SIGMA FP with ProRes RAW and BRAW !

[Owlgreen]

At the end of the Cined article on the FP-L was this screenshot of suggested settings for the FP in Davinci Resolve by Sigma themselves. It's dated June 3, 2020. I'm not sure if they've addressed the issue since then. 

[Anaconda_]

'Don't use color wheel adjustments(Lift, Gamma, Gain and Offset) - so curves only? or it's ok to use the LOG wheels - seems like a weird thing to rule out.

[OleB]

9 hours ago, Llaasseerr said:

 

Seriously, whatever you have is good! I just want to check out the ProRes Raw linear gamma /sigma gamut output. An outdoor scene as you describe would be interesting!

By exposing for the clouds so they aren't clipped you are probably underexposing middle grey, so it's just a variant on what I'm talking about. I'm just looking at a more fixed method of shifting the entire highlight DR more towards an Alexa by pushing up the noise floor, so I would shoot with a -3 stop ND for example. It would allow me to "always" expose for middle grey like shooting an Alexa or film, if I assume a +3 exposure compensation in post. I would also try +4 or +5 and see where it breaks. The highlights just clip way too early in this camera, so it could be a solution.

Wish is granted. 🙂 Here we go: https://www.dropbox.com/sh/cgm80q9w682oc19/AADWHieOS-Wka9JuD-GnXerca?dl=0

Same clip I have used for my YouTube video posted above. Recorded at ISO 800 => so ISO 100 in reality. Just so, that the sky highlights would not clip. For obvious reasons I could not prevent the sun from blowing, but thought it would be a good idea to have it in the frame as the ultimate highlight.

Maybe I will do another clip with ISO 3200 in complete darkness soon, will also publish it here.

[Owlgreen]

What would everyone suggest as a good way to correct the distortion of the kit 45mm Contemporary lens in Resolve? A Lens Distortion node with a -0.071 value seems OK, but I'm wondering if there's something more precise. Thanks.

[Llaasseerr]

2 hours ago, Owlgreen said:

At the end of the Cined article on the FP-L was this screenshot of suggested settings for the FP in Davinci Resolve by Sigma themselves. It's dated June 3, 2020. I'm not sure if they've addressed the issue since then. 

Yeah, I don't think Sigma really thought through the colour science aspect at all. So using the settings for a completely different camera is only ever going to be a workaround. Not to say you can't get a pleasing result, but it's not a professional solution. A good counterpoint example is the Digital Bolex. When it came out, there also was not an established workflow or monitoring method for the DNGs and they ended up recommending using the BMD log/color space. However, they did eventually develop a log profile for monitoring over HDMI and they also fleshed out how to accurately interpret the DNGs in a way that was true to the camera, plus they published a white paper. That's really what Sigma needs to do for the next model, or retroactively for the fp.

[Llaasseerr]

1 hour ago, OleB said:

Wish is granted. 🙂 Here we go: https://www.dropbox.com/sh/cgm80q9w682oc19/AADWHieOS-Wka9JuD-GnXerca?dl=0

Same clip I have used for my YouTube video posted above. Recorded at ISO 800 => so ISO 100 in reality. Just so, that the sky highlights would not clip. For obvious reasons I could not prevent the sun from blowing, but thought it would be a good idea to have it in the frame as the ultimate highlight.

Maybe I will do another clip with ISO 3200 in complete darkness soon, will also publish it here.

Thank you! This looks perfect. Like you said, it includes the sensor clipping and also there are fairly dark shadow areas. I'll have a play with this.

[Llaasseerr]

1 hour ago, Owlgreen said:

What would everyone suggest as a good way to correct the distortion of the kit 45mm Contemporary lens in Resolve? A Lens Distortion node with a -0.071 value seems OK, but I'm wondering if there's something more precise. Thanks.

It looks like you could shoot a clip with a grid or checkerboard by walking around it a bit to get some parallax and then 3D track that in the Fusion tab with the 3D tracker node. As part of the track it will calculate a lens distortion model+values that can be plugged into the Lens Distortion node, or maybe it will auto generate a Lens Distortion node with the correct settings already. I haven't used Fusion, but it seems to mirror the process in Nuke.

