Sigma Fp review and interview / Cinema DNG RAW

[Llaasseerr]

19 hours ago, paulinventome said:

Yes, drop them a line and ask. That's what i mean. Doesn't have to be log, the values they choose can match the data better - it could be a log with an s curve to distribute mid tones better. We will never see that curve, we will only ever see the results after the curve.

Whilst the DAC is 14 bit i am pretty sure that the mode they are running the sensor in is 12 bit output for motion. And a 10 bit DNG with a linearisation table would hold everything a 12 bit linear file could - i see no reason for a 12 bit option at all.

I think 4096 across should be an option though, even if it's scope (4096 x 1716) or 2:1 (netflix style 4096 x 2048) - the overall data rate would be roughly the same as UHD.

 

I think a couple of wish list items. Yes, a user LUT to output baked formats would be useful in some cases.

But tools to expose for RAW better - i'm still trying to wrap my head around the zebra at 100% and what that actually means.

cheers
Paul

I'm glad they're adding log, but I would only use it for monitoring raw recording. For that, it's crucial. The log image with LUT will then match the RAW image with LUT in Resolve (different input but same output image). 

So as long as:

- They publish the log curve and wide gamut they are using. They need a conventional Cineon/AlexaLogC/ACEScct type of log curve that will hold all the highlight information of the raw sensor.

- It can send a log signal over HDMI so that you can record DNG raw and monitor with a lut on the HDMI log image. If it's sending out raw over HDMI that's quite cool, but as far as monitoring,  you are limited to the Atomos Ninja V vs. every other EVF or external monitor on the market that allows a custom LUT. 

 

As for exposing raw, the only two things you need to think about are:

1. Expose with a grey card and a lightmeter like you are exposing film. You can also use false colour and a grey card but just make sure you're aware of what gamma setting the false colour is expecting, or make your own false colour LUT.

2. Check where the highlights are clipping. If you need to protect the highlights further, then underexpose by 1 or two stops and push by the same amount in post. Use Neat Video to clean up the noise floor if necessary.

Zebras are for a video world. They can be semi relevant for checking highlights in log since it puts everything in a 0-1 range. Again, we need log output for monitoring and if for example shooting for ACES we can put a log to ACES rrt/odt LUT on the camera monitor/EVF and see how the full dynamic range of the highlights are rolling off. Then get the exact same result on the ingested DNG raw images to ACES in Resolve.

 

23 hours ago, paulinventome said:

Nice find Lars.

Log profile is utterly irrelevant on this camera and it won't expand the dynamic range. You have the RAW output - you will never get better than that. This is the whole point of this camera...

RAW via HDMI is a nice idea.

cheers
Paul

Log for monitoring raw recording is crucial as it allows any Chinese 8 bit monitor with custom LUT option to display the full raw image dynamic range and get a very close match to what you will see in Resolve with your beautiful DNGs - as long as you have your technical LUTs set up correctly.

Published log and gamut is a MUST though. Sigma, please do a white paper documenting this. This way, we can do a direct correlation with the linear raw image. And allow sending log over HDMI while recording raw.

[paulinventome]

16 minutes ago, Llaasseerr said:

- It can send a log signal over HDMI so that you can record DNG raw and monitor with a lut on the HDMI log image. If it's sending out raw over HDMI that's quite cool, but as far as monitoring,  you are limited to the Atomos Ninja V vs. every other EVF or external monitor on the market that allows a custom LUT. 

 

As for exposing raw, the only two things you need to think about are:

1. Expose with a grey card and a lightmeter like you are exposing film. You can also use false colour and a grey card but just make sure you're aware of what gamma setting the false colour is expecting, or make your own false colour LUT.

 

 

As i understand if atomos will be recording RAW over HDMI then the HDMI signal will be data, not image. The Atomos recorder would then debayer and display with whatever tools they have onboard for that. So monitoring whilst recording would be a function of the display, not camera? (Maybe the camera LCD would display anyway). It's basically just dumping data down the HDMI connection rather than USB. This would be super useful. 

I would never monitor in log, although i don't think you're saying that? The idea of monitoring through a LUT is great, in the past i've generated LUTs including false colouring for specific exposure regions.

But monitoring RAW is more difficult - what i really want is, no matter what the image is showing, i want to see when each of the RAW channels has clipped, simple as that. Then i can make a judgement based off that.

With limited bit depth and container sizes the whole ETTR becomes an issue again. If it was 16 bit RAW then sure, do the right thing and expose for mid grey and give the editor a break but i feel with this camera that highlight exposure becomes important again.

The enclosed screenshot show the difference with highlight reconstruction on and off. I knew that not all the raw channels had clipped so was pretty confident about this. If this was a log format then you'd be dealing with baked in white balance and you would not get these highlights. So for monitoring, happy to have an image to focus by, but with the knowledge of what the actual sensor is seeing.

The image is stress testing, i'm side by siding with a Red Epic-W so i can find the best mid ground settings between them. The fp is a fantastic little camera, no doubt. I'm having issues with colourspaces though (workflow i think) and the range is not anywhere close to the Red. But for its size and cost it's amazing!

