F5: F5/55 RAW noise vs XAVC noise

G

Gene Sung

Veteran
I have a question since you F5/55 guys are a bit higher end than us FS700 7Q guys.

On the FS700 + 7Q, when you do the same shot recorded in RAW (with S-Log profile) vs S-Log internal AVCHD in low light, obviously the RAW is overall better, but RAW can be much noisier than the same shot in AVCHD. I'm no tech expert, but for codecs like XAVC or AVCHD, does the camera smooth out the noise internally for you? Is that why RAW looks so much noisier than the compressed AVCHD codec because there is no internal noise processing?

Is this also the case with F5 / F55 RAW vs XAVC with the same shot? Are the noise amounts similar or does XAVC have less noise than RAW?
 
AFAIK the raw doesn't have any noise processing (shooting on an F55). I think the upcoming firmware is going to address this. I tend to rate the raw 1/2 stop or so over to deal with this.
 
Yes the new firmware is suppose to enable noise reduction in cineEI mode, hopefully that means RAW and XAVC.

I can tell you that the SR codec on the F55 seems much nicer and cleaner than XAVC, but I haven't tested it extensively. I have been shooting XAVC primarily, and now some RAW depending on the project.
 
Right after I got my 55, I shot some raw that had noise reduction applied. It was night exterior, and it created some ghost edges of fast moving darker objects in the frame in the raw. I wouldn't want that burned into my raw...for raw, I'd leave that NR to Resolve or Neat in post.

The onboard codecs will smooth out the noise as part of encoding. MPEG50 reduces noise the most (but also is the least sharp of all the codecs), then XAVC, then SR.

The camera has noise in the shadows at rated ISO. It just depends on subject matter and how you exposed it whether it's going to be too much or not. Vast majority of the time, it's no big deal. Also, doing black balance once the camera warms up if you're doing say, night exteriors will help it some.

On the whole, the noise level is *really* similar to Alexa. Alexa at 1250 and 55 at 1250 are neck and neck I feel. The only downside to rating the 55 lower at say 800 is you lose a little highlight latitude, but honestly, in practice, it's no big deal.
 
gene_can_sing said:
Thanks Dennis, so just to clarify: RAW does have more noise than XAVC on the same, low light type shots?
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It's maybe subjective. I wouldn't say RAW has more noise than XAVC or vice versa, but XAVC has some extra artifacts which is not exactly "noise" if you know what I mean? RAW is less lossy, so "cleaner", but if you try some post NR you will not be disappointed with either one.
 
I think a great part of this entire issue is related to the exposure of RAW Slog, as opposed to in-camera Slog. I see a significant difference in O7Q RAW vs. O7Q 4k2HD, simply due to exposing 4k2HD in a more experienced way. When I nail the RAW exposure, the end result looks, as expected, better than the 4k2HD. Doug Jensen has a really good write-up of exposure methods for the F55, which is no less valid for the FS700+O7Q. RAW, whether it's coming from the FS700 or F5, exhibits the same noise in the shadows when the footage is underexposed. It's the nature of Slog (2)(3) to push all the dynamic range higher by 2 stops. In tandem with that push is a loss of detail in the shadows. Trying to recover detail in underexposed areas will ALWAYS show how painfully low the signal/noise is. Boosting signal boosts noise...and thats just a fact of physics.

If there's any criticism to go around, it would be that Sony just dumped Slog on the user arena without much explanation or guidance on exposure and use.
 
cuervo said:
If there's any criticism to go around, it would be that Sony just dumped Slog on the user arena without much explanation or guidance on exposure and use.
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It's so very, very simple if the cameras support LUTs and the LUTs are available from the get-go for post. Arri had all of it in place, ready to go when Alexa hit the market. White paper, quick start guide, LUT website easily found for downloads...

Sony only had a white paper, no LUT downloads, spotty in-camera LUT support.
 
Can anyone speculate this type of behavior from a company who sells products for profit?

Really, I'd like to hear the theories.
 
Yeah - It amazes me that RED came out with an elegant, simple solution for this right away and Sony did absolutely nothing.
 
Lenilenapi said:
Yeah - It amazes me that RED came out with an elegant, simple solution for this right away and Sony did absolutely nothing.
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The concept is simple, whether it's raw or log with LUTs:

Record a wide latitude signal that is all the sensor is capable of resolving (spatial resolution AND dynamic range), and present to the user a nice, normal, pretty picture at all times.

Red got this right. It's almost Apple-like in it's simplicity, and it's the biggest reason there is so much good Red images out there even though some of the user-base is not post savvy. It required a lot of post software, plugins, and SDKs to make it happen, but they persevered and did it.

Arri knew the more hands-on, let the shooter see the guts approach would work too, if they told you how it was designed to work and gave you everything you (and everybody else involved, especially post) needed.

Sony. Eegads. Sony's engineers knew how it could work. They knew how to make it work. But every other part of the organization doesn't understand that users need info & tools to make it work. The camera doesn't exist in a vacuum. I am constantly amazed at how the 5 and 55 did not take off until we had the LC709 LUT in camera, and .cube files for post.

