make sense! This is clearly about full sensor readout but isn’t Micro4/3 a 4:3 sensor?

Why is Panasonic mentioning 3:2 aspect ratio at all? In which normal situation could the video feed possibly come from a 3:2 portion of the sensor?

How would multi-aspect sensor work?

If you want further explanation just read this article, in which I try to explain step by step, but here I will go direct to the point.

What multi-aspect ratio sensor would Panasonic use? Something similar to the GH1 and GH2?

Similar, yes but it might not be the same.

Why?

Because now there is DCI 4K (19:10), which has a different aspect ratio than Ultra HD (16:9), since Panasonic is already using DCI 4K, being the widest at 4096 x 2160 compared to 3840 x 2160 of Ultra HD, DCI 4K would be more interesting as a priority when it comes to designing a multi-aspect ratio sensor than 16:9.

What’s the difference then?

The main difference is the crop factor. As I already talked about, crop factor can be rather confusing since people measure it in different ways in different situations. A lot of people measure crop factor using the diagonal of the area when the most precise measurement is the Field of View and Angle of View.

Otherwise, if the GH1 and GH2 multi-aspect sensor has the same diagonal of the Micro4/3 sensor, it would be called a 2.0x crop and not 1.86x crop. More importantly, when you crop a 16:9 image out of either 4:3 sensor or 3:2 sensor, like it happens in most camera when they shoot video, if you were to use the diagonal as your crop factor parameter, there would always be an extra crop factor since the diagonal of the 16:9 would be different. But if you measure based on FOV/AOV, it stays the same and you never see people talking about how video always has a crop factor.

So, as we already know, if it’s a multi-aspect sensor based on 16:9 aspect ratio as its widest crop, you will get around 1.86x crop factor but how about when it’s based on DCI 19:10? You will get slightly less, so you will end up with something around 1.8x crop factor.

These crop factors are calculated based on the original Micro4/3 crop factor of 2.0x, but I can’t be quite exact about the 1.8x crop factor because there are far too many possible variations and I don’t know which exact combination Panasonic will use. So it might not be exact 1.8x but it’s something around that.

And let’s not get too technical because Canon APS-C is not exactly 1.6x and neither Nikon is exactly 1.5x like we usually say. Actually, within Nikon’s own cameras there is a slightly variation between 1.52x and 1.55x, so let’s not give this too much attention and end up missing the point here.

Anyway, there are three interesting scenarios for a multi-aspect ratio sensor that has a DCI 4K aspect ratio within the Micro4/3 image circle:

The Micro4/3 portion of it will have 20MP, just like the E-M1 and the full sensor would at least match the width of the KineMAX with 5760 pixels for a bit more than 22MP
A sensor in which the horizontal pixels match the one used by RED with 6144 pixels, resulting in about 6144 x 4115 pixels sensor with 25MP total and 22.5MP for the Micro4/3 portion of the sensor
Something in between these two options but still close to 6000 x 4000 pixels sensor

Yes, a multi-aspect sensor with DCI 4K 19:10 aspect ratio within the same Micro4/3 image circle is basically a 3:2 sensor! Very curious, huh?

Between these options, I think that there are more chances of Panasonic adopting the one that has 20MP for the 4:3 area of the sensor because of the following reasons:

Some rumors back in March and also another one a couple of weeks before the Photokina 2016 development announcement did specify that the GH5 would have a 20MP sensor
There were also a rumor saying that the GH5 would have a multi-aspect sensor
Despite having more than 16MP for the total multi-aspect sensor, the Panasonic GH2 was still called as a 16MP sensor camera, so calling the GH5 a 20MP camera despite having more than 22MP makes sense since the Micro4/3 area of the sensor will have 20MP
If Panasonic and Olympus did share the sensor technology development, both being 20MP would make sense
By having the exact same pixel size, you can use the same micro lenses, color filter array, sensor wafer base and some other components, so you can cut production cost
This “20MP sensor” would easily match the KineMAX’s 6K of 5760 horizontal pixels at it’s full width, so technically still a “6K sensor”

Of course the other options are still a possibility, but they are just less likely than a 5760 pixels one. As I said, saying “Approx.6000 x 3000 effective pixel count” leaves it open to interpretation, so anything between 5760 pixels or 6144 pixels is possible.