The ability to do this reconstruction is scene dependant. You basically need to have a spread of channels where one or two may have clipped but one hasn't. Skies are great for this as red usually doesn't clip so much.

Some cameras employ a trick where one of the G pixels is less sensitive too.

cheers
Paul

 

 

 

[Llaasseerr]

32 minutes ago, paulinventome said:

As i understand if atomos will be recording RAW over HDMI then the HDMI signal will be data, not image. The Atomos recorder would then debayer and display with whatever tools they have onboard for that. So monitoring whilst recording would be a function of the display, not camera? (Maybe the camera LCD would display anyway). It's basically just dumping data down the HDMI connection rather than USB. This would be super useful. 

I would never monitor in log, although i don't think you're saying that? The idea of monitoring through a LUT is great, in the past i've generated LUTs including false colouring for specific exposure regions.

But monitoring RAW is more difficult - what i really want is, no matter what the image is showing, i want to see when each of the RAW channels has clipped, simple as that. Then i can make a judgement based off that.

With limited bit depth and container sizes the whole ETTR becomes an issue again. If it was 16 bit RAW then sure, do the right thing and expose for mid grey and give the editor a break but i feel with this camera that highlight exposure becomes important again.

The enclosed screenshot show the difference with highlight reconstruction on and off. I knew that not all the raw channels had clipped so was pretty confident about this. If this was a log format then you'd be dealing with baked in white balance and you would not get these highlights. So for monitoring, happy to have an image to focus by, but with the knowledge of what the actual sensor is seeing.

The image is stress testing, i'm side by siding with a Red Epic-W so i can find the best mid ground settings between them. The fp is a fantastic little camera, no doubt. I'm having issues with colourspaces though (workflow i think) and the range is not anywhere close to the Red. But for its size and cost it's amazing!

The ability to do this reconstruction is scene dependant. You basically need to have a spread of channels where one or two may have clipped but one hasn't. Skies are great for this as red usually doesn't clip so much.

Some cameras employ a trick where one of the G pixels is less sensitive too.

cheers
Paul

 

 

 

Raw over HDMI - just force the bayer image down HDMI then debayer later. It's a neat idea but not really useful for this camera since it will record raw natively. There may be some nice advantages that become apparent later. I didn't mention it with regards to monitoring though.

What I'm saying is that to monitor raw in a practical,, usable way, you need a log image to compress the full dynamic range to a normalised space that can be sent over HDMI/SDI to any typical screen, then you add a transform from log to your final look. The final look is typically something like an Arri look lut when shooting Alexa, or ACES rrt/odt combo (they are both similar anyway). I make the LUT in Nuke or Lattice and then upload it to the monitor.

So yes to confirm, not monitoring literally in log, but send a log signal over HDMI to put the LUT on it. You have to think of log in this case as being the same as raw, but the sensor's whole dynamic range has been compressed to fit down the HDMI with no clipping, via a log transfer function. That way, you get to monitor the raw image. Sure, some things are baked in. But you get the dynamic range. You get a very good, close representation of what you will look at in Resolve with the raw images later.

What you are asking for, to see the clipping point of the raw channels, you can do that by monitoring a log signal since the Sigma log curve will encompass the entire dynamic range of the sensor. However there is a neat view mode on the Digital Bolex that is just the output of the bayer sensor, and you can clearly see where it's clipping the highlights and adjust the exposure accordingly. That would be nice to add. It's actually very similar to what ProRes raw is doing - just outputting the bayer image over HDMI.

Yes the log monitoring approach doesn't account for extra white balance or highlight construction flexibility with raw. That's a nice little bonus you get to play with in Resolve.

 

 

 

[Lars Steenhoff]

If its hdmi to the  ninja it will be prores raw, which is partially debayered as far as I know.

Not real raw like the cinema dng

[mechanicalEYE]

 

[paulinventome]

21 hours ago, Llaasseerr said:

What you are asking for, to see the clipping point of the raw channels, you can do that by monitoring a log signal since the Sigma log curve will encompass the entire dynamic range of the sensor. However there is a neat view mode on the Digital Bolex that is just the output of the bayer sensor, and you can clearly see where it's clipping the highlights and adjust the exposure accordingly. That would be nice to add. It's actually very similar to what ProRes raw is doing - just outputting the bayer image over HDMI.

Red uses traffic light warnings that come on when that channel is clipped. That's generally all i want. I usually don't want to monitor the entire signal i would rather a contrasty image to focus and compose with. But a user LUT would give us both.

The problem with monitoring a log signal is that it has been white balanced so therefore no RAW clipping info. If it wasn't white balanced then it would be mostly green! 

That's the issue - i would like RAW indicators, not after they've been matrixed.

I don't know enough about ProRes RAW, i didn't think it was part debayered, just BRAW that was. Just using the HDMI as a digital transport to a recorder that can not only record the DNG data, but debayer for remote display makes sense. I believe the HDMI bandwidth is plenty high enough to take any data off the camera.

cheers
Paul

[Lars Steenhoff]

I'm not sure about pro res raw, it could be just compressed and not debayered, but in the end I will stick with cdng.

