Sigma Fp review and interview / Cinema DNG RAW

[Sid]

Regarding audio, I believe FP has a built-in microphone, so isn't the "proper" workflow to record scratch audio and sync up to separate audio recording anyway ?  Otherwise surely we're talking XLR type inputs....which changes the idea of the camera ?  Like a masochist, I may hold out to see what the Canon mirrorless version of 5DXMk3 is like (excellent for a price I'm sure), but common sense says to me grab the Sigma now...

[The ghost of squig]

19 hours ago, CaptainHook said:

Isn't Magic Lantern Raw/Linear? I thought it was?

Yeah, it is.

[CaptainHook]

2 hours ago, The ghost of squig said:

Yeah, it is.

What do you mean by Magic Lanterns highlight rolloff then sorry? I think I missed something.

[The ghost of squig]

48 minutes ago, CaptainHook said:

What do you mean by Magic Lanterns highlight rolloff then sorry? I think I missed something.

Lulz. I mean 'how does it compare to the 5D Mk3 with Magic Lantern'. And the Pocket 4K/6K too for that matter.

[CaptainHook]

Ah gotcha.

I'm not really directing this at you but just to anyone in general who isn't aware or wants to learn more, and I'm probably being a 'stickler for accuracy' here but obviously a sensor/camera has no inherent highlight rolloff as the sensor is linear (as close as practically possible with calibration) so highlight rolloff is mostly down to the dynamic range of the sensor, how the image is exposed and how the colourist chooses to roll off the highlights. All typical CMOS sensors will have "hard clipping" though, being linear capture devices.

I only say this because I see a few people mention 'highlight rolloff' as part of a log curve or colour science or something when in that respect it is just a by-product of the log curve optimising the dynamic range of the sensor in the container its being stored in. It's still assumed the user will create their own highlight rolloff in grading (I'm speaking just of RAW and log captures, not "profiles" or looks applied in camera intended for display on Rec.709 devices).

ARRI for example have a lot of stops above where they recommend middle grey be exposed for - due partly to their very large pixels and the large dynamic range they have - and when a log curve is calculated for mapping that dynamic range from middle grey to 940 (video white in 10bit where they map sensor saturation to in their log curves) you get a very flat curve at the top as it maps that range. When you flatten contrast that much it also appears to desaturate. I've seen some mention they believe ARRI purposely desaturate their highlights, but if they did that in processing before creating RAW files or LogC ProRes clips you wouldn't be able to inverse it correctly into linear for ACES workflows etc because processing like that is non-linear. They possibly do something like that for their LogC to Rec709 LUTs etc but people seem to attribute it to their LogC/RAW files too.

For our cameras we map sensor saturation at our "native ISO" to 940 also, but for ISO curve's above we go into "super whites" to make better use of the bit depth available especially since we deal so much with SDI output (10bit) and ProRes 422HQ is common for our customers (10bit also). ARRI says ProRes 444 (12bit) is the minimum for LogC because they don't use the full range available. We may change that in the future but the caveat would also be you would need to use 12bit for best results.

In theory you could expose a 10 stop camera/sensor so that you place middle grey at the second bottom stop, giving you 8 stops to create a very gentle highlight rolloff. You would just have VERY little range for the shadows. ?

So long story short, the question I would suggest people ask is 'what is the dynamic range like compared to other cameras' as that will really tell you what kind of highlight roll off YOU (the user) can create for your preference with how you like to expose given the amount of shadow information you like to retain, tolerance for noise, etc.

[paulinventome]

23 hours ago, Sid said:

Regarding audio, I believe FP has a built-in microphone, so isn't the "proper" workflow to record scratch audio and sync up to separate audio recording anyway ?  Otherwise surely we're talking XLR type inputs....which changes the idea of the camera ?  Like a masochist, I may hold out to see what the Canon mirrorless version of 5DXMk3 is like (excellent for a price I'm sure), but common sense says to me grab the Sigma now...

