The correct way to expose for SLOG3 when using 8bit cameras

[kidzrevil]

I've heard a lot about how awful the Sony Log profiles are and how we should stay away from them. Well after testing them extensively I conclude that it's not the profile that's inherently bad its how people are grading them especially when they use the in camera meter to set exposure and not the zebras. LUT's like visioncolor impulz are very aggressive on the blue channel and exaggerate noise. I find Koji advance and Filmconvert to work  best with SLOG3. The official Sony LUT also gives you a nice neutral look with desaturated highlights. I found that If I use the expose all the way to the right exposing the brightest object to fall on 94 ire I do not get banding or color noise. 95 ire with slog3 correlates with the 14th stop of the camera so you are technically not losing data if you expose for the brightest stop. What that does is dedicates the rest of the sensor dynamic range to capturing all the shadow detail below the 14th stop (max brightness) which is incredible. When you underexpose and brighten in post is where all the problems start so my rule is shoot 2 to 3 stops over placing the brightest object you want to keep in post at or directly underneath the clipping point. Please keep in mind everytime you go up a stop you rate the ISO lower so 3 stops over on the a6300 and a6500 is 100iso. When you lower your exposure in post the image really pops and all the garbage data gets thrown away

[mercer]

Interesting, when I had the a6500 and RX10ii, I would try and keep the in camera meter between +1.7 and 2. Turn on zebras to make sure nothing was clipping and then turn them off.

With a manual lens, wide open, I would use Auto ISO (with the a6500) and set my max ISO to either 1600 or 3200 and then ride the variable ND to keep within +1.7 - 2 stops. To use Auto ISO with a manual lens was an amazing feature that I believed helped a ton.

With the a6500 I used sLog3 with the factory settings, save for lowering sharpening or detail (whatever they call it) ... with the RX10ii and sLog2, I had the bright idea of messing with the settings... which I believed actually hurt me in the long run.

Anyway, interesting read and if I ever get another a6500, I will definitely test your method.

Btw, what is your favorite non-cine/sLog profile on these Sony cams?

As I’m sure you know, I’ve been happily addicted to my 5D3 and ML Raw, but I kinda need a second grab and go camera... preferably a point and shoot because I don’t really want to invest in another ecosystem and I don’t want to buy a speedbooster for my manual lenses... so that leaves either a point and shoot or a Nikon. I kinda want to wait on the Nikon until the successor to the D5600 comes out with 4K... so a point and shoot it is.

Anyway, as I said, I had the RX10ii earlier in the year and really enjoyed the all in one aspect of the camera. It has good audio with headphone input, built in ND, etc... but I sold it to buy my 5D3.

One of my options is to pick up the original RX10 since it is so cheap now. On occasion New ones pop up on eBay for less than $500. I only need 1080p and that is right around the most I want to spend... so it could be a great option for me.

I have been watching a bunch of videos online and it seems standard, portrait and neutral are the favored profiles... what say you?

[maxotics]

Hey, if you get the image you want, great!!!!  But I'm one of those people who are very critical of LOG profiles.  I don't see what you gain using them in those shots because you crushed the contrast so heavily you even removed the noise inherent in the higher ISO the camera uses to achieve a LOG distribution of visual data.  That is, you could have arrived at the same high contrast footage, with more color depth, shooting rec.709.  The shot where she is on the staircase and part of the background is blown out, I could see LOG used there, but you don't use it to bring out the background, the dynamic range is severely narrowed in the end.  

LOG profiles only make sense to me when there is detail in part of the image (5+ stops away) that one wants even at the sacrifice of color saturation.  One cannot get color back.  

Don't want to rain on your parade!  I love what you did. Nice images, however you got them! But to be fair to yourself, shouldn't you have shot the scenes both in standard profile and LOG and THEN compared them?  LOG trades higher saturation for higher contrast detail.  There is no exposure trick to get your color back   That footage can never be made to have more color depth.

In short, if you want to show how you get the most out of a LOG profile, shoot a scene where you make a trade-off you can't get with rec.709. Why do you believe those scenes were better shot with LOG?  Again, I know you put a lot of work into this!  I enjoyed it!  I think you should go out and do some more!

 

[Mattias Burling]

My problem with slog3 was never the grading. It was the banding which is there in camera and after.
Nothing to do about it really. 