[Llaasseerr]

3 hours ago, OleB said:

Wish is granted. 🙂 Here we go: https://www.dropbox.com/sh/cgm80q9w682oc19/AADWHieOS-Wka9JuD-GnXerca?dl=0

Same clip I have used for my YouTube video posted above. Recorded at ISO 800 => so ISO 100 in reality. Just so, that the sky highlights would not clip. For obvious reasons I could not prevent the sun from blowing, but thought it would be a good idea to have it in the frame as the ultimate highlight.

Maybe I will do another clip with ISO 3200 in complete darkness soon, will also publish it here.

So I took a look at this, and it does look promising as far as where the highlights have been placed in the Ninja V recording. I noticed in the metadata that the gamut and log curve have been set to Vlog/Vgamut, and the monitoring mode is set to PQ. Now I don't know if any of that is destructive, because what I can see is that the underlying image file is still linear raw. But it does affect the way it's displayed in different software.

So is it possible to cut out any variables and record a clip similar to this (especially with the clipping due to the sun hitting the window frame), but set to the Atomos recommended settings of linear/Sigma gamut for the camera output gamma/gamut on the Ninja V, and with the monitoring mode set to native? I've queued up the relevant part in the video below.

What is also not clear to me is, were you able to monitor the image in Vlog/Vgamut by choosing that on the Ninja V? In which case, why also choose to add PQ as monitoring mode on top of that? Having said that, my understanding is that it's not possible to monitor the Sigma fp PRR image in another camera's log format, only in some HDR formats like PQ. So maybe you can only monitor in PQ, but can save with vlog/vgamut embedded for when opening on your Mac.

 

[OleB]

27 minutes ago, Llaasseerr said:

So I took a look at this, and it does look promising as far as where the highlights have been placed in the Ninja V recording. I noticed in the metadata that the gamut and log curve have been set to Vlog/Vgamut, and the monitoring mode is set to PQ. Now I don't know if any of that is destructive, because what I can see is that the underlying image file is still linear raw. But it does affect the way it's displayed in different software.

So is it possible to cut out any variables and record a clip similar to this (especially with the clipping due to the sun hitting the window frame), but set to the Atomos recommended settings of linear/Sigma gamut for the camera output gamma/gamut on the Ninja V, and with the monitoring mode set to native? I've queued up the relevant part in the video below.

What is also not clear to me is, were you able to monitor the image in Vlog/Vgamut by choosing that on the Ninja V? In which case, why also choose to add PQ as monitoring mode on top of that? Having said that, my understanding is that it's not possible to monitor the Sigma fp PRR image in another camera's log format, only in some HDR formats like PQ. So maybe you can only monitor in PQ, but can save with vlog/vgamut embedded for when opening on your Mac.

 

Actually you cannot change the settings at all, in the Atomos they look like this.

Native monitoring looks a lot like LOG, but false colors are not working. However a RAW record should always be the same, no matter what you choose to monitor the picture with.

[Owlgreen]

3 hours ago, Llaasseerr said:

Yeah, I don't think Sigma really thought through the colour science aspect at all. So using the settings for a completely different camera is only ever going to be a workaround. Not to say you can't get a pleasing result, but it's not a professional solution. A good counterpoint example is the Digital Bolex. When it came out, there also was not an established workflow or monitoring method for the DNGs and they ended up recommending using the BMD log/color space. However, they did eventually develop a log profile for monitoring over HDMI and they also fleshed out how to accurately interpret the DNGs in a way that was true to the camera, plus they published a white paper. That's really what Sigma needs to do for the next model, or retroactively for the fp.

Is it within the realm of possibility that Sigma developed the FP with the BMD Film Gen 1 colorspace and gamma in mind from the start? BMD colorspace & BMD Film gamma in the Camera Raw tab is giving me by far the best results out of everything else I've tried. If it is a fluke that it works so well, then so be it. But it works and they recommend it, so maybe it's not a fluke. 

[Owlgreen]

3 hours ago, Llaasseerr said:

It looks like you could shoot a clip with a grid or checkerboard by walking around it a bit to get some parallax and then 3D track that in the Fusion tab with the 3D tracker node. As part of the track it will calculate a lens distortion model+values that can be plugged into the Lens Distortion node, or maybe it will auto generate a Lens Distortion node with the correct settings already. I haven't used Fusion, but it seems to mirror the process in Nuke.

