Panasonic GH4 vs Sony A7S compared - who wins the 4K battle on paper?

[yiomo]

Sunyata, from your test it seems to me that indeed the biggest difference comes not from 420 to 422 but from 8bit to 10bit.  

 

Araucaria, it seems you are claiming that slog2, which is a flat profile, is only marketing and has no value at all, since it will produce banding when grading. But the again how many of these A7s would Sony sell, if one of their biggest marketing "weapons" - slog2, proves "worthless" in post?

On the other hand there are so many GH4 videos out there, most of them shot in camera 4k, so 8bit, which seem to grade fine. And almost all of them shoot flat (cinelike D) and grade heavily (luts +filmconvert +curves +additional tweaking). Why isn't this footage worthless?

 

 

Another thought, Isn't there any chance that the xavc-s compression is more flexible to work with, despite it being 8bit?

[Guest Ebrahim Saadawi]

You are obsessing too much over numbers and specs on a piece of paper. I have to remind you that you cannot judge a product solely based on the spec sheet. 

You are claiming the A7s image is unusable, without even ever using one.
Or even seeing anyone else use one.
You are also claiming the S-log2 feature on the A7s is useless, without even ever trying it.

What's even more absurd is claiming that dynamic range is worthless in 8 bit cameras.

Based on this, the FS700 has no advantage in DR over the t2i since they are 8bit, 4:2:0 cameras, and thus the fs100 DR is worthless. OK. I will not look into DR when purchasing an 8 bit camera again because it's worthless

_________________________________

I would like to take a moment to remind you of a camera, that was 8 bit, 4:2:0, and utterly disappointing on paper, but in actual usage, it produced one of the highest image quality ever produced by an HD camera: the Canon C100/C300. 

No one would call their image unusable or worthless, and they are the most used cameras in the broadcast/news industry, and even in Hollywood theatrical-released movies. So if you find their image unusable to you, you are an extremely specific high-end customer, that requires 10 bit specifically, and then, yes, the A7s and C300 are not for you. 


About S-log2, it's not worthless on an 8bit camera. We've seen excellent implementations of Log profiles in 8bit cameras, again as in the Canon Log in Canon Eos Cinema cameras. No one is claiming C-log is useless there. It truly does expand dynamic range in that 8 bit camera, just needs careful grading, and I believe it will be similar or better on the A7s, but I don't know that for sure, we'll have to actually use it in order to see if it's worthless or useful. 


Another examples of great images coming out of 8 bit cameras,
-the GH4: 8 bit and 4:2:0 and one of the best HD images on the market.
-the FS100: 8bit and 4:2:0
-the FS700: 8bit and 4:2:0
-the 1DC, A6000, and many more!

So please don't claim the A7s images are bad, or useless before using it just because it's 8bit and 4:2:0. What really makes a camera's image look fantastic is the sensor design, the downsampling technology, the Codec implementation, the colour science, the dynamic range, sensitivity, detail reproduction, etc

And I have very high hopes for this camera.

I imagine C100/300-type images but plus + fullframe aesthetic + incredible sensitivity + 4K output for a great monitor on the hotshoe + adaptable mirrorless mount, and all that in a size of a compact camera! Please Sony, don't let me down.

 

[Nikkor]

Sunyata, from your test it seems to me that indeed the biggest difference comes not from 420 to 422 but from 8bit to 10bit.  

 

Araucaria, it seems you are claiming that slog2, which is a flat profile, is only marketing and has no value at all, since it will produce banding when grading. But the again how many of these A7s would Sony sell, if one of their biggest marketing "weapons" - slog2, proves "worthless" in post?

On the other hand there are so many GH4 videos out there, most of them shot in camera 4k, so 8bit, which seem to grade fine. And almost all of them shoot flat (cinelike D) and grade heavily (luts +filmconvert +curves +additional tweaking). Why isn't this footage worthless?

 

 

Another thought, Isn't there any chance that the xavc-s compression is more flexible to work with, despite it being 8bit?

I exagerated a little bit, but there is really a problem with skin tones when using flat profiles in a 8bit codec, it just doesn't look natural anymore and you have to nail exposure otherwise they will look terrible, so in a lot of cases you will need to light the faces to make a shot possible (when there is a lot of DR). 10bit would make that a little bit more flexible.

 

Anyway, I plan on buying this beast once it comes down in price and there are good recorders.

[pablogrollan]

I exagerated a little bit, but there is really a problem with skin tones when using flat profiles in a 8bit codec, it just doesn't look natural anymore and you have to nail exposure otherwise they will look terrible, so in a lot of cases you will need to light the faces to make a shot possible (when there is a lot of DR). 10bit would make that a little bit more flexible.

 

Aren't you supposed to nail exposure? All these complains sound a little bit like wishing for a camera that would render a proper DP and proper lighting useless... which ain't gonna happen!

Cameras have light meters, histograms and now even an EVF that will give you a very approximate preview of what's being recorded. The issue is that you are supposed to expose correctly! We all make mistakes and regret the shot that could have been but we missed. The better we are the less we miss and still newer 8 bit codecs allow for a 1-1.5 stop correction, which should be enough. Let's not use technology to become lazy or as an excuse for our lack of technique/attention.

