SIGMA FP with ProRes RAW and BRAW !

[Ryan Earl]

14 hours ago, Llaasseerr said:

For the most flexibility, you can just use an ACES project to import the DNG files to Resolve, then export to a format you're familiar with (like Alexa LogC/Alexa wide gamut) and use in a non-ACES project. Depending on how the metadata is written in the ML raw files, it should work pretty well but obviously it's good to compare how well they work within the MLV app as well

I'm not too familiar with ACES, I've just tried these project settings and all the highlights seem available, lift gamma gain tools are responding great, color seems good:

How would you suggest setting it up for ARRI log C?

[Llaasseerr]

6 hours ago, Ryan Earl said:

I've been importing the cDNG through SlimRAW as 3:1 and they playback much better and I'm able to upscale slightly to DCI 4K for monitoring / exporting. 

 

I should clarify that I think when working in CDNG and 'naked' without BRAW or ProRes RAW it does appear to show the correct false color values on the rear lcd screen with the new firmware, but that false color reading is in conflict with the waveform, zebras and preview. 

Been using SlimRaw with my Digital Bolex for some time now!

Glad to hear the false color works with DNGs when the camera is 'naked' - tbh, that would be my main user application. I think someone here - perhaps you - mentioned that it reads the value directly off the sensor regardless of the picture profile set, which sounds nice. 

 

[Llaasseerr]

6 hours ago, Ryan Earl said:

I'm not too familiar with ACES, I've just tried these project settings and all the highlights seem available, lift gamma gain tools are responding great, color seems good:

How would you suggest setting it up for ARRI log C?

Yes if you wanted to stay in ACES then those settings are fine.

If you wanted to use Arri LogC/AWG, I suggest rendering it out which works well if you render something like a Prores 4444 file. Then you can bring it into a new non-ACES project afterwards if you want, because the DNGs will have been correctly interpreted by the DNG IDT within the ACES project.

If reusing in a new ACES project or the same ACES project, then when importing use the Alexa IDT which I think is also called "Arri LogC EI800 AWG".

First set the Output Transform to "no output transform" and apply an ACES Transform node to the footage, where the input is "no input transform" and the output is "Arri LogC EI800 AWG". Also set the gamut compress type to "reference gamut compress". Then render.

Also note that you can create your own ACES workflow in a non-ACES project by using the ACES Transform node. But this doesn't work for importing DNGs because the IDT is only available in an ACES project. So I do that in a dedicated ACES project as a first step.

 

[Llaasseerr]

@OleB is there any chance you can upload a 4k DCI ProRes Raw clip? Preferably one with clipped highlights shot at what you think is the best ISO. 

I'd be interested to try developing it in Assimilate Play Pro which, in my experience, is able to handle ProRes Raw import as well as Resolve can handle DNGs.

I saw this test on youtube shot at ISO 3200 with PRR and I must say, it looks super clean which suggests that the exposure could really be pushed with an ND.

 

[webrunner5]

Looks to me they are hiding a lot of the noise using de sharpen. And if you could zoom into the background I bet it is pretty noisy as well. But yeah looks pretty clean.

[TomTheDP]

Just purchased this camera, coming tomorrow. I am really interested to see how it can match to the ARRI alexa.

[Llaasseerr]

45 minutes ago, webrunner5 said:

Looks to me they are hiding a lot of the noise using de sharpen. And if you could zoom into the background I bet it is pretty noisy as well. But yeah looks pretty clean.

There's the whole issue with uploading to youtube as well, so yes it's better to look at the full quality frames to assess sensor noise. I don't even know if youtube applies a denoise before compressing the hell out of the image, but it would make sense if it did.

[Llaasseerr]

1 minute ago, TomTheDP said:

Just purchased this camera, coming tomorrow. I am really interested to see how it can match to the ARRI alexa.

What do you think of the loupe vs the side viewfinder? I think I might have a soft spot for the loupe.

[webrunner5]

Yeah, I am sure it looks better on the computer than when YouTube did their "thing". 