Thank you, I will have to give that a try.

[Ryan Earl]

10 minutes ago, Owlgreen said:

Is it within the realm of possibility that Sigma developed the FP with the BMD Film Gen 1 colorspace and gamma in mind from the start? BMD colorspace & BMD Film gamma in the Camera Raw tab is giving me by far the best results out of everything else I've tried. If it is a fluke that it works so well, then so be it. But it works and they recommend it, so maybe it's not a fluke. 

If you're working in the color mode 'off' setting as they recommend then BMD color and gamma are fine.  I think it is giving you the intended look. 

If you recorded in anything other than color mode 'off.' For example you recorded in DNG but had 'portrait' as the profile set,  and you want what I think is the more accurate color, then an ACES project might be a better fit.

If you record to anything but color mode 'off' like standard or portrait and decode as BMD color and gamma you will get the same result I think as if you had recorded in 'off.'  But interestingly you can see the primaries shift if you decode to REC709 or P3-D60 with the same clip.

[Llaasseerr]

1 hour ago, OleB said:

Actually you cannot change the settings at all, in the Atomos they look like this.

Native monitoring looks a lot like LOG, but false colors are not working. However a RAW record should always be the same, no matter what you choose to monitor the picture with.

Ok, thanks for confirming that. The difference then would be the PQ vs native for the monitoring mode, but I assume that would not affect the image anyway. For some reason the file I downloaded is saying that the intermediate log curve (oetf) and gamut are Vlog/Vgamut. But ultimately, I think the image is linear gamma/sensor native gamut, because the Vlog reference is just in the metadata.

So in that case, assuming accuracy the highlights are clipping at 10.2 as a linear value at ISO 800, which from what I understand form what you said, is ISO 100 pushed 3 stops. So this is only a bit lower than where Sony cams typically clip with Slog3 recordings (11.7).

Theoretically, if the highlights clipped at at ~3.5 to 5 as a linear value in an ISO 100 image, then if you pushed it +3 stops then the max value would be somewhere between ~28-40. So I'm not sure if it would be better to try and manually cheat with a -3 ND and shoot at ISO 100 instead. Just thinking out loud though.

[Llaasseerr]

18 minutes ago, Owlgreen said:

Is it within the realm of possibility that Sigma developed the FP with the BMD Film Gen 1 colorspace and gamma in mind from the start? BMD colorspace & BMD Film gamma in the Camera Raw tab is giving me by far the best results out of everything else I've tried. If it is a fluke that it works so well, then so be it. But it works and they recommend it, so maybe it's not a fluke. 

No

[Ryan Earl]

26 minutes ago, Owlgreen said:

BMD colorspace & BMD Film gamma in the Camera Raw tab is giving me by far the best results out of everything else I've tried.

 

7 minutes ago, Llaasseerr said:

No

 

Another way to look at it is to use DaVinci YRGB color managed in your project settings and record the same scene with color mode 'off' and one with 'standard.  Then bring them both into a timeline and with those settings DaVinci handles the decode so it's grayed out in your raw tab.

You'll see that they are different even though both were recorded as cDNG.  So there must be different metadata.

 

It's almost like Sigma saw what the DNGs looked like decoding to BMD film in Resolve and went backwards to the camera and created color mode 'off' and the BRAW output to match.  So maybe it's more like an intentional workaround or hack.

 

[OleB]

5 minutes ago, Llaasseerr said:

Ok, thanks for confirming that. The difference then would be the PQ vs native for the monitoring mode, but I assume that would not affect the image anyway. For some reason the file I downloaded is saying that the intermediate log curve (oetf) and gamut are Vlog/Vgamut. But ultimately, I think the image is linear gamma/sensor native gamut, because the Vlog reference is just in the metadata.

So in that case, assuming accuracy the highlights are clipping at 10.2 as a linear value at ISO 800, which from what I understand form what you said, is ISO 100 pushed 3 stops. So this is only a bit lower than where Sony cams typically clip with Slog3 recordings (11.7).

