Sigma Fp review and interview / Cinema DNG RAW

[KnightsFan]

8 hours ago, paulinventome said:

That is the very point of bayer sensors, no? I don't know whether you're a developer or have had a chance to experiment with different debayer techniques but that is precisely what is happening for the 2 pixels for every pixel that are not recorded. The reconstruction algorithms are really clever, taking into account edges and gradients

Yes, it is, which is why we get so many color problems from bayer sensors!

I suspect I have less development experience than you here, but I've done my share of fun little projects with procedurally generating imagery, though usually in RGB. My experience with YUV is mostly just reading about it and using it as a video file.

8 hours ago, paulinventome said:

At the end of the day the proof are in the images. That 8 bit RAW from sigma is much better than it has any right to be and i spend lots of my days deep in pixels - from Red to Arri and the other end of the spectrum as well. I hate YUV with a passion because it's caused me so many post headaches.

I'll dig a little more at the images. From my initial look, I don't see any extra flexibility in the Raw vs. uncompressed YUV (assuming that the Raw will eventually be put into a YUV format, since pretty much all videos are). The benefit I see is just the lack of compression, not the Raw-ness. I'm not saying the 8 bit raw is bad, but uncompressed anything will have more flexibility than anyone needs.

[deezid]

3 hours ago, kye said:

Yes, that holds up very well..  even with very subtle tones on her face there's no visible banding or artefacts (even on your upload).  

Makes me wonder if I want to keep my S1H with its great color science and dynamic range but codec and even worse temporal NR issues and get this one instead...
Looks even better than the Pocket 4K did before Braw.

[cpc]

Here are the two C5D raw samples, but made Premiere CC compatible, if anyone wants to play with the image in Lumetri:

https://drive.google.com/open?id=1c3DAPF_heybRJ1oL_ohgjRolBcKWZkwt

[CaptainHook]

22 hours ago, deezid said:

Quite impressed about the RAW samples also. Interpreted them as BMD Film and used my Soft film LUT to convert to Rec709

FYI if you interpret a (non Blackmagic Design) DNG in Resolve as "BMD Film" this will be Gen 1 which means for gamut there is NO transform - you are getting the sensor spectral response to colour which is not represented by 3 primaries like most gamuts and can't be treated as such. That would mean to "accurately" convert to Rec709 you would need the spectral response data for the sensor in the camera to calculate the transform to Rec709 for an illuminants given colour temperature, or by shooting known targets under various illuminants and doing a regression fit from there. It means multiple transforms depending on your white balance.

The 709 gamut option in Resolve for DNGs is using the 2 colour matrices and "AsShotNeutral" tags (for white balance/tint) provided in the DNG metadata which have been calculated by the manufacturer (using one or both the methods described above) to provide a transform to XYZ for the given white balance (the matrices are actually used to transform from XYZ to sensor space but you can invert that) and from XYZ a standard conversion to 709 is performed. The ACES pipeline in Resolve also uses the same matrices in the DNG to convert to XYZ and then to ACES primaries.

Of course many people just graded BMCC/Pocket footage with Gen 1 by hand and were also pleased with the result, but one should not expect the sensor response to appear in a meaningful way on a typical display without some kind of transform (calculated or done manually).

But this is mostly to say if someone created a LUT or otherwise for BMCC/Pocket Gen 1 DNG footage, it will not be "correct" for other cameras (it may coincidentally look okay but that may also be scene specific). And most importantly for our cameras our others, if grading or creating a LUT etc for footage left in sensor space you need to adjust the correction/transform for illuminants with different colour temperatures. I.e Something done for footage shot under daylight will not usually work well for something shot under tungsten.

If you use the Rec709 gamut option, you could use the CST OFX plugin to transform to another gamut safely as the RAW decode and CST plugin will not clip data and the white balance specific response has been already taken care of (the way the manufacturer wants done) in the transform to 709. This is the workflow I would recommend with such footage. YMMV.

[Llaasseerr]

3 hours ago, CaptainHook said:

FYI if you interpret a (non Blackmagic Design) DNG in Resolve as "BMD Film" this will be Gen 1 which means for gamut there is NO transform - you are getting the sensor spectral response to colour which is not represented by 3 primaries like most gamuts and can't be treated as such. That would mean to "accurately" convert to Rec709 you would need the spectral response data for the sensor in the camera to calculate the transform to Rec709 for an illuminants given colour temperature, or by shooting known targets under various illuminants and doing a regression fit from there. It means multiple transforms depending on your white balance.

The 709 gamut option in Resolve for DNGs is using the 2 colour matrices and "AsShotNeutral" tags (for white balance/tint) provided in the DNG metadata which have been calculated by the manufacturer (using one or both the methods described above) to provide a transform to XYZ for the given white balance (the matrices are actually used to transform from XYZ to sensor space but you can invert that) and from XYZ a standard conversion to 709 is performed. The ACES pipeline in Resolve also uses the same matrices in the DNG to convert to XYZ and then to ACES primaries.