[TomTheDP]

18 minutes ago, Llaasseerr said:

There's the whole issue with uploading to youtube as well, so yes it's better to look at the full quality frames to assess sensor noise. I don't even know if youtube applies a denoise before compressing the hell out of the image, but it would make sense if it did.

I think the compression acts as a denoiser in someway. But overall that footage looks fantastic. The camera has dual native ISO at 3200 so it should look very clean.

 

17 minutes ago, Llaasseerr said:

What do you think of the loupe vs the side viewfinder? I think I might have a soft spot for the loupe.

I will probably get the side viewfinder eventually. I am not quite sure if it offers a full hdmi out, which could be beneficial.

I think I will buy the tilt screen modification.
 

 

[Llaasseerr]

10 minutes ago, TomTheDP said:

I think the compression acts as a denoiser in someway. But overall that footage looks fantastic. The camera has dual native ISO at 3200 so it should look very clean.

 

 

On the subject of how this compares to an Alexa, obviously it would be closest to the LF. Purely based on image, my hot take is the Alexa has 3.5-4 stops more DR in the highlights and better rolling shutter, but that given the low noise of this camera it could be underexposed to make up for that to some extent. Easily by 2 stops.

[TomTheDP]

1 hour ago, Llaasseerr said:

On the subject of how this compares to an Alexa, obviously it would be closest to the LF. Purely based on image, my hot take is the Alexa has 3.5-4 stops more DR in the highlights and better rolling shutter, but that given the low noise of this camera it could be underexposed to make up for that to some extent. Easily by 2 stops.

Yeah I meant more in terms of color. I'd imagine the dynamic range isn't too far off. The Alexa has a full 6 stops in the highlights. Its harder to judge shadows on the Alexa, it gets noisy quickly but its pleasant noise and information is still there along with color accuracy. I would say 3 stops under and 6 over on the Alexa though.

The Alexa is just so easy to get a good image out of. From what I have seen Sigma FP colors are pretty true to life, which should mean they aren't far off from ARRI. I am playing with some test footage right now, it looks really lovely though when over exposed it's not pretty. On the plus side the SlimRAW program is super easy to use and fast. Will make storing files really easy with the 7-1 option.

It's unfortunate that monitoring the RAW is kind of a pain. Another nice thing about the Alexa is the zero lag SDI output that will also output a 100% accurate REC709 or log signal to a monitor. It's so nice for client or anything where there is an on set producer or director.

[OleB]

6 hours ago, Llaasseerr said:

@OleB is there any chance you can upload a 4k DCI ProRes Raw clip? Preferably one with clipped highlights shot at what you think is the best ISO. 

I'd be interested to try developing it in Assimilate Play Pro which, in my experience, is able to handle ProRes Raw import as well as Resolve can handle DNGs.

I saw this test on youtube shot at ISO 3200 with PRR and I must say, it looks super clean which suggests that the exposure could really be pushed with an ND.

 

Sure, that should be possible. Can you be a little more precise what would be of help? In regards to ISO, I usually use 800 and 3200 for the both native ISO values and try to avoid what is in between if possible.

For the 3200 value I suppose lighting up a match in completely dark room would be an amazing test to see if there is noise, no?

Am not sure if I get your approach quite right yet with underexposing to have more highlights. Take this example, bright blue sky, white clouds. I expose with the false colors so that the white clouds retain details and are not clipping the sensor. What would be the benefit of underexposing them? Without clipping all details are already present, or do I miss something? 

[kye]

6 hours ago, TomTheDP said:

Just purchased this camera, coming tomorrow. I am really interested to see how it can match to the ARRI alexa.

Keen to hear your thoughts on the camera, image, and this rather strange exposure behaviour...

1 hour ago, OleB said:

For the 3200 value I suppose lighting up a match in completely dark room would be an amazing test to see if there is noise, no?

You mean a test like this?

 

[Llaasseerr]

3 hours ago, OleB said:

Sure, that should be possible. Can you be a little more precise what would be of help? In regards to ISO, I usually use 800 and 3200 for the both native ISO values and try to avoid what is in between if possible.

