Panasonic GH5: Codecs and AF improvements Speculation

(Part 2)

11 min readSep 27, 2016

SD Cards and Codecs

The camera showed in the picture is just a mock up, you can actually see the stickers glued to the buttons and doors but nonetheless you can get some hints from it. It seems that it has Dual Card slot but the headphone jack still seems to be in the way of the articulated screen.

The sticker in the Dual Card slot says SDXC, which means it supports up to 2TB but that doesn’t help much since any camera does that — but in some ways you can conclude that it’s not XQD card. So the speculation about the codec continues.

10-bit 4:2:2 is supported up to 4K 30 fps, which means that 4K 60 fps uses something else. I’ve seen people talking about 8-bit 4:2:2 but I couldn’t find that info anywhere, so for now I’ll assume that it’s just 8-bit 4:2:0 in 4K 60 fps — just like in the DVX200 .

The difficulty of understanding codecs is to have the parameters so you can understand what the possibilities actually are. I already covered the possible alternatives for the codec in a previous article but Panasonic basically has to choose between AVC/H.264 and HEVC/H.265 codecs and then if it will be Intra or Long GOP encoding.

Long GOP H.265 being the smallest file possible, but also the most processing intensive one. H.264 Intra codecs like XAVC-I by Sony and AVC Ultra by Panasonic output 4K 10-bit 4:2:2 files around 300mbps~500mbps for up to 4K 30p. So that’s the biggest file we can expect.

Let’s remember that the U3 cards currently supported by most 4K cameras can guarantee 240mbps (30MB/s) for video recording. There is a new Speed Class of SD cards called Video Speed Class with two classes that could be very useful, the v60, which supports 480mbps (60MB/s) and V90 with 720mbps (90MB/s).

The major issue is that there is no V60 or V90 cards out there, and as far as I know they are not selling these yet and no products uses it. That makes it less likely to be adopted by Panasonic, but it’s still possible. And if you find all of this quite confusing, I wrote a piece just to talk about the SD Cards nomenclature.

BlackMagic Video Assist 4K

The BlackMagic Video Assist 4K can record ProRes HQ and DNxHR to SDXC UHS-II U3 cards, which opens precedent for the GH5 to possibly do the same.

I just find it odd that these cards are rated as U3, which guarantees 3x slower Minimum Sequential Write Speed than a V90 card but to record such files, they actually need to be faster than a V90 card.

If these cards work fine, they have to record at least 120MB/s compared to V90 that can do at least 90MB/s. The sad and confusing thing about such new standard is that not only there doesn’t seem to exist V60 or V90 cards out there in the market but there already exists products demanding even faster bit rate.

So it’s a new standard that is yet to be adopted but it’s already outdated somehow.

At the same time if these cards are truly capable of sustaining 120MB/s, why didn’t the manufacturer advertised as such? Why lose such marketing opportunity? I don’t know, maybe BlackMagic is using some clever way to record video using some Bus Speed properties and Buffer Memory, but that looks too fancy for such low cost 4K recorder ($895).

Either way, since Black Magic Video Assist 4K already records ProRes HQ and DNxHR 4K 10-bit 4:2:2 to SD cards, Panasonic might surprise us and even go ProRes and DNxHR, but I wouldn’t count on that and neither I want such massive files — you can’t even record 10min in a 64GB card.

Of course, you also have more flavours of ProRes other than ProRes HQ and I’ve seen some tests of ProRes LT images and they seem pretty good and with a bit rate about 400mbps, that’s a better balance between data and file size, even more for an Intra codec. I’m not sure how it compares to ProRes HQ in terms of grading but a Long GOP version of it would be even smaller and keep the same quality.

I personally would like Panasonic to use U3 cards and H.265 Intra codec. HEVC codecs are the future, between Intra and Long GOP, Intra is less processing intensive but being H.265 it can still manage to have about 50% smaller file size than H.264 that fits an U3 240mbps card. Also because any card above U3 will be quite expensive and I would like to avoid having to buy a lot of expensive media and somehow get rid of the ones I already have.

