S-Log for dummies?

So as stated before, you can only use S-log once you paid the price for the upgrade. I could be wrong but I don't remember any talk at all about the 8bit having an Slog ability. They said it burns in the LUT on the 8bit while simultaneously recording the 4:4:4.

I have a 1 on 1 meeting with Sony tomorrow, I'll try to get clarification on all this. I'll have the camera in my hands as well, and should be able to take some close up photos for those of you who are still interested in the "almost production" models mounting hole positions.
 
Giuseppe,

I don't think 8bit is practical for Slog - I'm just repeating what I understood to be said in Rule Boston - which is that you can record the washed out look to SxS in XDCAM-EX (with paid upgrade). Not high enough fidelity to actually use for anything but the offline edit.

But hey - I'm talking out of my rear, just parroting what i'm hearing. So, I welcome any *real* information you have.

Can't wait. I'm feeling like it's going to be week 2 of February.
 
RAW formats record the individual sensor photosite data values to a clip file, even if there is gain, noise reduction or compression of one kind or another applied. The demosaic and encoding to a standard image format take place in post camera processing.

Encoded video formats, however processed, record fully defined RGB or YCbCr pixels to a clip file. The demosaic or matrix processing and encoding take place in camera regardless of whether it is a single chip or 3-chip camera system. S-log is a gamma curve applied in camera then recorded to the encoded video file of whatever format. At the high end this would be at least a full 10 bit 4:4:4 format with minimal compression for maximum flexibility in post. With Sony this would be like HDCAMSR or whatever solid state file format Sony is creating for their new recorder and the F3. In FCP, Quicktime Prores 4444 would be the highest quality followed by Prores 422HQ. Theoretically if you ingest or transcode a video file, the recorded gamma curve should be preserved unchanged. Unfortunately this is not always the case. Quicktime has known gamma issues that hopefully will be corrected with the next update.
 
Giuseppe Pugliese said:
So as stated before, you can only use S-log once you paid the price for the upgrade. I could be wrong but I don't remember any talk at all about the 8bit having an Slog ability. They said it burns in the LUT on the 8bit while simultaneously recording the 4:4:4.
Click to expand...

Yes, I have heard that several times in the recorded sessions from Sony marketing people. Slog is meant to be used in the 10bit 444 material. The logic behind the LUTs being burned into the 35mBit material is one is supposed to be using this material for proxies and, of course, the material couldn't handle the stretch in post so it is applied in a one-pass burn in before it is dithered down to 8bit 422.

Looking forward to your report.

BTW I heard, the cameras are supposed to be in the distribution channel in Canada on the 29th so you being in NYC could get your hands on a shipping demo unit tomorrow.
 
The workflows for S-LOG on the F3 already exist. Apart from the S-Log whitepaper why not checkout the F35 user manual http://ws.sel.sony.com/PIPWebServices/RetrievePublicAsset/StepID/SEL-asset-152645/original/F35_OPERATION_MANUALAUG09REV04.pdf

open the PDF and search S-LOG. Will help fill some blanks for new users.

FWIW S-Log can be utilised through standard HD-SDI @ 10 bit. The dual link function enables 12bit 444 recording. Im not sure where / how these processes will effect overall DR. Need to wait and see the F3 for that.
 
So now we know the camera will operate in S-log exactly the same as the F35, not sure why I thought it wouldnt, but wondered if there'd be a dumbed down version.

SO you need -

SLOG to REC.709 LUT applied for onset monitoring.
HDCAMSR deck or similar to capture

The beauty is in the ability to use the SXS cards to capture simultaneously for an offline edit.

So to use S-LOG you will need

Upgrade (any word on price?) by my estimates most likely 5-7K
HDCAM SR DECK around 10K

So on the base price of 13K for body you're looking around the $30k mark (without lenses) to be S-LOG ready. That's a huge reduction on what it cost previously to purchase an S-Log camera system. When released Im going to be looking for a rental to give it a run.
 
Rumors float with the camera upgrade price as low as $1k. Which really wouldn't suprise me horribly - it looks like we'll all be able to download the firmware update, but then you need a license key. This suggests the camera already has the capability, it's just turned off. If Sony doesn't make the license fairly affordable, I would assume there might be an independent effort to crack the license or the firmware entirely.

The lower the upgrade cost, the less incentive for those enterprising souls...
 
Noel Evans said:
So now we know the camera will operate in S-log exactly the same as the F35, not sure why I thought it wouldnt, but wondered if there'd be a dumbed down version.

SO you need -

SLOG to REC.709 LUT applied for onset monitoring.
HDCAMSR deck or similar to capture

The beauty is in the ability to use the SXS cards to capture simultaneously for an offline edit.

So to use S-LOG you will need

Upgrade (any word on price?) by my estimates most likely 5-7K
HDCAM SR DECK around 10K

So on the base price of 13K for body you're looking around the $30k mark (without lenses) to be S-LOG ready. That's a huge reduction on what it cost previously to purchase an S-Log camera system. When released Im going to be looking for a rental to give it a run.
Click to expand...

You can get the dynanamic range S-Log affords by recording to a Ki Mini. Lot less than $10K
 
Noel Evans said:
No you cant. Anything recorded to the ki pro mini will have the applied LUT baked in. The RAW function is gone.
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Slog is still just a gamma curve applied to encoded video. It is not in any sense of the word raw. It is just better for grading for film transfer or digital cinema when recorded to a high end video format like HDCAM-SR.
 