And I wouldn't mind if it wasn't for the A7sii I had costing more than my complete Red package, a RX1rii + bmpcc combo, way more than a Leica Q and even more than my complete DSLR setup  including great glass that I use today.
If the camera was cheap.. then it would be ok imo.
 

[andrgl]

6 hours ago, maxotics said:

Hey, if you get the image you want, great!!!!  But I'm one of those people who are very critical of LOG profiles.  I don't see what you gain using them in those shots because you crushed the contrast so heavily you even removed the noise inherent in the higher ISO the camera uses to achieve a LOG distribution of visual data.  That is, you could have arrived at the same high contrast footage, with more color depth, shooting rec.709.  The shot where she is on the staircase and part of the background is blown out, I could see LOG used there, but you don't use it to bring out the background, the dynamic range is severely narrowed in the end.  

LOG profiles only make sense to me when there is detail in part of the image (5+ stops away) that one wants even at the sacrifice of color saturation.  One cannot get color back.  

Don't want to rain on your parade!  I love what you did. Nice images, however you got them! But to be fair to yourself, shouldn't you have shot the scenes both in standard profile and LOG and THEN compared them?  LOG trades higher saturation for higher contrast detail.  There is no exposure trick to get your color back   That footage can never be made to have more color depth.

In short, if you want to show how you get the most out of a LOG profile, shoot a scene where you make a trade-off you can't get with rec.709. Why do you believe those scenes were better shot with LOG?  Again, I know you put a lot of work into this!  I enjoyed it!  I think you should go out and do some more!

 

Who the [...] has time to make profiles to grade their footage in camera?

Way easier to shoot log/flat and then grade to whatever look needs to be achieved.

-edited

[maxotics]

10 hours ago, andrgl said:

Way easier to shoot log/flat and then grade to whatever look needs to be achieved.

I'll try to put as succinctly as possible.  Sensor outputs data in the range of 4 trillion colors.  The most accurate colors are within 5 stops of a certain (correct) exposure.  Those 5 stops of most-accurate color take up 16 million values (the maximum that can be stored in an 8-bit-per-color-channel data container).  When you shoot LOG, the camera throws out accurate colors for noisy ones, above and below the 5-stop center of best exposure.  You cannot grade the center-best values back. 

One doesn't have to take the time to understand what goes on under the hood of their camera, so to speak.   But one day they will make a fool of themselves when they shoot LOG for a client and the client can't match it to footage shot by someone else, that maximized the color sensitivity of the camera.   When they try to bring color back, the contrast will appear cartoonish, when they try to match the contrast, the colors will look washed out.  That's the corner you shoot yourself into with LOG in a scene that doesn't call for it.  

15 hours ago, Mattias Burling said:

My problem with slog3 was never the grading. It was the banding which is there in camera and after.
Nothing to do about it really.

To add some technical facts...

Why does it band?  Because in a solid color, like a sky, you don't see just one color of blue.  You see a range of them, say 1 to 1,000.  The "stupid" manufacturers have tested their products so that when you shoot a sky, you get just enough colors, say 1,000, to accurately show the gradient sky without contrast between two neighboring colors.  Contrast happens when you essentially see TWO DIFFERENT COLORS!  Okay, so in LOG, it doesn't take 1,000 colors in that blue range say, it takes 250.  Normally, one doesn't notice.  But if you shoot a scene where there is a blue gradient sky and it shows it to you in 250 shades of blue, they will look like DIFFERENT COLORS next to each other.  That's BANDING!  Of course, they are different colors, but you don't want them so different that the brain says they're not connected!

Sadly, many people don't want to follow the logic that if LOG creates banding; that is, if LOG distorts the image there, that it does it everywhere, though not as easy to notice.

  

 

[kidzrevil]

@maxotics idk man im just not seeing the problems you have experienced with LOG profiles shooting SLOG3. The crushed shadows were a stylistic choice but I will grade the image again. If you look at the clips under a waveform and vectorscope you will see that nothing is blown out. I made sure to expose below the clipping point to prevent any kind of overexposure. 