Of course many people just graded BMCC/Pocket footage with Gen 1 by hand and were also pleased with the result, but one should not expect the sensor response to appear in a meaningful way on a typical display without some kind of transform (calculated or done manually).

But this is mostly to say if someone created a LUT or otherwise for BMCC/Pocket Gen 1 DNG footage, it will not be "correct" for other cameras (it may coincidentally look okay but that may also be scene specific). And most importantly for our cameras our others, if grading or creating a LUT etc for footage left in sensor space you need to adjust the correction/transform for illuminants with different colour temperatures. I.e Something done for footage shot under daylight will not usually work well for something shot under tungsten.

If you use the Rec709 gamut option, you could use the CST OFX plugin to transform to another gamut safely as the RAW decode and CST plugin will not clip data and the white balance specific response has been already taken care of (the way the manufacturer wants done) in the transform to 709. This is the workflow I would recommend with such footage. YMMV.

Thank you for talking some sanity on this oft-misunderstood subject.

[paulinventome]

14 hours ago, KnightsFan said:

I'll dig a little more at the images. From my initial look, I don't see any extra flexibility in the Raw vs. uncompressed YUV (assuming that the Raw will eventually be put into a YUV format, since pretty much all videos are). The benefit I see is just the lack of compression, not the Raw-ness. I'm not saying the 8 bit raw is bad, but uncompressed anything will have more flexibility than anyone needs.

If you're digging then look at these aspects:

- Highlight reconstruction, if you're in Resolve or similar then from a native sensor colourspace it is easier to recreate missing channels at clipping. If your are in a white balance baked format then the clipping has already happened. It's quite common for sensitivity of RGB on the sensor to be quite different to each other. In a baked format these have been white balanced and so some of the channels would have been clipped to do that. There is no headroom in YUV. In some situations there is up to a stop of detail to be recovered. Helps especially with skies, clouds and avoiding that horrible too cyan look.

- White balancing again, creatively or otherwise it's a massive boon to balance in the grade. White balance both YUV and RAW and tweak the settings a little bit and see that you'd get smoother results from RAW

- Different debayering approaches for different uses.

- Retention of noise and the ability to reduce that without dealing with compression, especially in the dark areas.

Now the one thing is that sigma are dumping out DNGs with all the matrixes embedded within which is great, but actually they could offer more in terms of specific transforms, like Black Magic do. As mentioned above, sensor response is not defined as well as a colourspace, the edges of the gamut can be all over the shop and when dealing with outlying colours the method to bring them into gamut can be challenging. It took Red quite a few years to get to IPP2 which provides some excellent gamut mapping - specifically designed for each one of their sensors. It could be that sigma are doing some colour work from sensor before dumping into RAW - these issues are usually seen mostly in flouro and LED lights - car brake lights and so on. Typically these are outside of 709 space and so mapping those are very important. 

It's too early to tell with the sigma DNGs how this will pan out - we've only seen a couple...

cheers
Paul

 

[Llaasseerr]

22 hours ago, paulinventome said:

Now the one thing is that sigma are dumping out DNGs with all the matrixes embedded within which is great, but actually they could offer more in terms of specific transforms, like Black Magic do.

 

It would be great if Sigma made an ACES IDT based on measuring the sensor's spectral sensitivity data. From the rawtoaces documentation on Github:

The preferred, and most accurate, method of converting RAW image files to ACES is to use camera spectral sensitivities and illuminant spectral power distributions, if available. If spectral sensitivity data is available for the camera, rawtoaces uses the method described in Academy document P-2013-001 (.pdf download)

[ntblowz]

Fp is about the same size as m6ii

[Brian Williams]

Today’s the day! Except neither of my orders from BH or Adorama have shipped, and no reports of anyone else’s orders having been shipped so far. Hope this isn’t a Blackmagic-type deal where they mail out two cameras just so they can say they met their delivery date.

[Anaconda_]

33 minutes ago, Brian Williams said:

Today’s the day! Except neither of my orders from BH or Adorama have shipped, and no reports of anyone else’s orders having been shipped so far. Hope this isn’t a Blackmagic-type deal where they mail out two cameras just so they can say they met their delivery date.

@Andrew Reid has his.

[Brian Williams]

16 minutes ago, Anaconda_ said:

@Andrew Reid has his.

Yeah, saw that... though Andrew Reid is not of us common folk. 

[Andrew Reid]

Yes I am. Ordered from WEX yesterday, it's in stock. Cost £2399 with the 40mm.

On 10/24/2019 at 1:19 AM, CaptainHook said:

FYI if you interpret a (non Blackmagic Design) DNG in Resolve as "BMD Film" this will be Gen 1 which means for gamut there is NO transform - you are getting the sensor spectral response to colour which is not represented by 3 primaries like most gamuts and can't be treated as such.

I am looking forward to proceeding in Resolve with my Sigma Fp footage as I've been doing for years with Cinema DNG from the 5D Mark III with ML. Was always very happy with the results.