There's a 3.5mm jack for mic input. Normally you'd stick a tentacle or similar in there for time code sync.There's no headphone though but if you can get timecode into it then that makes it very easy

cheers
Paul

[Brian Williams]

I’m excited!

[kye]

 

[Brian Williams]

Its not great, but if anyone wants this, here's a short 4K 12-bit DNG sequence I shot tonight-

https://www.dropbox.com/s/3blhq57dr1ql866/A001_014.zip?dl=0

[ZooMoo]

53 minutes ago, Brian Williams said:

Its not great, but if anyone wants this, here's a short 4K 12-bit DNG sequence I shot tonight-

https://www.dropbox.com/s/3blhq57dr1ql866/A001_014.zip?dl=0

Thank you! 

[Deadcode]

1 hour ago, Brian Williams said:

Its not great, but if anyone wants this, here's a short 4K 12-bit DNG sequence I shot tonight-

https://www.dropbox.com/s/3blhq57dr1ql866/A001_014.zip?dl=0

Thank you for sharing!

It's always nice to work with RAW.

However am i spoiled by todays in-camera noise reduction or this is noisy for an ISO1600 (underexposed 1EV so ISO3200) shot?

/TNR and Spatial NR is already applied/

[thebrothersthre3]

2 hours ago, Brian Williams said:

Its not great, but if anyone wants this, here's a short 4K 12-bit DNG sequence I shot tonight-

https://www.dropbox.com/s/3blhq57dr1ql866/A001_014.zip?dl=0

Gosh that is a nice image. 

[jase]

Can any of the owners comment on the amount of crop that is applied as soon as EIS is activated? I am wondering whether with activated EIS (small) APS-C lenses might be an option... Leica has some smaller TL lenses that look promising (and expensive...).

[BTM_Pix]

51 minutes ago, jase said:

Leica has some smaller TL lenses that look promising (and expensive...).

They are pretty good (particularly the 23mm and 11-23mm) but ridiculously expensive.

I have the 18-56mm and even as a used "bargain" it was the better part of £700.

£700 for a used f/3.5–5.6 zoom lens.

Its a good f/3.5–5.6 zoom lens of course but even so.

Sigma have their own APS-C L mounts on the way so I'd definitely hang on to have a look at those before committing.

If you are looking for small then I'd recommend going down the M mount route with an adapter as you'll get full frame coverage, fast apertures and very decent prices with the 3rd party brands like Voigtlander and 7Artisans.

Manual focus of course but looking at the AF performance on those Benny Hill reboot videos posted further up the thread its not that much of a loss to me 

 

[Andrew Reid]

43 minutes ago, jase said:

Can any of the owners comment on the amount of crop that is applied as soon as EIS is activated? I am wondering whether with activated EIS (small) APS-C lenses might be an option... Leica has some smaller TL lenses that look promising (and expensive...).

The crop to my eye (not scientific) is about 1.2x or 1.3x crop in full frame mode with EIS activated. You also have an actual 4K Super 35mm crop mode as well (1.5x). You can only enable EIS in MOV 4K mode not Cinema DNG. When I use the Sigma 18-35mm F1.8 in full frame EIS mode, it still vignettes a bit in the corners at 18mm but fine at 35mm. You'd need to crop a bit more in post to get the wide end to look ok.

[Brian Williams]

Is it me or is the camera system a little wonky? Like I would assume settings wouldn’t carry over from Stills to Cine, or vice versus, but if you set AF to manual In CINE mode, then switch over to stills, I’m still MF. Same for ISO, program mode. I’d hope these things would’ve stay specific to either mode, to make it easier to switch back and forth.

[Llaasseerr]

On 10/28/2019 at 8:32 AM, cpc said:

You should be able to do the same with any intraframe codec in a container, no?

In any case, whether your intermediate is a sequence (DPX or EXR or whatever) has little to do with whether your source media is a sequence.

If you mean some kind of container with still frames inside, then yes. I'm not clear on how MXF works but I'd like it if it was the best of both worlds and just a wrapper around the DNG frames that you can right click on and then go inside. I'll agree this is all pretty old tech but I'm not as opposed to the format as others.