[Guest Ebrahim Saadawi]

Disgaree that 10 bit codecs, 4:4:4 and raw shooting are for lazy cinematographers, or that wishing for a camera to have any of these is being lazy, it is not...

But yes I agree, when implemented well, an 8 bit 4:2:0 codec, can be enough for nearly all applications, including high-end theatrical releases and broadcast.

[Nikkor]

Aren't you supposed to nail exposure? All these complains sound a little bit like wishing for a camera that would render a proper DP and proper lighting useless... which ain't gonna happen!

Cameras have light meters, histograms and now even an EVF that will give you a very approximate preview of what's being recorded. The issue is that you are supposed to expose correctly! We all make mistakes and regret the shot that could have been but we missed. The better we are the less we miss and still newer 8 bit codecs allow for a 1-1.5 stop correction, which should be enough. Let's not use technology to become lazy or as an excuse for our lack of technique/attention.

I'm not talking about correcting exposure afterwards, it doesn't even work really well with 14bit raw files coming from a d800.

You have to nail exposure on the skin, which means bringing it into a place where you get enough information, but later on in post you might not want that exposure for the whole scene so you have to change it. With 10bit you might be able to use the correct exposure for the whole scene to begin with because you have 4times the information everywhere.

I'm talking about skin here, but that's only one reason.

I mean, this is well known, if there were no issue why would anybody want to use 10bit.

[sunyata]

 8 bit 4:2:0 codec, can be enough for nearly all applications, including high-end theatrical releases and broadcast.

 

Ebrahim, for over a decade now 10bit log has been the baseline for digital to film for theatrical projection. It's only gone higher internally since.

 

A Xenon projector is a higher quality gamut than what you see on your monitor, and consequently less forgiving. Unless you have a 10bit monitor to finish on, you might not realize the artifacts and banding until you're in a screening room. You also have to assume that the color will be different when projected, so you need to provide enough overhead for a colorist to make final changes.

 

Today ACEs format is being pretty broadly adopted for finishing which might be overkill, but that's where we're headed.

 

If you want to know the lowest common denominator for theatrical projection though, I would say 10bit log. Not sLog in linear space, but logarithmic gamma encoded.

 

p.s. I'm not saying anything about 8bit is "useless", I'm just addressing your comment above regarding "high-end theatrical releases".

[GMaximus]

So please don't claim the A7s images are bad, or useless before using it just because it's 8bit and 4:2:0. What really makes a camera's image look fantastic is the sensor design, the downsampling technology, the Codec implementation, the colour science, the dynamic range, sensitivity, detail reproduction, etc

 

Are there any examples of XAVC footage in A7s yet?

[pablogrollan]

Disgaree that 10 bit codecs, 4:4:4 and raw shooting are for lazy cinematographers, or that wishing for a camera to have any of these is being lazy, it is not...

But yes I agree, when implemented well, an 8 bit 4:2:0 codec, can be enough for nearly all applications, including high-end theatrical releases and broadcast.

 

Never said 4:4:4 and Raw were for lazy cinematographers or anything of the like, but that stating that they are absolutely necessary to get good results is an exaggeration. 8bit 4:2:0 is limiting, or should I say challenging, but being meticulous you can make it shine. Act of Valor and a bunch of House M.D. episodes were shot with 5DMKII, and whatever the limitations or problems they faced, with some extra work they were overcome.

 

I just wanted to express that by asking for better and better specs we seem to be forgetting that the best final product is usually the one that had the best production work involved, and that the increasing trend of "fixing it in post" should not be the way to go.

[hmcindie]

Ebrahim, for over a decade now 10bit log has been the baseline for digital to film for theatrical projection. It's only gone higher since.

 

 

That's a misunderstanding of the whole modern post workflow. Even just a couple of years ago, the material could be 8-bit all the way through until it hits grading where they generated higher bitdepth images (but that were originally 8bit) that are sent to make the DCP.

 

And who noticed anything? Nobody that's who. We've had shots done with the Red Epic where we replaced orignal 5k RAW-files (that were accidentally lost) with some prores proxy HD-files and no one noticed anything when those shots hit the projector. Haha.

 

You guys drive me crazy.

 

And when you talk about xenon projectors having a great gamut... The contrast is still shitty horrible.

[sunyata]

That's a misunderstanding of the whole modern post workflow. Even just a couple of years ago, the material could be 8-bit all the way through until it hits grading where they generated higher bitdepth images (but that were originally 8bit) that are sent to make the DCP.

 

And who noticed anything? Nobody that's who. We've had shots done with the Red Epic where we replaced orignal 5k RAW-files (that were accidentally lost) with some prores proxy HD-files and no one noticed anything when those shots hit the projector. Haha.

 

You guys drive me crazy.

 

And when you talk about xenon projectors having a great gamut... The contrast is still shitty horrible.

 

Hahah... you're driving ME crazy. First of all, criticizing digital projectors is fine, but a Xenon projector refers to the bulb, and it's the most common bulb used in movie theaters today. I guess you're thinking of the contrast on a consumer digital projector? I don't know.