If what you say has a big impact on colour and white balance, hopefully Resolve can have support for Cinema DNG beyond just Blackmagic's own cameras...

Don't make us go back to Premiere

Quote

you use the Rec709 gamut option, you could use the CST OFX plugin to transform to another gamut safely as the RAW decode and CST plugin will not clip data and the white balance specific response has been already taken care of (the way the manufacturer wants done) in the transform to 709. This is the workflow I would recommend with such footage. YMMV.

Good to know thanks.

[Brian Williams]

28 minutes ago, Andrew Reid said:

Yes I am. Ordered from WEX yesterday, it's in stock. Cost £2399 with the 40mm.

Once again, I'd rather be in Europe

[Andrew Reid]

It's a special Brexit price.

[Rob6]

@Andrew Reid, 

I can't wait to see your review!! I would love to hear your thoughts on how the Sigma mc-21 adapter works with your canon lenses. Hopefully all the canon lenses work without any issues. I wish they could have made it 60p in raw. I guess it would get too hot...

 

 

[CaptainHook]

18 hours ago, Llaasseerr said:

It would be great if Sigma made an ACES IDT based on measuring the sensor's spectral sensitivity data. From the rawtoaces documentation on Github:

The preferred, and most accurate, method of converting RAW image files to ACES is to use camera spectral sensitivities and illuminant spectral power distributions, if available. If spectral sensitivity data is available for the camera, rawtoaces uses the method described in Academy document P-2013-001 (.pdf download)

Its not needed in Resolve as Sigma have already added the required matrices and linearization table (for their log encoded versions) so you can convert to ACES as outlined. I can't speak for other apps or workflows though.

4 hours ago, Andrew Reid said:

If what you say has a big impact on colour and white balance, hopefully Resolve can have support for Cinema DNG beyond just Blackmagic's own cameras...

Resolve has support through RCM (Resolve Colour Management) and CST for all major camera manufacturers log curves and gamuts so you could interpret the DNGs using RCM for instance into any gamma/gamut correctly for the given white balance setting if you would prefer. But that's why i recommend the Rec709 approach in Resolve for the Sigma DNGs (or RCM as mentioned would also work). One major issue for DNG for us was that there is no standard way defined to interpret DNGs into different colour spaces or even ISOs through metadata which was a big focus for Blackmagic RAW*. This is why DNGs from our cameras look different across various apps, because they are free to interpret them as they want. So we had the same problem with other apps and our DNGs, but it was worse as most other apps don't have an equivalent to RCM or CST to manage the transform into Blackmagic colour spaces.

*That's ignoring how slow DNG is to decode (relatively) and that even at 4:1 compression, DNGs from our cameras had image artefacts in certain scenes and situations we weren't happy with (5:1 was evaluated to be not useable/releasable to the public) which is a real problem as resolution and frame rates increase and is even a problem for recording 6K to affordable media (or even 4.6K at high frame rates). Even if we weren't put into the situation to drop DNG when we did, IMHO it's unlikely it would be a good viable solution long term with where things are heading and the amount of complaints about DNG we got/saw and had ourselves. It was great when the first Blackmagic cameras were HD (2.4K) and 30fps, but that even Adobe themselves seemed to have no interest in maintaining or developing it further it's limitations now can't be ignored.

[Lars Steenhoff]

I still don't understand why uncompressed CDNG had to be dropped, Uncompressed was never an issue right?

[paulinventome]

16 hours ago, Andrew Reid said:

Yes I am. Ordered from WEX yesterday, it's in stock. Cost £2399 with the 40mm.

 

Tempted, but not yet... I ought to wait for Komodo.

But what i would love to know is...

1. See some 4K 10bit DNGs at 25p, nice full range with skies and everything in
2. In stills mode the kind of shutter speed we can get. It dawned on me with an electronic shutter then it might be pretty useless as a stills camera in fast situations, this would diminish it's appeal as a replacement for a dSLR.

Looking forward to some feedback
Paul

 

 

[Andrew Reid]

13 hours ago, Rob6 said:

@Andrew Reid, 

I can't wait to see your review!! I would love to hear your thoughts on how the Sigma mc-21 adapter works with your canon lenses. Hopefully all the canon lenses work without any issues. I wish they could have made it 60p in raw. I guess it would get too hot...

The only thing I wish the Fp had was phase-detect on-chip autofocus.

And maybe an articulated screen like the RX1R II

It is an amazing, unique camera as it is, and an absolute blast. Last time I had this much fun was when I first picked up a GH2 all those years ago.

60p in 12bit 1080p RAW.

4K 60p RAW Cinema DNG file sizes would be astronomical. Like 6 min per 128GB or something crazy.

Yes, I wish it had 4K/60p full frame 10bit but we are not in year 2022 yet  Not even S1H can do it. Super 35mm mode.

[mercer]

35 minutes ago, Andrew Reid said:

60p in 12bit 1080p RAW.

I’d love to hear a comparison between 1080p ML Raw at 14bit vs Sigma’s 1080p Raw at 12bit in your review.