SIGMA FP with ProRes RAW and BRAW !

[bjohn]

33 minutes ago, Anaconda_ said:

Does anyone know if Sigma and BMD have been in talks for Braw?

Someone does, of course, but nobody here unless they work for Sigma or BMD (and they wouldn't say!). But it's worth noting that Sigma has listed the BMD Video Assist as a "recommended accessory" on their fp website for a while now, well before the firmware was released, and more to the point I strongly doubt they would invest the time into developing a feature/capability that relies on a third party and then announce it to the world without ever having worked with that third party to ensure it works.

Most likely what's going on is that BMD has other features and fixes to shoehorn into its next firmware update for the new Video Assists, so there will be some delay.

It looks like the older Video Assist 4K can already record ProRes from the fp, not sure if anyone has tried that yet. In my experience, Prores HQ has almost as much flexibility in terms of changing white balance, ISO, etc. as you get from raw; BRAW files will be smaller of course and have a bit more latitude for change. But I wouldn't sniff at Prores HQ.

[Lars Steenhoff]

Yes sigma and bm worked together to make this happen, its not a secret

[androidlad]

ProRes HQ cannot compare to ProRes RAW for adjusting white balance or ISO, because RAW is linear, scene-referred, the results are much better than gamma encoded color spaces. You can linearise but it adds quite a few additional steps.

[Anaconda_]

11 minutes ago, bjohn said:

It looks like the older Video Assist 4K can already record ProRes from the fp, not sure if anyone has tried that yet.

It can record ProRes from any camera or any other HDMI source. ProRes isn't camera/sensor dependent.

12 minutes ago, bjohn said:

I strongly doubt they would invest the time into developing a feature/capability that relies on a third party and then announce it to the world without ever having worked with that third party to ensure it works.

But this update isn't specifically for Braw. They've enabled raw over HDMI, which Atomos can make ProResRaw already. Braw is more specific though, so I was thinking they've said 'we have given BMD the possibility to record Braw, it's up the them to finish it off'. I'm sure that's not the case, but thought it might be an interesting question.

Blackmagic previously revealed Braw capable cameras, like the EVA1, way before they released the updates for the VA that actually enabled the possibility, but as far as I can tell, haven't said anything about the FP. That said, they announced that before the new VA was even available, so similar to what Sigma have done here I guess.

[bjohn]

58 minutes ago, androidlad said:

ProRes HQ cannot compare to ProRes RAW for adjusting white balance or ISO, because RAW is linear, scene-referred, the results are much better than gamma encoded color spaces. You can linearise but it adds quite a few additional steps.

On the Blackmagic Design forum, Dmitry Shijan demonstrated how if you shoot at the camera's native ISO and "native" white balance (in the case of the Micro Cinema Camera, about 5500-5600), Prores HQ has exactly as much flexibility in terms of adjusting ISO and white balance as raw 3:1.  I agree that in general you'll get more flexibility from raw, but ProRes HQ is actually quite flexible.

[Phil A]

20 minutes ago, bjohn said:

On the Blackmagic Design forum, Dmitry Shijan demonstrated how if you shoot at the camera's native ISO and "native" white balance (in the case of the Micro Cinema Camera, about 5500-5600), Prores HQ has exactly as much flexibility in terms of adjusting ISO and white balance as raw 3:1.  I agree that in general you'll get more flexibility from raw, but ProRes HQ is actually quite flexible.

But the fp has no log profile so you record Rec709 with strong contrast and saturation baked in. It doesn’t work as you think unfortunately. You can also record Sony A7s externally into ProRes, It’s still not gonna be better than what the camera can output.

[bjohn]

6 minutes ago, Phil A said:

But the fp has no log profile so you record Rec709 with strong contrast and saturation baked in. It doesn’t work as you think unfortunately. You can also record Sony A7s externally into ProRes, It’s still not gonna be better than what the camera can output.

Ah good point, I forgot about the lack of log profile, which of course isn't an issue with raw but would be an issue with ProRes. Got it, sorry for misunderstanding!

[Llaasseerr]

1 hour ago, bjohn said:

On the Blackmagic Design forum, Dmitry Shijan demonstrated how if you shoot at the camera's native ISO and "native" white balance (in the case of the Micro Cinema Camera, about 5500-5600), Prores HQ has exactly as much flexibility in terms of adjusting ISO and white balance as raw 3:1.  I agree that in general you'll get more flexibility from raw, but ProRes HQ is actually quite flexible.

The main issue for me with ProResHQ is chroma subsampling. You also miss out on some highlight reconstruction options, but that's just putting data in to the image that was not there. But I agree, ISO and white balance operations are just rgb multipliers so they are not particularly destructive.

To replicate what happens in linear raw you just need to delog the footage and if need be set the gamma to 1.0 before you do those operations, or use the correct mathematical operation in log space (add vs multiply). This will work in ACEScc log encoding.