But let’s get back to this part again:

cuts a still image out of a 4:3 or 3:2 video footage

Well, now we know, a multi-aspect sensor based on DCI aspect ratio would be exactly that, a 3:2 sensor! Even a multi-aspect sensor based on 16:9 is still pretty close to 3:2.

But then, why did Panasonic say “4:3 or 3:2” and not just “3:2”?

Again there are two possibilities:

Panasonic is also testing a 4:3 sensor with 5760~6144 pixels in width
Panasonic didn’t want to confirm it’s really a multi-aspect sensor

What are the odds of a 24 to 28MP Micro4/3 sensor? I’ll tell you, very small. The most logical conclusion would be that it’s indeed a multi-aspect sensor.

Also if Panasonic was to just say it “cuts a still image out of a 3:2 video footage with 18-megapixel” that would immediately raise some eyebrows and people would start asking why 3:2 and not 4:3?

And it’s clear that Panasonic didn’t want to give up any more information than the 4 new features they talked about in their presentation:

10-bit 4:2:2 Internal Recording
4K at 60fps
Photo 6K burst at 30 fps
Photo 4K burst at 60fps

Even if the multi-aspect sensor is not based on DCI aspect ratio but 16:9 like the GH1 and GH2, you can still get “Photo 6K”. The choice between DCI aspect ratio or 16:9 only depends of how Panasonic will make it work, because each choice will need some workaround.

Ideally DCI 4K will have a wider FOV when compared to Ultra HD and at the same time you would want to do Photo 6K at 5760 x 3240 pixels and even downsample it to Ultra HD when outputting video. But that would mean a 6144 pixels sensor and I don’t think Panasonic will go for that. And it’s not like there is such a huge difference between choosing one or another anyway.

In theory, if Panasonic can do “Photo 6K” at 30fps, they should be able to make a video out of it and the fact that Panasonic didn’t say 6K video can mean a few things:

Photo 6K is a 30 fps burst that is not sustainable to work as a video feat but it shouldn’t be just a few seconds since Panasonic mentioned “long-time burst shooting capability”
Panasonic is undecided or will only reveal it at the GH5 full announcement
Panasonic is protecting their higher-end video and cinema cameras

Without any other camera capable of 6K video, Panasonic could be simply protecting their Video and Cinema cameras. Or maybe Varicam division would be a bit upset with the Lumix division if they were to jump ahead of Panasonic’s high-end Cinema camera in the 6K department. I’m not sure about that and that’s not really important right now, but the first option seems the most plausible one.

Sensor Technology

I want to assume that the GH5 has a very similar sensor technology as the E-M1 MK II and that this sensor is also capable of 60fps but Panasonic decided for a long-time burst shooting capability of 30 fps at a slightly less resolution instead of a 20MP 60fps RAW burst for just a few seconds like Olympus chose for the E-M1 MK II. Very similar features but with some philosophical differences.

Hmmm… Maybe this was all part of the deal between Panasonic and Olympus.

Panasonic:

10-bit 4:2:2 internal recording
4K 60fps and Photo 4K 60fps
6K Photo 30 fps burst
no RAW output from photo burst

Olympus:

No 10-bit 4:2:2 internal recording
No 4K 60fps
20MP Full Sensor readout 60fps
RAW photo burst

Thinking a bit more about it— maybe a bit too much —, I think that the rules are actually much simpler:

Panasonic:

10-bit 4:2:2 internal recording and 4K 60fps

Olympus

Full sensor readout RAW burst

Photo 6K is a way Panasonic found to workaround not being able to output true photos, because either Photo 4K and Photo 6K are image grabs from video and that’s how Panasonic has always advertised.

