SLOG2 picture profile

I had the day off so I did some major pixel peeping on S-Log.

Remember a while back when S-Log first came out and I complained about how Saturation destroys S-Log?

Well, I realize now it's because when I first started messing with S-Log, I was exposing it like I do with Cinegammas in bright daylight, usually a stop or maybe a bit more under exposed (to the Left). From major pixel peeping, I figured out that the more you under expose S-Log, the more macro blocking happens when you re-introduce Saturation. It seems that when I exposed the shot in the middle of the Histogram, it took to grading / saturation quite a bit better than when I under exposed it.

While I still don't think you should add a ton of saturation, but it definitely improves as the histogram hits the middle, or very slightly right IMO.

I shot some tests with my friends kids the other day and exposed it in the middle and I really love the results. The highlights are insane, and the there's definitely more shadow detail as well than Cine 4. I took Cuervo's advice and looked more at the Histogram as opposed to the Zebras, and I liked what I got.
 
Last edited:
It sounds like you guys don't really agree with the official rating of the camera at 2000 ISO for SLOG2. What would you rate the camera at for acceptable results with SLOG2?
 
If you're working off the histrogram, you're not really paying any attention to the ISO (at least I'm not!) - the histogram tells you most of what you need to know: i.e. if your image is going to have any areas of under or over exposure and the zebras tell you where they are (the over exposure bits anyway. A false colour image is really helpful to show you the black clip areas if you have a monitor that has that function). Of course the assumption is that you'll grade it in post to put the skin tones or whatever where you want them.


Having a 'correct' ISO is really only relevant if you're exposing based on a light meter reading - and want to be sure that you're placing the mid greys 'in the right place'. But as Skylike points out, 'the right place' can is very dependent upon the gamma curve being used - and the post path it's going through. In which case the 'correct' rating for the curve will depend upon how the footage is to be graded (or not graded).

Which is basically to say: these are two quite different methodologies to setting your exposure.

I've not really had a chance to nerd out properly with SLOG-2 yet. But I might run a few tests in the next couple of weeks to see what works for me. One thing I'm interested in is whether you get more noise bringing up the floor at ISO 2000, or shooting ISO 4000 (for example) and pulling it back down.
 
I've finally had a chance to throw some of the Slog2 footage I've been shooting in resolve to see how grades. To be honest, exposure was a bit all over the place (and I don't envy the guy who has to grade all the do co footage I shot!) and as my main concern was always to avoid white clip (and noise in the blacks) I tended to over expose everything - but every now and then I got the exposure 'correct'.

My basic approach was to throw it into Resolve and apply the Sony Slog2 LUT.

First thoughts are that you get a crazy amount of DR - once the LUT unpacks the image it's way outside the limits of Rec709 - which you can then pull back in. Shots that were simply impossible before now seem much more viable. I shot straight into the sun at sunset and managed to keep detail in both the clouds and the foreground subject. I shot a day car interior and held the subject (albeit a little under) and the window. I shot a lot in bright sunshine and the shadows just weren't a problem.

I terms of exposure, the 'correct' exposure seems to lead to a bit more noise than I like. What seems to work really nicely is to overexpose, apply the LUT then pull down the gain. In other words I'd probably 'rate' the camera at ISO 1000 or ISO 500 still (if you want to present your grader with a consistent exposure) - but don't quote me on that as I haven't bothered metering anything, or done any tests - I just went out and started shooting stuff and going its what felt right (yeah, yeah, I know - but where's the fun in testing before using in anger? I like to live on the edge)

I even have a soft spot for the milky ungraded look of raw Slog2. To be honest, I'm not sure I'm going to bother shooting much with the other profiles. I compared Slog with the Abel cine EOS and AB_Range profiles and they just didn't cut it.
 
Is there a way to use the Sony Slog2 LUT in Premiere Pro CC?

Do you guys render the footage for grading in Resolve?
 
I'm in the middle of shooting a feature and instead of trying to shoot the whole thing with Slog2, I'm only using it to solve sticky situations where the highlights are out of control, such as shooting in a shaded area with a full sun background. It is a lifesaver in those situations! And it can be easily graded to match the footage shot in normal profiles.
 
Colin,

Which LUT are you using in Resolve?

I only have a 1D LUT to Rec709 showing, and to my mind that's not ideal (as there would have to be an additional LUT to get into Linear for resolve internally). I was expecting a LUT direct from SLog to Linear space.

Do i just not have the right LUTs here? I've only found SLog to either a graded look or Rec709 so far.

I wonder what the rationale for SLog being 2000 ISO as a base, compared to the other profiles? I can understand your exposure approach in this case because even 2000 is quite noisy.

cheers
Paul
 
Essami said:
Is there a way to use the Sony Slog2 LUT in Premiere Pro CC?

Do you guys render the footage for grading in Resolve?
Click to expand...

You used to have a separate effect to apply a LUT but in CC you can add an adjustment layer and apply a speedgrade look that has a LUT within it. Then in the next version you can just switch between PPro and SG with the same timeline and do the colour work in SG.

At the moment i roundtrip between PPro and Resolve but look forward to trying the SG workflow.

cheers
Paul
 
Addendum: it seems my previous grading was all a tad too hasty - as I realised this morning I had downloaded the wrong LUT - I had an old 1D Slog2 LUT, not the latest 3D cubes released by Sony. I have to say, the newer LUTs are a real revelation! Footage in the 1D table that looked over exposed just looked awesome! They do a really fantastic job of translated the massive range of the profile into regular colour space. As an example: on one shot I flipped in out one of the ND filters I.e. I pulled out 2stops of ND - the shot went from looking a little underexposed, to perfect. I have to say, I really like this combination of Slog2 and resolve.
 