Edit: this is assuming you're actually log encoding your ProRes which we can't do with this camera. I'm personally fine with raw, but there needs to be an accurate monitoring method. Accurate to your final intent that is, since the raw image without context is meaningless.

[Lars Steenhoff]

Use "color mode off"for monitoring exposure in raw.

It gives the most accurate image for zebra's

And if you use an external monitor you can load the LUT for the final intended look.

[Llaasseerr]

1 hour ago, Lars Steenhoff said:

Use "color mode off"for monitoring exposure in raw.

It gives the most accurate image for zebra's

And if you use an external monitor you can load the LUT for the final intended look.

I'd love to know more about this mode. From what I saw, it doesn't look like anything useful except they did not apply the s-curve and gamut transformation, and it still looked gamma encoded. 

A linear raw image can be transformed by your lut to your final output display look, but it needs to first be in a 0-1 space. There are two typical ways of doing this.

1. First transform to log as a shaper lut then apply your look lut which is a typical log to Rec709 lut maybe with a print film emulation as well.

2. The "none" image may be linear, but to retain all the highlight information a raw image must be exposed down. This is how tools like DCraw export images to disk as 16 bit integer files without any dynamic range loss. In order to apply your lut, you need to first adjust the exposure back to what it's meant to be, then transform to a log shaper lut, then proceed with the shaper lut->log to rec709 combo.

For this to be accurate, at every step of the way you need to know what the colour transform is so that you can account for it in your lut creation.

[Lars Steenhoff]

Thanks for explaining the steps to achieve a proper lut, I may look into making one at some point

Right now I'm not too worried about achieving the final look at shooting time myself, I just want to know if I'm exposing properly.

The rest I can deal with in Resolve

[imagesfromobjects]

Guys, there *is* a LOG profile added. It's called Color Mode = OFF.

 

May want to add that to the article, a few people have reiterated the misinformation in this thread.

[Lars Steenhoff]

2 hours ago, imagesfromobjects said:

Guys, there *is* a LOG profile added. It's called Color Mode = OFF.

 

May want to add that to the article, a few people have reiterated the misinformation in this thread.

Its not a log profile, if it was why would sigma apologise for not making a log profile?

but its a good option to use nonetheless.

Why do you feel that it is a log profile?

 

[Andrew Reid]

It seems to be some sort of flat profile now in the Off mode. Desaturated, brings the shadows up.

Definitely seems to be more "Flat profile" than LOG but still interesting to further experiment with.

[Chris Whitten]

Yep, the Sigma rep in the official  video said log profile was not possible.

[Andrew Reid]

But Flat is.

The question is this... How close to LOG is it? Is it LOG by another name? Did Sigma have to change the naming convention for licensing reasons with Sony for their sensor?

[kuau]

Not to beat a dead horse, yet it is my understanding that shooting in RAW = no profile at all so no LOG. One sets the desired look / profile in the NLE which handles the debayer process. LOG is a baked in profile when shooting in anything except RAW, 

Am I wrong ?

[Andrew Reid]

So done a bit more experimenting with the picture profile: Off function.

It does recover highlight detail

It does reveal a lot of shadow detail.

If it barks like LOG, is it a DLOG?

That is the question.

Your RAW question @kuau: yes, RAW is no profile, but can be compressed to a LOG format after. LOG is a form of compressing the full dynamic range of the RAW data into H.264, ProRes, etc.

[imagesfromobjects]

9 hours ago, Lars Steenhoff said:

Its not a log profile, if it was why would sigma apologise for not making a log profile?

but its a good option to use nonetheless.

Why do you feel that it is a log profile?

 

Gotcha. It looks and grades very similarly to SLOG2 out of the a7S I used to have. I may be mistaken, but I think I remember reading that Sigma was putting out a quasi-log because they were having issues with licensing an official one.

 

I'm definitely not here to argue, but I feel that the article is misleading by omitting this. Color Off wasn't here before v2 firmware, so if I had to guess, I would say it's probably what they came up with due to the demand, the deadline and the difficulty in obtaining a license to use an official LOG in the fp.

 

Without digging into the data, I'll just say that offhand, it looks EXACTLY like SLOG-2, minus the yellow tinge. I think it could be very useful for reading the histogram and approximating exposure based off of the LCD alone. Whether or not it's useful to others, or can tide folks over until a real LOG shows up, who knows.

 

What I wish, is that there were more ways to tweak the black levels, curves, hues etc, so that it could be customized more, but hey.

[Chris Whitten]

I watched the Sigma video on Cinematographs. It beggars belief they expended so much effort developing a feature that is kind of an Instagram fx. I find cameras that are trying to walk the line between pro and consumer never quite achieve either.