Personally I do think that the same general advantages I talked about with frames apply to intermediate sequences and source media as far as file handling. I'm not 100% on this, but if you record a movie then can't a couple of bad frames corrupt the whole mov file, rather than allowing you to salvage most of what was shot because it was frame based?

Quote

Are you talking source metadata or intermediate (post) metadata? The latter shouldn't be related to what your source is.

I'm talking about source metadata that is carried all the way through from shoot to ingest through post and vfx to DI. It could be matrices, CDL, lens information, etc. So if you go to an intermediate format like exr then all the footage metadata from the shoot comes along for the ride. But I'll admit that this workflow is not something that most people on this forum are considering.

Quote

It is not for one man bands only though. I've done it on a couple of indie productions where I shared dng proxies with the editor (they did edit in Resolve). I also know for at least two production houses that do work this way. But yes, bigger productions will likely promote a more traditional workflow. Yet I think film post can gain as much from utilizing raw processing controls for correction/grading as any other production, as it is in some ways more intuitive and more mathematically/physically correct than the common alternative.

That's cool. You wrote slimRAW right? I own it ?. I have a Digital Bolex and it's 100% necessary for that camera. I'm sure it will be gold for the Sigma fp. I personally don't believe it's worth the overhead of debayering raw on the timeline, but then again I haven't tried out ProRes RAW. BRaw seems lossy in the chroma channels so I'm not going there. I just feel it's better to ingest to the full dynamic range floating point RGB (EXR) or log dpx/ProRes. And I can assure you that raw processing controls are utilised on big productions, but at an ingest stage. There is always the option to go back and reprocess the raw if the debayer algorithm needs changing - or the colour temperature, but in that case the data bucket of the exr is so huge that a temperature shift to the rgb image is 99% of the time totally fine. The reality is that when you capture the whole thing to an EXR or DPX there is very little that is baked in.

As to what you are saying about grading at a raw level in a more precise way - I do agree that grading software can seem kind of slap dash in some ways that is just really odd. I personally use Nuke for things like exposure and temperature changes, and Nuke's grading nodes are much more mathematically oriented than Resolve. Not that Nuke is a good grading tool per se, but it's more suited to making precise changes. It bothers me that if a dp says "can you push this plate +1 stop" that there is no obvious go-to linear exposure control in Resolve - except in the raw controls tab. Also it's really weird the way Resolve does not allow direct colour matrix input.

On 10/28/2019 at 6:13 AM, CaptainHook said:

I would offer that for matching shots (the majority of most grading work), adjusting white balance in sensor space (or even XYZ as a fallback) and exposure in linear makes a huge difference to how well shots match and flow. I see many other colourists claim they can do just as good white balancing with the normal primaries controls, but i think if they actually spent considerable time with both approaches instead of just one they would develop a sensitivity to it that would make them rethink just how 'good' the results with primaries are. Its one area i think photographers experienced with dialing in white balance in RAW files develop that sensitivity and eye to how it looks when white balance is transformed more accurately - more so than those in the motion image world who still aren't used to it.

I've been a fan of Ian Vertovec from Light Iron for quite a few years, and I was not surprised to learn recently that he likes to do basic adjustments in linear because there was something in his work that stood out to me (including his eye/talent/skill/experience of course).

Mate, you're preaching to the choir. I'm 100% with you on exposure in linear - Then why doesn't Resolve offer a linear exposure adjustment tool except on the raw tab? This baffles me. You work for Black Magic right?

 I'm not actually a colorist though. I mainly use Nuke (all-linear all the time) and am reluctantly learning Resolve. For me, going to and from XYZ to do some comp operation is a lot more intuitive than it is in Resolve. So that concept is not foreign to me either. I tech proof things in Nuke before trying to rebuild them with Resolve nodes.