I chose to shoot this in LOG over REC709 for multiple reasons. 1) you are shooting at the native iso and also rate the ISO slower by over exposing. 3 stops overexposed at 800 iso is an image equivalent to one shot at 100iso 2) the cameras dynamic range doesn’t chance with any picture profile only the gain does. You will always get a better signal to noise ratio over a rec709 who’s noise floor is hidden in the shadows and will quickly appear when raising them in post. 3) sgamut3.cine works better with color than standard rec709 profiles because of how it handles saturation. After around 40 ire I believe colors don’t get more saturated they just get brighter like film. That color science is not present in any other profile. 4) Im not having the issue with loss of color data or banding because I raise the in camera saturation. SLOG3 white papers suggest to raise in camera saturation to emulate printed film. In post it preserves more color information. The SLOG3 & cineon white papers both state they were made to support 8,10 & 12 bit data so the 8bit argument when shooting log is null and void. Expose up to assign the higher code values of the codec to the image and you are fine. 

So in my experience there are significant gain in using LOG profiles over REC709 under the right lighting conditions. I will regrade this to look flatter.

16 hours ago, Mattias Burling said:

My problem with slog3 was never the grading. It was the banding which is there in camera and after.
Nothing to do about it really. 
 

I have never experienced the banding problem. Do you see it present in my footage ? Im not sure if I missed it but I didn’t see ang banding when I shot or graded this

16 hours ago, maxotics said:

There is no exposure trick to get your color back   That footage can never be made to have more color depth

 

Absolutely right. There is no exposure trick to get more color depth and this is why you raise the in camera saturation. Increasing the saturation holds onto more color information. SGAMUT3 is large enough to support this extra color info without blowing out a color channel. You can desaturate in post

[kidzrevil]

16 hours ago, maxotics said:

I don't see what you gain using them in those shots because you crushed the contrast so heavily you even removed the noise inherent in the higher ISO the camera uses to achieve a LOG distribution of visual data.  

And that is the point. There is no noise inherent in the final image which = better compression. Also it is almost physically impossible to have noise in the image if the sensor is getting a signal with an exposure 2 to 3 stops over. All the shadow data is assigned to a code value in the upper range of the histogram above 40% ire where noise isn’t present before grading which also results in better compression especially since h.264 destroys details stored in the lower ire levels. Data people often try to raise in post shooting standard rec709. Also with rec709 profiles/linear curves a massive amount of data is distributed to the highlights and its another reason macroblocking and stuff occur in the lower range of the image with far less data assigned to the lower stops.

[maxotics]

27 minutes ago, kidzrevil said:

If you look at the clips under a waveform and vectorscope you will see that nothing is blown out

Waveform doesn't show color depth.  I'm not arguing exposure one way or another.

27 minutes ago, kidzrevil said:

3 stops overexposed at 800 iso is an image equivalent to one shot at 100iso

Are you trying to shock me or get a laugh?  I'm not sure you understand ISO correctly.  The core idea of ISO is to tell the photographer/videographer the amount of light that will provide the most accurate, color saturated image without any digital amplification (gain).  Anything above base ISO (usually 100) is up to the manufacturer to determine because there is no accepted industry measurement of noise expectations for higher ISOs. So not sure how to respond here.  

Again, as long as you like your final image, hey, whatever inspires, whatever you want to say visually!  I'm all for it.  But when you argue certain things to other filmmakers about what the camera is doing and how you can grade away physical limitations of the equipment,  I feel compelled to point out flaws in how you're coming to what are erroneous conclusions to me.  You could have gotten the same images you got with a flat profile and ended up with more color depth (for future grades) than if you had shot LOG.  You'd see this if you shoot a normal profile.  Instead, you shot LOG, graded, and claimed it is better than a standard profile.  Certainly, you must see the fundamental flaw there?

 I've posted this here before, just in case you haven't seen my experiements in this

 

[kidzrevil]

Im trying to shock you AND get an LOL out of you ! No seriously have you ever heard of rating film slower than the manufacturer intended by overexposing ? The opposite is true for underexposure. You should look up the principles of pushing and pulling film if you aren’t familiar because they are similar in nature especially when recording a logarithmic image. The camera isn’t gaining more light by raising or lowering beyond the native iso, it is sacrificing DR in the upper or lower range to rate the camera at a certain iso. It will always be an 800 iso sensor no matter if you select 100 or 3200 iso on the camera (the camera is only adjusting the gain hence the reason why some people prefer to read the iso as DB to avoid confusion) so I think you may have a misunderstanding of how ISO works in a camera.  @maxotics

[Mattias Burling]

31 minutes ago, kidzrevil said:

I have never experienced the banding problem. Do you see it present in my footage ? Im not sure if I missed it but I didn’t see ang banding when I shot or graded this

No I have never noticed any in your footage, it looks great.