As for Olympus, they are okay with no 4K 60fps and 10-bit 4:2:2 as Panasonic probably helped them finally step up their video quality and also provide 4K while Olympus possibly helped Panasonic with IBIS.

This is just speculation from my part as I couldn’t possibly know for sure any of that but I’m trying to go with things that do make sense within this context — I find the new codec of 200mbps All-I 1080p in the E-M1 MK II quite suspicious, doesn’t that kind of hint for a Panasonic help?

In summary, Panasonic has video advantages while Olympus has photo advantages, it simply makes sense.

The Arguments Against Multi-Aspect Sensor

Not being a multi-aspect sensor makes it quite hard to accept the Photo 6K feat announced by Panasonic because you would have to assume that it will be a Micro4/3 sensor with at least 5760 x 4320 pixels and 24.9MP, up to 6144 x 4608 pixels with more than 28.3MP.

No rumor talked about a 25MP to 28MP sensor, this pixel count sounds way too high and it would mean a compromise in low light performance, one of the big knocks on Micro4/3 cameras right now and something that they are certainly trying to improve.

I should be noted that the person that shared this 20MP rumor is also the one that got all the GH5’s specs right (Photo 6K, 10-bit 4:2:2 internal recording and 4K 60fps).

He also mentions no crop in 4K — due to full sensor readout — , new and improved sensor (1-stop) and Dual Card Slot. So by him saying 20MP sensor, this should have some weight when considering the odds of this likely being true as well.

There is a slightly possibility of such high 25 to 28MP sensor if Panasonic adopts BSI technology or similar and even using copper wiring like Sony does with their latest 1" 20MP sensor.

It’s not impossible but this does start become a much harder narrative than all of the evidences that points out for a multi-aspect sensor. Just like I thought that it didn’t make sense to not have IBIS in the GH5 when all new Panasonic cameras have it — and Panasonic haven’t had any prior overheating issues like Sony does — , I think that it has to be a multi-aspect sensor.

“Photo 6K is just for Marketing, it won’t be even 6K”

Another common argument is that Panasonic is completely deceiving their customers with marketing mumble jumble. Why take such a risk when the GH5’s main feats are 10-bit 4:2:2 internal recording and 4K 60fps? Does Panasonic really need to commit to something they won’t deliver? I fail to see the logic in this.

There are people saying that Panasonic is willing to go as far as throwing away the base concept Photo 4K when coming with the Photo 6K, despite already mentioning that it will have approximately 6000 x 3000 pixels.

For me that doesn’t make sense, otherwise Panasonic could had simply said “Photo 6K is about 18MP image burst at 30fps from full sensor video” without ever mentioning 6000 x 3000 pixels at all.

If Panasonic was truly going for a 20MP Micro4/3 sensor and the whole Photo 6K was about deceiving consumers, mentioning in the press release that it’s close to 6000 pixels and 2:1 aspect ratio would be very stupid.

Panasonic has never done anything like that and it’s not even like they need to, how do people think that this bad and long shot is more likely to happen than simply choosing a multi-aspect sensor when that basically solves all of that? The multi-aspect sensor is not only part of the GH series heritage but it was born from that idea, it’s in the GH series DNA.

Old timers missed the multi-aspect sensor when the GH3 didn’t have one, it was kind of understandable that the GH4 didn’t have one because the 4K was already cropped, it wouldn’t make sense to develop a multi-aspect sensor under that circumstance anyway, but now it makes perfect sense.

Final Thoughts

I think this is as deep as you can go from such little piece of information, for me it makes almost too much sense to possibly be something else.

Well, it doesn’t look like Panasonic has finalized the GH5’s specs yet — but they are probably about to — so there can be changes, but as far as the information we have and using logical deduction, I think that’s it.

The Panasonic GH5 will have a multi-aspect sensor that covers at least 5760 pixels wide — probably a bit more to accommodate both DCI 4K and Photo 6K— and the GH5 will be a “20+MP Micro4/3 camera”

As part of the sensor will be outside of the Micro4/3 image circle area, it means that you won’t be able to use the whole sensor, so despite having more than 20MP, the maximum resolution would still be the Micro4/3 area of 20MP, therefore, this another reason why this is a 20MP camera and not a 22+MP.