I appreciate that Resolve 16 added the colour temperature adjustment node, but I do agree about white balance in raw as being the best way to do it. A friend who worked on Rogue 1 told me the DP Greig Fraser apparently shot the Alexa 65 all at 6500k temperature since it was all RAW capture, and then of course that can be adjusted on raw ingest. He may be wrong about this, but this is what I heard since he is a UI designer and he was wanting the white point of the UI elements to match the footage - so that came out of a conversation with the DP on set. So yes we are talking about exposure balance, white balance/colour temperature and debayer at the raw ingest stage. Ie. you are proving my point -  this is best done at ingest as a kind of tech grade first pass step that can always be revisited if need be. The thing you say this Light Iron guy is further backing up what I'm saying. If you need to "match shots" in DI then you should already be 90% of the way there with your first pass and CDL since by DI stage the film is 90% complete.

 

 

[Llaasseerr]

On 10/30/2019 at 2:24 AM, CaptainHook said:

Ah gotcha.

I'm not really directing this at you but just to anyone in general who isn't aware or wants to learn more, and I'm probably being a 'stickler for accuracy' here but obviously a sensor/camera has no inherent highlight rolloff as the sensor is linear (as close as practically possible with calibration) so highlight rolloff is mostly down to the dynamic range of the sensor, how the image is exposed and how the colourist chooses to roll off the highlights. All typical CMOS sensors will have "hard clipping" though, being linear capture devices.

I only say this because I see a few people mention 'highlight rolloff' as part of a log curve or colour science or something when in that respect it is just a by-product of the log curve optimising the dynamic range of the sensor in the container its being stored in. It's still assumed the user will create their own highlight rolloff in grading (I'm speaking just of RAW and log captures, not "profiles" or looks applied in camera intended for display on Rec.709 devices).

ARRI for example have a lot of stops above where they recommend middle grey be exposed for - due partly to their very large pixels and the large dynamic range they have - and when a log curve is calculated for mapping that dynamic range from middle grey to 940 (video white in 10bit where they map sensor saturation to in their log curves) you get a very flat curve at the top as it maps that range. When you flatten contrast that much it also appears to desaturate. I've seen some mention they believe ARRI purposely desaturate their highlights, but if they did that in processing before creating RAW files or LogC ProRes clips you wouldn't be able to inverse it correctly into linear for ACES workflows etc because processing like that is non-linear. They possibly do something like that for their LogC to Rec709 LUTs etc but people seem to attribute it to their LogC/RAW files too.

For our cameras we map sensor saturation at our "native ISO" to 940 also, but for ISO curve's above we go into "super whites" to make better use of the bit depth available especially since we deal so much with SDI output (10bit) and ProRes 422HQ is common for our customers (10bit also). ARRI says ProRes 444 (12bit) is the minimum for LogC because they don't use the full range available. We may change that in the future but the caveat would also be you would need to use 12bit for best results.

In theory you could expose a 10 stop camera/sensor so that you place middle grey at the second bottom stop, giving you 8 stops to create a very gentle highlight rolloff. You would just have VERY little range for the shadows. ?

So long story short, the question I would suggest people ask is 'what is the dynamic range like compared to other cameras' as that will really tell you what kind of highlight roll off YOU (the user) can create for your preference with how you like to expose given the amount of shadow information you like to retain, tolerance for noise, etc.

Well said. To speak to part what you re saying, I'm still not clear on why Blackmagic can't publish their log curve and gamut though. So we can go to linear. I mean it's one of the main reasons I never ended up buying a Blackmagic camera.

[cpc]

 

On 11/2/2019 at 9:30 PM, Llaasseerr said:

Then why doesn't Resolve offer a linear exposure adjustment tool except on the raw tab?

You can use the gain control in linear spaces. With linear material gain is equivalent to exposure adjustment (although you don't get the intuitive numerical interpretability of a raw processing exposure control).

[rawshooter]

Would be really grateful if people who own/used the camera could clarify whether or not it crops the sensor when shooting 4K CinemaDNG.

Normally, RAW video means 1:1 sensor readout. Since the FP has a 6K sensor, this would then mean a crop from full frame (36mm) to APS-C (24mm). However, it seems - from reading the manual - that the APS-C crop is only optional and the camera can record 4K CinemaDNG with full sensor readout. Is it then binned RAW?!?