For the 3200 value I suppose lighting up a match in completely dark room would be an amazing test to see if there is noise, no?

Am not sure if I get your approach quite right yet with underexposing to have more highlights. Take this example, bright blue sky, white clouds. I expose with the false colors so that the white clouds retain details and are not clipping the sensor. What would be the benefit of underexposing them? Without clipping all details are already present, or do I miss something? 

 

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.

[Llaasseerr]

6 hours ago, TomTheDP said:

Yeah I meant more in terms of color. I'd imagine the dynamic range isn't too far off. The Alexa has a full 6 stops in the highlights. Its harder to judge shadows on the Alexa, it gets noisy quickly but its pleasant noise and information is still there along with color accuracy. I would say 3 stops under and 6 over on the Alexa though.

The Alexa is just so easy to get a good image out of. From what I have seen Sigma FP colors are pretty true to life, which should mean they aren't far off from ARRI. I am playing with some test footage right now, it looks really lovely though when over exposed it's not pretty. On the plus side the SlimRAW program is super easy to use and fast. Will make storing files really easy with the 7-1 option.

It's unfortunate that monitoring the RAW is kind of a pain. Another nice thing about the Alexa is the zero lag SDI output that will also output a 100% accurate REC709 or log signal to a monitor. It's so nice for client or anything where there is an on set producer or director.

The Alexa is about 8 1/3 stops over middle grey, it's a monster. In linear values, where grey is 0.18 the Alexa clips at about ~55-65. Agreed, it gets noisy quickly compared to a camera like the fp, so in my mind with the fp there's room to hack shifting the entire DR to the right because I can live with a bit of noise as long as it looks pretty organic.

 I don't get why all the smaller cams are obsessed with low noise floor at the expense of highlight DR. One of my pet theories is that the increased sensor voltage for highlgihts uses more power so they focus on clean shadows instead.

And yes, the monitoring is sorted. That is severely lacking on the fp.

[kye]

I suspect that this will derail the conversation completely but I'm going to ask it anyway...   if you're shooting RAW then does middle-grey even matter?

It definitely does when shooting LOG, as many LOG formats allocated less bit-depth to the brightest and darkest stops so you really did want to put your skintones in the middle where there was better IQ, but considering that Linear RAW gives the most bit-depth to the highlights and the least to the shadows, does the concept even make sense any more?

I understand that if you're working with an editor/colourist then you want to expose things so that you can put on a display LUT for the editor and the colourist has a good starting point, but if you're trying to eek out the most quality and are willing to change exposure between shots, why wouldn't you just ETTR?

[kye]

Or does BRAW / Prores RAW also allocate more bit-depth / bandwidth to the middle part of the DR?

[hyalinejim]

2 hours ago, kye said:

if you're shooting RAW then does middle-grey even matter

One valid reason not to ETTR on every shot is that it creates extra work in balancing exposure in post, versus exposing for middle grey where the same correction should work for each clip regardless of highlight level.

[stephen]

Would rather put a new camera in series of practical tests shooting scenes that typically shoot, rather then set expose based on some assumptions. Those assumptions may not be true. We have no idea how exactly a particular manufacture is interpreting the RAW data from a given sensor.

If we have to believe this test:

Sigma FP shooting raw video handles underexposure much better than overexposure. Some people interpret the Sigma RAW video as BM Log and then do CST (Color space transform) and claim this is the way to extract more dynamic range to the full potential of the sensor (12.7 stops). CDNG files from Sigma RAW video according to them  give lower dynamic range.

Have similar experience with Canon ML RAW video on hacked Canon 5D Mark III and Canon EOS M. There is ETTR function in the hack and multiple people advice to do ETTR in order to reduce noise when shooting at HIGH ISOs. In practice at lower ISOs (and high as well) risk of burn in highlights is quite high. Canon RAW CDNG files are handling underexpose better than overexposure. I was able to recover at one occasion 4 or 5 stops of underexposure due to forgotten VND for daylight when shooting at night. As result when shooting Canon ML RAW tend to underexpose half a stop, and almost never go for ETTR. And like the results and footage better.