But Panasonic might simply use Long GOP H.264 codec at similar compression ratio used in the GH4 for 8-bit 4:2:0 but for 10-bit 4:2:2. If overheating is really an issue, an Intra codec like ProRes is much less processing intensive, it also gives you the flexibility to choose from 150mbps (20MB/s) in ProRes Proxy until 950mbps (120MB/s) with ProRes HQ and, of course, it’s still a better solution than no IBIS.

Beyond this, there is nothing much that we actually know, it’s just good to know and get to understand what kind of card tech and codec is out there, but we can only know in future rumors and official announcement.

Speaking of announcement, if I was to guess, I think Panasonic will announce the GH5 by CES 2017.

I would prefer to be earlier but it can be even further, but CES would be a nice place to do it. Olympus said that the E-M1 MK II announcement will come later this year, so it would also be wise for Panasonic to release a few more info before E-M1 MK II start shipping or even get on pre sale.

Nick Driftwood

Nick Driftwood is working with Panasonic on the GH5. Who is Nick Driftwood? As he says in his page “Nick Driftwood AKA the GH2 Driftwood hack”, the guy that created an optimization to Vitaliy Kiselev’s GH2 Hack, curious, isn’t it? I bet that right now Canon is working closely with the Magic Lantern team…

NOT!

I see that as good news, I’m sure that he is giving his feedback as for what he expects for the GH5, what improvements he wants from the GH4, but obviously he is probably working more closely on the codec side and how to make the most of it.

My guess is that he is helping they tweak the codec to find the right balance between higher bit rate & quality and still keeping the camera cool. I don’t know if they are making something based on the AVC Ultra, if they are in touch with the Varicam team of it they are working on something completely new like HEVC/H.265.

Having him working closely with Panasonic and even attending Photokina together, giving interviews with Panasonic people, that makes me think that HEVC might not be so far-fetched.

As I already debated about it before, I know some people are against H.265 because of transcoding time but HEVC is the present AND future. All new hardware from smartphones to GPU already support H.265 and although I’m not even equipped for that, I’d prefer Panasonic to be ahead than late. More importantly, you can always use Proxy Media for a better editing experience.

Someone that went all the way into hacking a camera like Mr. Driftwood did and is involved in this will probably want to make the GH5 a heck of a camera, don’t you think?

Whatever codec it may be, I would like to think that it will have a very thoughtful and nice balance between bit rate, quality and practicality. Cheers for that!

Audio Interface and the Grip

It was just a mock up but the audio interface on top of the hot shoe makes me think that the hot shoe might have an electronic interface like Sony already use in their cameras.

That’s much better than the weird and chunkier YAGH Interface Unit. To be fair, Panasonic was a bit ahead of time and there was no 4K recorder that could handle 10-bit 4:2:2 HDMI output at the time, so they developed their own thing to make sure that feat was available. The problem though is that it still had a lot of issues, not just its design.

This new audio interface provides audio controls and two XLR port, turning the GH5 into a great system. Based on what other manufacturers offer for similar solution, I think it might cost around $400~600.

The GH4 already have one of the best battery life in any hybrid camera but nonetheless, Panasonic is bringing a new grip for the GH5, that way you certainly can shoot without worrying about anything, maybe they can provide extra feats like Fuji did with the X-T2’s Grip Booster and it will be useful to power up the audio interface unit.

New Feats: What to Expect?

Panasonic came up with all sort of tweaking that Sony never offered like Luminance Levels, 180 degree shutter, Master Pedestal, etc. I wonder what new addictions can we expect from Panasonic.

I’ve already seen people talking about Rec.709 Preview which can assist people when recording in V-log L. I wonder if Panasonic will provide new flavors of V-Log L, that would be nice.