[maxotics]

1 minute ago, kidzrevil said:

Im trying to shock you AND get an LOL out of you ! No seriously have you ever heard of rating film slower than the manufacturer intended by overexposing ? The camera isn’t gaining more light by raising or lowering beyond the native iso, it is sacrificing DR in the upper or lower range to rate the camera at a certain iso. It will always be an 800 iso sensor no matter if you select 100 or 3200 iso on the camera so I think you may have a misunderstanding of how ISO works in a camera @maxotics

You're going to get a standing ovation from me for sure   Being of that age, yes, I'm very familiar with rating film slower and developing long/shorter, etc.  However, even in film, you make a trade-off.   Shooting the grand canyon is different than shooting a portrait.  One pushes or pull films based on what they're shooting.  They aren't doing something smarter than the manufacturer who wants to optimize their product for most shooting conditions.  LOG can give you benefits in challenging lighting.   Never disputing that.   

[kidzrevil]

@maxotics now you’re understanding me. In the original post I mentioned sacrificing the highlight headroom for better noise performance and shadow detail and that is the trade off. That is very much in line with pull processing an image and is exactly what I did here. This is no free lunch and I apologize if I alluded to that but in the original post I mentioned what you do lose and what you gain from my method of exposing the image for post production.

edit : also keep in mind that I included her in the test to showcase how skintones are handled when shooting in the overexposure range. She falls under a 1.5-3stop overexposure in these scenes

[PannySVHS]

@maxotics, @kidzrevil, love your guys discussion and exchange of info. interesting read. love especially the last two shots of your footage, kidz. looking classy, classic, best 8bit sony color ever, beautiful indian summer mood.

 

I still assume it to be challenging to shoot a shortfilm with it regarding matching shots.

[kidzrevil]

4 minutes ago, Mattias Burling said:

No I have never noticed any in your footage, it looks great.

Thank God...I got worried for a second ?

[maxotics]

6 minutes ago, kidzrevil said:

Thank God...I got worried for a second ?

Yeah, and I just want to say, I love what you're doing artistically too!  But...

8 minutes ago, kidzrevil said:

otics now you’re understanding me.

I think I understand.  I get bent out of shape because there's a fair amount of snake-oil sold out there in the way of color profiles, etc (which I know you're not doing) which actually hurts the footage that new filmmakers take.  This is a very interesting subject to me because, like you, I LUST after a low-contrast look.  Nothing beats a RAW workflow in my book.  It's just beautiful.  But I'm lazy, like everyone else, and want a short-cut.  So I've tried, like you, to make LOG work.  But I couldn't for most situations.  After some experimentations I figured out why it is impossible.  But in the back of my mind, I'm still hopeful.  So when I read your post I'm like, maybe he's done it!  But I need to see certain things addressed to be convinced.  So, all good.  I'm enjoying this!

[kidzrevil]

4 minutes ago, maxotics said:

Yeah, and I just want to say, I love what you're doing artistically too!  But...

I get it, im very apprehensive about shooting LOG as well and have mentioned the drawbacks in other threads. I ran this test for those who need to shoot LOG on their productions or who are curious with experimenting with it. Any other time im shooting Cine1 & Cine3 for quick turnover times

7 minutes ago, PannySVHS said:

@maxotics, @kidzrevil, love your guys discussion and exchange of info. interesting read. love especially the last two shots of your footage, kidz. looking classy, classic, best 8bit sony color ever, beautiful indian summer mood.

 

I still assume it to be challenging to shoot a shortfilm with it regarding matching shots.

Definitely a challenge but there are ways to simplify your workflow. I use filmconvert to address that problem. I can even use it to match footage between my a6500 and pana g85. 

[mercer]

2 hours ago, maxotics said:

 Nothing beats a RAW workflow in my book.  It's just beautiful.

Max, I learned so much from your eos-m raw videos and posts that it eventually led me down the ML path to a 50D and then finally a 5D3. The workflow is pretty simple now... and if you are used to converting footage before bringing it into your NLE, it is basically the same amount of time. If you use MLVFs it’s even faster. The 5D3 and Canon lenses with IS are as steady as some variants of IBIS. By utilizing the Raw histograms with ETTR Hint, it truly becomes a point and shoot cinema camera. 

