Very exciting if true – Panasonic GH5 sounds like a bomb – including 6K from 20MP sensor – but something does not add up!

Panasonic GH5 - 6K?

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An image to rival RED Dragon 6K for less than $2000? Yes please.

43rumors have given their highest rating to the following information. Please take this as a rumour until the actual announcement. Something does not make sense about the sensor resolution.

Although my current favourite camera for stills is the Canon 1D C, for video I have been using a raft of different cameras and to be honest I’m not 100% happy with any of them. It looks like we may finally get the small cinema camera of our dreams if these leaked specs for the GH5 are correct.

Here are the rumoured headline specs for the Panasonic GH5 –

20 megapixel sensor with 6K output (RED Dragon is also approx. 20 megapixel for 6K).
6K mode 24,25,30p.
4K mode is oversampled from 6K and 4:2:2 10bit.
No extra sensor crop in video mode (makes possible 1.28x crop with full frame lenses on Speed Booster XL).
4K photo bursts at 60fps (no info on maximum 4K video frame rate yet but does imply 4K 60p could be present!).
1 stop better high ISO performance.
Downscaling 6K to 1080p will likely give you another 2 stops better low light performance so expect ISO 12,800 to be perfectly usable.

So to sum that up in one sentence –

A 6K mirrorless camera, effective 1.28x crop, usable up to ISO 12,800 in low light and of course lovely 10bit 4:2:2 for green screen and FX work.

Compare this to the current best image on a DSLR, the 1D C which is 4K, effective 1.3x crop, usable up to ISO 12,800 but only 8bit 4:2:2 MJPEG codec with large file sizes, then throw out the ergonomic challenges of the DSLR form factor and replace with a mirrorless body, even smaller and lighter yet with a ton of video shooting aids, built in EVF, super-adaptable lens mount and you have a winner.

Cooke vs Sigma

However I have noticed that something does not add up about the resolution numbers quoted in the rumoured specs –

The last 20 megapixel Micro Four Thirds sensor we saw came in the Panasonic GX8.

Micro Four Thirds sensors are usually 4:3 aspect ratio, so this chip had a horizontal resolution 5184 pixels wide.

The resolution of DCI 6K cinema is 6144 x 3240. As you can see, there’s a gap. A 20MP Micro Four Thirds sensor would be capable of 5K, not 6K.

One possibility is that Panasonic have decided to make a multi-aspect ratio sensor, as last seen in the Panasonic GH2.

16:9 or even DCI 6K would use the full width of the sensor, getting it closer to 6K. Meanwhile 4:3 stills would use the full height. The entire sensor would have to be between 24-28MP in total but that would never be used in total, it would be there to facilitate the multiple aspect ratios whilst maintaining the same diagonal field of view from the lens. That might explain why the leaked specs quote a 5K (20 megapixel) sensor in terms of 4:3 stills. But how much wider would the sensor have to be to accommodate 6K?

On the GH2, the 4:3 stills were 4608 pixels wide but in 16:9 the sensor measured 4976 pixels wide, an increase of 8% in horizontal resolution.

Apply the same increase to the 5184 pixel wide 20 megapixel 4:3 stills and we have 16:9 on the GH5 coming out at 5598 pixels, so 5.6K. If Panasonic have pushed this to accommodate an even wider DCI aspect ratio that might explain how they get to 6K.

However – they’d have to make the sensor 12% wider than a standard 4:3 chip to reach 5.8K – the minimum I’d consider worth calling “6K”, which begs the question: would their native lenses cover that area? Especially with the added sensor shift of 5 axis IBIS? Perhaps the multi-aspect ratio sensor could actually assist IBIS by giving it a larger margin but only in 4K mode?

Regardless of the exact 6K capabilities (if they exist at all), if indeed most of this turns out to be correct it is very exciting indeed and shows why we have had to wait longer than normal for the GH4’s successor. Obviously this technology would be a hugely complicated R&D job to fully realise at the factory as well – which could explain why the GH5 is rumoured to miss Photokina and come late in the year, perhaps even in early 2017. Worth the wait? Absolutely.

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