I would like the GH5 to have 120 fps slow motion and a 240 fps as well, even if it has some cropping, but still maintaining a 1080p resolution. Being capable of 4K 60fps means that this is a heck of a sensor, even more so if it’s from a full readout but we’ve to wait for more information on that.

If it’s really 4K 60fps from a full sensor readout, it means that this is as fast as the Olympus E-M1 MK II that is capable of 60fps 20MP burst from a full sensor readout. Which might be a sign that once again, Panasonic and Olympus are sharing the same base sensor, each one with its own tweakings — which always give them the margin to claim that it’s NOT the same, but for practical matters and performance wise, they are the same.

Having a 4x smaller sensor than FF also has its advantages, it should have faster full sensor readout and better rolling shutter. So wishing for good quality 240 fps might not be too off the table, plus, Sony already offer that in their cameras, Panasonic has to step up their slow motion game too.

There are some minor implementations that can make a whole lot of difference, it’s a simple matter of doing it. Since Panasonic already adopted Anamorphic recording, why not a visual guidelines for different aspect-ratio?

Or how about all flavors of Auto-ISO settings?

I still don’t understand why there is no Auto-ISO function for Full Manual Mode in Panasonic’s cameras, that’s so important in video. You set a range of ISO just so there is not a drastic change in noise and you let the camera change the ISO according to the scene while you control it via exposure compensation. Fuji kills it when it comes to these details, these not a major features but it makes life so much easier.

AF Improvements

But I hope that the biggest of all improvements is the AF, this is what Panasonic has been lagging behind and people really want better tracking AF. Canon already have the Dual Pixel AF, Sony stepped up with the A6300 and now Olympus are making bold claims about the new cross-type 121-point Dual Fast AF from the E-M1 MK II. The new Fuji X-T2 is out there and it seems that the new AF is not just fast but tracks well.

As tests and reviews are starting to surface, a lot of people are praising Fuji X-T2’s Focus Tracking and it seems that even Sony’s manager admitted in an interview that their cameras are still not on the same level.

Are fast-focusing mirrorless cameras like the Fujifilm X-T2 a threat to Sony Alpha 7-series customers?
KM: Yes. In terms of speed we have learned a lot from Fujifilm, Canon and other competitors. There’s still a lot more to learn of course and we don’t have the same kind of weapon right now. We have to create something new.

It’s clearly that this is the new step for mirrorless cameras, all major players are heavily investing in AF improvements and Panasonic can’t be an exception in such important matter.

Check AF and some 4K footage after 5:30

As accessible as gimbals have become and with all sort of other tools in which reliable AF is critical, having a decent tracking AF has become a necessity. Focus hunting has always been a nightmare, if would be nice if Panasonic could eliminate both altogether.

Combine that with the touch focus controls and this gives filmmakers everything they need for a reliable focus tool. For a lot of situations I prefer MF but I don’t quite like fly-by-wire focus so getting smooth transitions from different focus points using the touch screen is a great tool, even better if Panasonic could provide some focus distance measurements while filming.

A step up from that would be to be able to program two focus points to function buttons. With the GH5 being such a run & gun tool, the possibility of having programmable pull focus ability would make a lot of sense and it would be a terrific tool. Imagine yourself as a one-man-crew, controlling the camera through the app and easily making more complex focus and defocus shots.

Since the GH2, it’s noticeable how Panasonic has been working much closer to filmmakers, receiving feedback and improving their cameras with it. The GH4 was already such a nice surprise, I hope they keep that streak alive with the GH5. Aside from the IBIS, we already know all major features and what to expect from it, but the small details often makes much more difference when you are out there in the field filming.

Part 1: Overheating Gate and IBIS rant!

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

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

Extra: The Sensor has to be Multi-Aspect!

Edit:

September, 28th: Corrected Nick Driftwood as the guy that created the GH2 Hack to the guy that created the GH2 Driftwood Hack version.