Otherwise what Nikon has done with Video DR and their Flat Profile is nothing short of amazing, @Mattias Burling ‘s D750 tests almost look like Raw video to me. I also noticed the a6500 has a Raw like texture when shooting in sLog3 with the cinegamut.

So IMO, if you want the Raw look with out shooting Raw, then try out a D5500 or D750 or if you want to try your hand at Log again, I think you may be surprised by the a6500 and sLog3 with cine gamut 3. 

But from reading your posts all of these years, I doubt I revealed anything to you that you didn’t already know. 

19 hours ago, mercer said:

Interesting, when I had the a6500 and RX10ii, I would try and keep the in camera meter between +1.7 and 2. Turn on zebras to make sure nothing was clipping and then turn them off.

With a manual lens, wide open, I would use Auto ISO (with the a6500) and set my max ISO to either 1600 or 3200 and then ride the variable ND to keep within +1.7 - 2 stops. To use Auto ISO with a manual lens was an amazing feature that I believed helped a ton.

With the a6500 I used sLog3 with the factory settings, save for lowering sharpening or detail (whatever they call it) ... with the RX10ii and sLog2, I had the bright idea of messing with the settings... which I believed actually hurt me in the long run.

Anyway, interesting read and if I ever get another a6500, I will definitely test your method.

Duh, I forgot to write that with Auto ISO and manual lenses on the a6500, you can set +/- exposure compensation... so to correct my post... I would set the exposure compensation at +1.7 and then use a variable ND to ride the exposure when the Auto ISO couldn’t adjust higher/lower than the base ISO/my desired maximum ISO... respectively.

[maxotics]

40 minutes ago, mercer said:

So IMO, if you want the Raw look with out shooting Raw, then try out a D5500 or D750 or if you want to try your hand at Log again, I think you may be surprised by the a6500 and sLog3 with cine gamut 3. 

Thanks for the kind words!  I'm super happy to hear I've helped anyone get into Magic Lantern RAW.  I currently have a 7D with ML RAW and agree, compared to those day, wow, not difficult anymore.  You're right, I'm not caught up to Nikon.  One day!  I have a a6300 and see what you see.  A monster camera, image IQ wise.  It's the ease of use thing that stops me from fully embracing them as video cameras.  I bought a used C100 and it gets me exactly the image I want right out of the camera at a reasonable file size.  I'm now as passionate about Canon's Cinema line as I was about RAW those years ago   Anyway, will try what you suggest with my A6300 the next time I shoot with it!!!  Thanks for the tip!

[mercer]

Now as everybody knows, I am not that good of a colorist and sLog grading can be tricky for experienced colorists but here is my attempt at grading some sLog3 footage I shot with the a6500 last year. Grading aside, the shot at 1:30 in, I feel shows a little of that Raw texture in the tree bark. This is the only a6500 sample I have, so I apologize for the repost...

Again, my poor grading aside, here are a few screengrabs from my time with the D5500... I loved that camera... even though it was kind of a pain in the butt to shoot with in manual mode with old Nikkor lenses... the D750 looks even better to me but I never used one.

 

And finally, yes thank you... I doubt you remember but we had a long discussion about eos-m ml Raw a couple years back and I became obsessed with it but couldn’t get rid of this dreaded pink dots. Eventually I tried the 50D (later realizing I probably should have gone with the 7D instead... I didn’t realize how cheap they are) but the lack of audio on the 50D made it a novelty camera at best. And finally, 6 months later I sold a ton of stuff to afford a 5D3... I couldn’t be happier...

 

The C100 is a great choice, would love to see how you’re getting along with it.

34 minutes ago, maxotics said:

Thanks for the kind words!  I'm super happy to hear I've helped anyone get into Magic Lantern RAW.  I currently have a 7D with ML RAW and agree, compared to those day, wow, not difficult anymore.  You're right, I'm not caught up to Nikon.  One day!  I have a a6300 and see what you see.  A monster camera, image IQ wise.  It's the ease of use thing that stops me from fully embracing them as video cameras.  I bought a used C100 and it gets me exactly the image I want right out of the camera at a reasonable file size.  I'm now as passionate about Canon's Cinema line as I was about RAW those years ago   Anyway, will try what you suggest with my A6300 the next time I shoot with it!!!  Thanks for the tip!

 

Anyway, sorry @kidzrevil for the slight OT.