[paulinventome]

A bit more info for those interested.

Firstly, as expected, setting white balance in camera does not affect the RAW file. There have been cameras that have baked white balance before, the Sony FS700 for one used to do that (or the FS7, one of them did). But that does not happen here.

Secondly i'm enclosing the image of the linearisation curve in 8 bit. It's a good curve, it's not log but redistributes the values in a way that makes sense.

Thirdly. Anyone worked out WTF is going on with focus magnification? So in cine mode, i can assign the AEL button to zoom. But how do i move around the screen to focus on different areas. I would have thought the control ring would (like on any other camera). It is possible - you can do it through elevntybillion key presses. Also pressing the touch screen would make sense but that just puts the auto focus points up... I must be missing something here!

cheers
Paul

 

[Brian Williams]

1 hour ago, paulinventome said:

Thirdly. Anyone worked out WTF is going on with focus magnification? So in cine mode, i can assign the AEL button to zoom. But how do i move around the screen to focus on different areas. I would have thought the control ring would (like on any other camera). It is possible - you can do it through elevntybillion key presses. Also pressing the touch screen would make sense but that just puts the auto focus points up... I must be missing something here!

cheers
Paul

I don't have mine with me at the moment to check this, but I'm pretty sure you can't, you have to set the focus point first, then zoom in, and once there you can't change the position until you zoom back out and move the focus point. I'll confirm this tonight.

Which sucks, yes.

[Lars Steenhoff]

You also cannot use the zoom while recording, I would love to have this, sigma learn from sony and fuji

[paulinventome]

2 hours ago, Brian Williams said:

I don't have mine with me at the moment to check this, but I'm pretty sure you can't, you have to set the focus point first, then zoom in, and once there you can't change the position until you zoom back out and move the focus point. I'll confirm this tonight.

 

But there's no quick way to set that focus point is there? It's a multiple key press to get to a point to move the reticule around and then that spot stays. Very frustrating when you can't really focus off the screen very well.

I hope we can get the way this works changed a bit!

cheers
Paul

[MikhailA]

This was shot in 1080p .  very noticeable aliasing  artifacts   0:39  1:35

[nathlas]

 

Sigma confirms LOG picture profile, Raw over HDMI coming to its fp camera via firmware update

[Lars Steenhoff]

 

[Anaconda_]

I'm so torn between this and X-T3 for family videos, photos and grabcam.

My sensible side says XT3 for great photos, AF 60p - but my bigger, more impulsive side is saying FP FP FP FP FP. 

[Lars Steenhoff]

Go for the fuji, then buy the fp next year when the firmware has had more time to mature.

[Andrew Reid]

3 hours ago, Anaconda_ said:

I'm so torn between this and X-T3 for family videos, photos and grabcam.

My sensible side says XT3 for great photos, AF 60p - but my bigger, more impulsive side is saying FP FP FP FP FP. 

How about the X-H1?

[Anaconda_]

36 minutes ago, Andrew Reid said:

How about the X-H1?

It's on the radar, but aside from IBIS I feel like the XT30 has the upper hand for personal usage...

That said, I am to-and-fro-ing between the 3 Fuji's. This week I can get XT30 and kit 15-45 for 600e, which seems too good to be true... or swap the lens out for 35mm f2 for 860e - but then its worth springing the extra for the XT3 35mm f2 for 1222 euros... And so the terrible cycle continues.

 

 

[thebrothersthre3]

1 hour ago, Anaconda_ said:

It's on the radar, but aside from IBIS I feel like the XT30 has the upper hand for personal usage...

That said, I am to-and-fro-ing between the 3 Fuji's. This week I can get XT30 and kit 15-45 for 600e, which seems too good to be true... or swap the lens out for 35mm f2 for 860e - but then its worth springing the extra for the XT3 35mm f2 for 1222 euros... And so the terrible cycle continues.

 

 

Used XT30's are going for a crazy low price right now around $700 + a used 18-35 is only $250-$270. If you are willing to go used. 

[Brian Williams]

7 hours ago, Anaconda_ said:

I'm so torn between this and X-T3 for family videos, photos and grabcam.

My sensible side says XT3 for great photos, AF 60p - but my bigger, more impulsive side is saying FP FP FP FP FP. 

Having recently gone from X-T3 to the FP, and the fact that I’m on holiday in Denmark with my family at the moment with the FP, I’d say go for the X-T3.

Not to say I’m disappointed with the FP at all, but the fact that I’m having to edit all the day’s footage each night in Resolve so that I can clear out the T5 for the next day’s footage isn’t the most convenient. And having the T5 strapped to the camera also takes away from the compactness of the camera. And I’d even be willing to shoot with the internal 8bit for the sake of losing the SSD, but, damn, fast sd cards are so much more expensive for way less capacity than the T5.

Plus, for stills, at night, the FP’s AF isn’t ideal.