 

Look, I'm kinda tired, I don't want to go on a long technical smackdown, just believe me, I work in flame on a finishing station, as well as do other sundry TD things, and you don't finish with 8bit files in a professional environment and res up for a master.. not unless you have a client that doesn't care? I guess you are telling me that it's standard now, or for the last 2 years, to use 8bit as your digital intermediate format? Is this what I'm missing?

 

The fact that you could swing this swapping of an 8bit proxy in place of missing Red Epic footage does not mean that it's now okay for everyone that works in post to start finishing with 8bit Prores.

 

As for who will notice, on this topic of "high-end theatrical release films" etc, an account rep at some place like E-Film or Deluxe will get the word from a colorist or technician, if it's visible, assuming it get's past your own internal QC. Colorists are trained to look for quality issues, they have the best tools to see the final product. I'm not a director so I'm not familiar with deciding to slide in whatever footage I want at the last minute. What a luxury. 

 

Projectors can emit whites brighter than a computer monitor or HDTV and at a wider gamut, it has required at least 10bit log gamma to encode the range for film, a pretty good baseline, which is more like 12bit linear (converted). 8bit in rec709 often looks like TV because it was designed for TV.

 

Again, not saying 8bit 4:2:0 is useless, just responding to some of the wild claims.

[yiomo]

Argh. Just saw a fantastic aquarium clip from the gh4. Wow! What clarity.

But regarding the compression, isn't it true that the A7s sends more data? Not many people talk about that. Since 4k is presumably the main use of the gh4 and this is done in 100mbps- that is 24mbps equivalent to HD, whereas as we know the A7s HD is 50mbps. No?

[GMaximus]

Argh. Just saw a fantastic aquarium clip from the gh4. Wow! What clarity.

But regarding the compression, isn't it true that the A7s sends more data? Not many people talk about that. Since 4k is presumably the main use of the gh4 and this is done in 100mbps- that is 24mbps equivalent to HD, whereas as we know the A7s HD is 50mbps. No?

Those mbps are not about sending data somewhere in the middle, it's just what you get after compression, at the end.

GH4 compresses HD at 100 and even 200mbps, so no. Looks like A7s doesn't have enough processing power to compress 4k with adequate quality.

[yiomo]

Those mbps are not about sending data somewhere in the middle, it's just what you get after compression, at the end.
GH4 compresses HD at 100 and even 200mbps, so no. Looks like A7s doesn't have enough processing power to compress 4k with adequate quality.

The comparison is regarding the 4K to HD workflow with GH4. If you divide the 4 times the pixels of the 4K, you get a 25Mbit/s HD image. The A7s sends double the amount - 50 Mbit/s.
Regarding the 200mbit/s, many reviewers say it is worse than the 100mbit/s .
As for the 100mbit/s it might be better than the A7s, but this issomething we'll soon find out. Practically few will be using this mode.

[Andrew Reid]

I have seen some externally recorded A7S footage which is secret for now. The friend can't publish yet.

 

I have to say I am absolutely blown away by it.

 

The low light performance and dynamic range transformed the image... the shadows when graded were silky smooth with a fine noise grain, but it had latitude to catch the illumination realistically... and when the light source bounced against the shadows it looked like film... very nice. I believe it was shot externally to an Atomos Ninja... no signs of moire or aliasing and detail was good...a little soft and filmic but not exactly lacking in fine details and would sharpen nicely.

[Nikkor]

I have seen some externally recorded A7S footage which is secret for now. The friend can't publish yet.

 

I have to say I am absolutely blown away by it.

 

The low light performance and dynamic range transformed the image... the shadows when graded were silky smooth with a fine noise grain, but it had latitude to catch the illumination realistically... and when the light source bounced against the shadows it looked like film... very nice. I believe it was shot externally to an Atomos Ninja... no signs of moire or aliasing and detail was good...a little soft and filmic but not exactly lacking in fine details and would sharpen nicely.

Oh no, I need money...

 

Anything about the highlights? Do they have a smooth rolloff, or are they like on the GH4?

[Andrew Reid]

That's all I'm saying about it, sorry!

[Guest d5f8611fa423d0e628c016f9d5c93b47]

I have seen some externally recorded A7S footage which is secret for now. The friend can't publish yet.

 

I have to say I am absolutely blown away by it.

 

The low light performance and dynamic range transformed the image... the shadows when graded were silky smooth with a fine noise grain, but it had latitude to catch the illumination realistically... and when the light source bounced against the shadows it looked like film... very nice. I believe it was shot externally to an Atomos Ninja... no signs of moire or aliasing and detail was good...a little soft and filmic but not exactly lacking in fine details and would sharpen nicely.

 

This was 1080p 422 8 bit right?

[yiomo]

from  Sony : Dynamic Range extended to 15.3 stops as sensor RAW output  :) 

[yiomo]

sorry. It seems this info has been around for a long time, but I just saw it.

 

I wonder though what does RAW output mean? Is that before compression is applied?