Nate Weaver said:
You would record with the LUT off.
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Technically speaking S Log Gamma can be turned on like any other gamma setting and then recorded to the ki pro, yes, and thats a great function for an offline. But it defeats the purpose of what S Log is designed for.
 
Razz16mm said:
It is just better for grading for film transfer or digital cinema when recorded to a high end video format like HDCAM-SR.
Click to expand...

Which is essentially my point as this is where you'd get all the benefits of S Log and its DR.
 
Noel Evans said:
Technically speaking S Log Gamma can be turned on like any other gamma setting and then recorded to the ki pro, yes, and thats a great function for an offline. But it defeats the purpose of what S Log is designed for.
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What is it designed for? Benefits of S-Log have nothing to do with 4:4:4, or HDCAM SR. I understand clearly that Sony would have you believe it's an all-or-nothing proposition with 4:4:4 and HDCAM SR, but if you really understand what's going on technically, S-Log by itself is very valuable.

As long as you record S-Log to a 10bit codec, in any fashion, you get it's benefits.

Lots of F35 and Genesis users do S-Log to 4:2:2 HDCAM SR mode. Been doing it for a while now...4:4:4 is usually saved for effects shots in my experience. Same with Alexa users, doing LogC to ProRes 4:2:2
 
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Razz16mm said:
Slog is still just a gamma curve applied to encoded video. It is not in any sense of the word raw.
Click to expand...

As it's been told to me by one of the Sony Japanese project managers, it bypasses the detail processing block, and the color matrix block. So closer to RAW than just a gamma curve applied, but...

But generally, yes, I agree it's not RAW and it shouldn't be called such.
 
Nate Weaver said:
What is it designed for? Benefits of S-Log have nothing to do with 4:4:4, or HDCAM SR. I understand clearly that Sony would have you believe it's an all-or-nothing proposition with 4:4:4 and HDCAM SR, but if you really understand what's going on technically, S-Log by itself is very valuable.

As long as you record S-Log to a 10bit codec, in any fashion, you get it's benefits.

Lots of F35 and Genesis users do S-Log to 4:2:2 HDCAM SR mode. Been doing it for a while now...4:4:4 is usually saved for effects shots in my experience. Same with Alexa users, doing LogC to ProRes 4:2:2
Click to expand...


Yeah, this guy. I've been trying to explain that logarithmic gamma curves have nothing to do with chroma subsampling for a while now. Bit depth is far, far more important when dealing with log output. 444 is saved for very very heavy post work, or if the output is going to be scaled up by a large percentage. 422 is visually indistinguishable from 444 unless you're dealing with a source outputting very very hard per-pixel contrast such as computer generated output with very small font. A digital cinema imaging sensor will not provide that much per-pixel contrast to push 422 to the point of plain visual distinction. An argument that can be made for 444 is that it is providing, indirectly, when converted from ycbcr to an rgb color space, 1:1 rgb output which would allow you to an extent adjust white balance in post. But you are still dealing with the already exposed r g and b channels as you are with 422, and in my experience an rgb offset adjustment holds up just as solidly on a 422 DI as a 444. (Unless of course your source is dealing with under and over exposure information, such as a cineon or DPX sequence). 444 is not a magical format that allows you to fix things you got wrong the first time around, save that kind of thing for formats dealing with raw sensor output and over/under information. And even then, you still only have a little leeway.


Here's a nice comparison (albeit grainy), you're going to have to save it and zoom way in to see any difference. The source was a 12 bit RGB scan of 65mm TODD-AO


chromasamplingmethods.png




All that said and done, from sony's whitepaper it still seems they are not allowing s-log output out of a single HDSDI port. I don't want to sound like a conspiracy theorist, but it honestly sounds like they are protecting their market infrastructure, and don't want you taking advantage of something as high-end as logarithmic output without spending more money on an HDCAM deck first. I dunno though, could be several reasons! We'll find out for sure when the firmware release comes out.
 
From the Rule Boston presentation, it was stated that once you have the S-Log upgrade you could turn on or off LUT for monitoring purposes. This would imply that With the LUT off it should be possible to record 10bit 4:2:2 out of the "monitoring" HD-SDI port. If this is indeed true, Aja Ki Pro Mini should do the trick.

Also, the brochure says you'll be able to select either Dual Link or 3G SDI. And there's no requirement to use a Sony recorder. For studio or narrative work one might be able to get away with a $1000 decklink Extreme HD 3D card in a Mac Pro. If Sony's offering is priced over $10k, people will get the Cinedeck Extreme instead, which is $10k, records to off the shelf laptop harddrives, and has a monitor built in.
 
I have 10 dollars that says when the S-Log update hits the ground, it will have an option to make that Dual Link A channel output just a straight 4:2:2 10 bit output. People need to be able to step that down to keep compatibility on F35 shoots, plenty of which shoot 4:2:2. Tethered, no less.
 
Makes sense Nate. Hope you are correct. One thing to keep in mind about the Cinedeck, as amazing a piece of technology as it is, the unit is known to be a bit unstable in a production environment. Reports of having to reboot the unit on the set are known to happen and it can put things on pause for 10 minutes while the thing gets back up and running again. You can be pretty sure the Sony recorder will just work.
 
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