Theoretically, if the highlights clipped at at ~3.5 to 5 as a linear value in an ISO 100 image, then if you pushed it +3 stops then the max value would be somewhere between ~28-40. So I'm not sure if it would be better to try and manually cheat with a -3 ND and shoot at ISO 100 instead. Just thinking out loud though.

Actually the result for ISO 100 and ISO 800 settings is exactly the same. False colors are not changing at all so if you expose as per that, all is identical. They first do so if you go one step higher than ISO 800. Only thing you have to consider in FCPX is that if you directly shoot in ISO 100 you can leave everything as it is, if you shoot in ISO 800 and want to bring back the picture, because in FCPX it will look blown of course (being as you said ISO 100 pushed 3 stops), you can either select manual ISO 100 or just dial down the highlights. By now I prefer the later way. 

I decided to take the ISO 800 and upwards approach, because there the false colors are accurate and additionally the screen preview is at least workable. 

[Owlgreen]

7 minutes ago, Ryan Earl said:

 

 

Another way to look at it is to use DaVinci YRGB color managed in your project settings and record the same scene with color mode 'off' and one with 'standard.  Then bring them both into a timeline and with those settings DaVinci handles the decode so it's grayed out in your raw tab.

You'll see that they are different even though both were recorded as cDNG.  So there must be different metadata.

 

It's almost like Sigma saw what the DNGs looked like decoding to BMD film in Resolve and went backwards to the camera and created color mode 'off' and the BRAW output to match.  So maybe it's more like an intentional workaround or hack.

 

This the best theory I've heard so far. I had no idea that color-mode "off" affected the cDNGs. I figured it would only affect JPEGs. I used it from day one with the camera just trying to make monitoring a little bit easier. I think Sigma would look silly if anyone in an official capacity put out list of suggested settings which were less than ideal, let alone "ruined the color" coming out of this thing, as some people have suggested. I think, as you're suggesting, they reverse engineered BMD Film Gen 1 and made it all line up. I'm running Davinci YRGB, BMD/BMD Film in Camera Raw, ACES timeline, Rec 2020 PQ output, and getting the best, most accurate-to-my-eye color I've ever seen.

[Llaasseerr]

Quote

 

It's almost like Sigma saw what the DNGs looked like decoding to BMD film in Resolve and went backwards to the camera and created color mode 'off' and the BRAW output to match.  So maybe it's more like an intentional workaround or hack.

 

 

It's more simple than that. If you look at a DNG image with the "OFF" profile (I could it "none" before by mistake) in DNG Profile Editor, it's visually very close to a similar mov shot with the "OFF" profile. I'm basing that on some comparison images uploaded a few years ago on this forum.

So really, all they did was turn off any image processing and add a Rec709 or sRGB or 2.2 gamma to a linear image and then baked that into the internal .mov files for the "OFF" profile.

All BMD have done with offering to view as BMD FIlm is they've allowed a direct translation to their log curve from the RAW tab. But you can transform to any log curve/gamut with an IDT predictably with an ACES project.

Admittedly I was not aware that the DNGs looked different when the profile is not set to "off" - how so?

[Llaasseerr]

14 minutes ago, Owlgreen said:

This the best theory I've heard so far. I had no idea that color-mode "off" affected the cDNGs. I figured it would only affect JPEGs. I used it from day one with the camera just trying to make monitoring a little bit easier. I think Sigma would look silly if anyone in an official capacity put out list of suggested settings which were less than ideal, let alone "ruined the color" coming out of this thing, as some people have suggested. I think, as you're suggesting, they reverse engineered BMD Film Gen 1 and made it all line up. I'm running Davinci YRGB, BMD/BMD Film in Camera Raw, ACES timeline, Rec 2020 PQ output, and getting the best, most accurate-to-my-eye color I've ever seen.

I believe your criticism is directed at me, lol. I'm not saying they're ruining the colour, I'm saying that they did not have a workflow as to how to monitor and develop the DNG output.

 

[Owlgreen]

8 minutes ago, Llaasseerr said:

I believe your criticism is directed at me, lol. I'm not saying they're ruining the colour, I'm saying that they did not have a workflow as to how to monitor and develop the DNG output.

 

It really wasn't. I've seen the words "ruin the color" multiple times on multiple forums in reference to using anything other than P3 D60 and a CST. If you didn't say those words then my comment didn't have anything to do with you.