For instance, with the GH2 was a 16MP camera and the 4:3 portion of the sensor had 16MP, while the 3:2 had 15MP and the 16:9 had 14MP. Same thing would happen with this possible sensor, so the total MP count is not important if the camera won’t be able to use it, so they use the maximum usable MP count, which is the Micro4/3 area of the sensor.

Although the base of Photo 6K/Photo 4K is the 16:9 images, just like the LX100 has a sensor acting like multi-aspect sensor and it takes advantage of that during Photo 4K, it means that in theory, besides the 18MP (5760 x 3420 pixels) shooting at 30fps for the Photo 6K, the GH5 should be able to shoot 20+MP at 30fps at 4:3 aspect ratio, 19MP to 20MP stills from 3:2 and 15MP image grabs from 1:1 aspect ratio.

So this might not be a 60fps RAW burst like the Olympus E-M1 MK II but this is a very interesting proposition for Photographers and not just Videographers. But the key to this feat is Panasonic’s ability to improve the tracking Auto focus.

If Panasonic can do that, be with some new technology or finally implementing Phase Detection Auto Focus, then it means that tracking AF might work during Photo 6K. So you could have a Photo 6K 30fps burst with tracking AF whereas Olympus “only” offers 18fps with C-AF.

I’m also very curious about how many RAW and/or JPEG the E-M1 MK II’s memory buffer can hold during 18fps and 60fps as well as how much time the GH5 will be able to shoot Photo 6K.

As I developed over this article, there are other possible scenarios, even using different multi-aspect sensor size or pixel count, but this seems to me to be the most likely, the one with more “coincidences”.

Once we have established that this is a multi-aspect sensor, it can be based on 16:9 like the GH1 and GH2 or it can be based on DCI 19:10 aspect ratio like I was speculating, bug either one can work.

As I said before, the difference between these options is that a DCI aspect ratio based multi-aspect sensor has 1.8x crop factor because it’s slightly wider, while a 16:9 based multi-aspect sensor has 1.86x crop factor.

In theory, all Focal Reducer adapters that already work with Micro4/3 sensor should work just fine with a multi-aspect sensor and that’s exactly the beauty of a multi-aspect sensor!

Because as I explained before, despite having different FOV, it’s still within the exact same Micro4/3 image circle. For native lenses or adapted lenses, nothing should change, otherwise, native Micro4/3 lenses wouldn’t had worked well with the GH1 and GH2.

Personally, I would like Panasonic to achieve less crop, so I would opt for the DCI based multi-aspect sensor and that’s much closer to Super 35 sensor than normal Micro4/3 sensor is. But the difference between these two options are negligible, the choice for Panasonic is down to the aspect ratio of the Photo 6K and the downsampling process of DCI 4K and Ultra HD.

This is obviously still in the realm of speculation since I have no inside info, so anything can happen, but this looks to me like the most logical and most likely scenario for the Panasonic GH5’s sensor.

As there are already some photographers out in the wild testing the Olympus E-M1 MK II, the announcement seems imminent, much more so than the Panasonic GH5. I don’t know when Olympus is going to to start shipping the E-M1 MK II but I assume that the GH5 should be announced before that, so it might still happen in 2016 — and not CES 2017 like I was speculating.

Who knows?

I’m very curious about the DCI 4K 237mbps codec from the Olympus E-M1 MK II and also if the E-M1 will output 10-bit 4:2:2 or 8-bit 4:2:2 via HDMI output, that will be very interesting and it can tell a bit more about possible deals Panasonic and Olympus may had done for the development of both cameras.

Photokina 2016: Panasonic GH5 series:

Part 1: Overheating Gate and IBIS rant!

Part 2: Codecs and AF improvements Speculation

Part 3: The Mysterious Photo 6K and Mysterious Sensor!

Part 4: Slow Motion, ProRes/HNxHR and Final Thoughts