I know there's a lot of shooters here that don't understand what the big deal is about LUT and their usage, but Red had them from day one and Alexa had them from day one, and those two cameras defined the market and procedures the F55 was supposed to muscle in on. If the ENG/new to s35 market never embraced s35 and the 5/55 to get the sales through the rough first year, the two cameras would have been dead in the water from a film production standpoint. Cuz god knows they poo pooed up the first year good.

I pray that going forward, Sony decides to BUILD on the F55 rather than throwing it out for the next round of cameras in that price segment. All they would have to do is put the F65 sensor in a F55, add ProRes and ability to record raw the full 6K (or 8K) sensor, and they will win.
 
The beauty of the RED approach is not only do you have a great LUT from the get go, but you can paint it in the camera right away to see exactly what you want it to look like.
Sony already has that software built into their 709 gammas , so why not just use that to make adjustable LUT's for SLOg . This cannot be that difficult.

I have not seen how the Slog3 to 709 LUT works yet. Can you alter it in the menus?
 
The RAW on F5/55 is not noisier per sa. Its just apparent.
(as Nate stated) the codec versions hide some of the noise (albeit to the detriment of sharpness)
And I also believe noise is best left for post processing with resolve or neat if dealing with RAW.
I cannot stress how big the difference is dealing with raw noise in post is as apposed to in camera.

Ive had what i thought were unusable shots due to under exposure (run n gun following a guy into a dark waiting room at an event that I wasn't allowed any lights) and with RAW and neat I was able to completely save the shot and grade the heck out of it and the end result was a super clean sharp image that still gives me a smile every time I think about it.
Im from an F35, its 450 ISO native with very little shadow room, and the difference in what I could get in low lit situations with F5 RAW alone made my decision to move to the F5 justified.
De-noising even a 12bit 444 Prores file in post can't even compare to de-noising RAW. Ive tried this with in 12bit 444 exact clips made from Raw. Its like magic. I use neat btw.
You can also selectively qualify shadows only to de-noise, if your mid tones & up are fine.
 
starcentral said:
Can anyone speculate this type of behavior from a company who sells products for profit?

Really, I'd like to hear the theories.
Click to expand...

Sony is a major corporation bleeding money. It does not put all it's eggs in the video camera market. It must generate constant income and TURNOVER. It's priority therefore will not be to create one camera and build on it, but rather new cameras which function more like consumables than long term workhorses. This is obviously, a completely different philosophy than RED or ARRi. It means that the R&D department which created a particular camera, has already moved on to a new project by the time the camera hits the market. The lack of long term oversight for a product like the F3 is more a reflection of the way resources are allocated than a particular lack of reflection about a specific issue like LUT's for example.
 
I think, this behaviour with LUTs will have a solution, the FS7 seems to have already built-in:

PXWFS7preso.098_640_360.jpg

Alistair wrote something in his review, too:

The FS7 has two different shooting modes. In custom mode the camera behaves pretty much like any other conventional camera where what you see in the viewfinder is what’s recorded on the cards. You can alter the cameras gamma curve, matrix and other settings, but basically what you see is what you get. The other mode is the CineEI mode (just like an F5 or F55) and in this mode the camera records using SGamut3.cine and S-Log3. The aim being to capture the maximum possible dynamic range and in this mode the cameras sensitivity is locked to it’s native ISO of 2000. As S-Log3 results in a very flat picture (that’s great for grading and post work) the camera includes the ability to add a range of Look Up Tables (LUT’s) to the viewfinder or HDSDI output. LUT’s help you better judge exposure and give a more pleasing image prior to grading. You can even generate your own LUT’s in software such as Resolve and load them in to the camera. For exposure assistance the camera has a range of tools including a waveform, vectorscope or histogram display as well as zebras.

more here: http://www.xdcam-user.com/2014/09/sonys-new-pxw-fs7-first-impressions/

Basicly, this should give us the ability to use (even our own) same LUTs on set and in post. That means we are capable of the wohle LOG/LUT workflow from shooting to grading.
Doesn't have the F5/55 the same functions?
 
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Yes Erik F5/55 has it now but did not have it when they first came out of the gate.

It took 1 year after cameras were launched to have this. Here's the history for anyone interested:


V3.0 December 2013: User LUT (1D) and 4 types of Sony Look Profiles 3D LUT are added for Monitor LUT selection. You can create User LUT by using RAW Viewer V2.1, and up to 6 User LUT can be stored on the internal memory via an SD card. Sony Look profiles provide easier starting point of color grading for TV workflow. For detail information, please refer to the document “Sony Look Profiles Summary”.

You can set Monitor LUT On/Off for SDI(Main)&Internal Rec, SDI(Sub)&HDMI, and Viewfinder independently.

V4.0 April 2014:*User generated 3D LUT’s via RAW VIEWER and DaVinci Resolve as .cube files of either 17 or 33 latices are now supported for upload into the cameras.

The PMW-F5/F55 can import a CUBE file (.cube) of 17 or 33 lattices that is created by RAW Viewer or BMD’s Da Vinci Resolve.

V4.1 June 2014:*Support of MLUT while recording XAVC 4K/QFHD (F55 only) :*When the recording format menu of F55 is set to XAVC 4096x2160P or XAVC 3840x2160P, MLUT for “SDI (Main) & Internal Rec” is available.
 
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