Colinelves said:
Addendum: it seems my previous grading was all a tad too hasty - as I realised this morning I had downloaded the wrong LUT - I had an old 1D Slog2 LUT, not the latest 3D cubes released by Sony. I have to say, the newer LUTs are a real revelation! Footage in the 1D table that looked over exposed just looked awesome! They do a really fantastic job of translated the massive range of the profile into regular colour space. As an example: on one shot I flipped in out one of the ND filters I.e. I pulled out 2stops of ND - the shot went from looking a little underexposed, to perfect. I have to say, I really like this combination of Slog2 and resolve.
Click to expand...

sounds great, thanks for sharing. As I have almost no experience to Sony sLog2 it would be a great help if you could share the download link for the latest LUT you mentioned? thanks in advance!
 
Okay, I promise I'll quit posting on this subject at some point but - I'm just putting out stuff as I come across it. So...

having now exported a lot of the (roughly) graded footage and done a little pixel peaking, I'd say my findings match well with a lot of other people's

1. There is a lot of noise in the mids and shadows, and just a little bit of underexposire will bring it out. As we're talking 8bits only here, and a curve that uses most of those bits for the highlights that noise is very noticeable - as there is a tonne of banding and blocking in those bits.

To definitely err on the side of over exposure!

2. Don't add too much saturation back in. as this causes a lot of blocking in areas of strong solid colour (e.g. rich blue skies).

So, to summarise: the range the profile can give you is great, but be careful with it! All the data is in the highlights so try to put everything import there...
 
Last edited:
I had a similiar issue with Noah Yuan-Vogel settings. At the first sight great to keep highlights and to get a wide dynamic range but bringing up noise very soon even in low ISO settings. It's probably the 8-Bit price you pay. I hope C-D 7Q will improve this already with 10bit 422 ProRes
 
Last edited:
I'd underline Colins findings too

The shadow section of the log curve is very subtle and, in 8 bit, leaves very few values to use.

Within the 8 bit container, values 150-255 are holding highlights from 90% upwards. Those 150 values below have to record everything from black to 90%. In 10bit that value is closer to 600 which offers a lot more gradations to work with.

This isn't to say SLog in 8 bit won't work. We shot scenes over the weekend where we wanted that log highlight look because of the story. But as a general approach i wouldn't default to it. Alistair Chapman has done quite a bit of R&D on 700 profiles and he has a very nice overall profile on his site that seems to work very well. Personally (on another note) you have to be very careful with the black gamma setting. You can actually get it into a situation where it does more damage than good...

cheers
Paul
 
The LUTs are here: http://community.sony.com/t5/F5-F55/NEW-3D-LUT-s-for-F55-and-F65/td-p/135617

Following on from what Paul says, I might be tempted to use Slog2 a lot myself, as I think the results can be really fantastic - but I'd probably only want to use it in situations where I know there is a huge amount of highlight detail I want to keep (i.e. bright sunny days, or a window in shot) *and* if I know I can have some input into the grading. Or for those situations where the 'log look' seems right (i.e. super washed out, super low contrast).

In all those situations, however, I'd probably shoot to the right, effectively over exposing those mid tones to bring them more up onto the curve where the detail is. On the stuff I've shot so far with it (and it is extremely varied!) I've always kept the zebras at 100%+ and opened up until they start coming on - and operning up more if the skin tones still look 'under' in the log view.

Outside of those situations, where I have no idea how (or if) it will be graded, I tend to use the Abelcine profiles a lot. The AB_EOS profile is good for those situations where you're just not conviced the client will grade and the AB_Range works well if you think they might give it a little tweak but not much more. I've tried Alistair chapman's and Noah's profiles, but tended to shy away from them as they're based on cinegamma 3/4 which always seem quite noisy to me.
 
Art Adams wrote a great article on FS700 S-Log 2 and the 4K.

http://www.dvinfo.net/article/acquisition/sonyxdcam/fs700-the-4k-story-from-my-perspective.html

He says after lots of testing (which verifies many of our findings):

I don’t recommend exposing to the right with any other camera (excluding projects where each shot is a stand alone beauty shot) but it works very well with this one. Adam and I found that a great compromise is to expose log in the center of the histogram, and indeed most of our test footage was shot that way.

What worked best for me was exposing S-Log2 in the center of the histogram. I captured a lot of information and the image still looked reasonably good on the LCD display.

Art also mentions about 14 stops on FS700 S-Log 2 when shot on the charts.

 
Last edited:
It sounds like it is worth rating the camera at ISO 500 and exposing using a light meter. Then you get a consistent expoure for the grader, but maximise the capabilities of the camera.
 
At ISO 500, wouldn't you be afraid of blowing out the hilites? I've played with various amounts of over-exposure with Slog2, wanting to maximise the content. It is possible to turn the shadows into a muddy mess and clip the hi's.

Personally, I can't wait for C-D to release the O7Q. With display LUT capability, being able to see the "graded" image will be indispensable.
 
Last edited:
I have a shoot coming up where we want to light most of the scene with a big bonfire, action happening in front of it and people being mostly in silhouette. Maybe we want to open the dark side up a bit with a 2K tungsten with heavy diffusion far away. Is this a situation where you think using s-log would be beneficial because you don't blow out the fire or will it fall apart because of the darkness around the fire?
 
You must log in or register to reply here.
Back
Top