Does S-Log need to be graded all the time?

Steve Kimmel · February 8th, 2012, 10:06 AM

Quote:

Originally Posted by Alister Chapman

Where I have the time to use them, I use a mid grey card at 38IRE. I allow my whites to go all the way to 107 IRE if I have a waveform monitor available (my Transvideo has a built in WFM). If I don't have a WFM then I use both zebras and the histogram and keep my peak whites below 100% as neither will show small overshoots. Remember to ensure your LUT's are off if using any of the cameras built in measuring tools. I'll often use the centre meter to spot check levels across parts of the scene by panning onto them.

Alister: I am finding that to get middle grey at 38, my highlights are falling well below 100 IRE. This means I have to up the highlights in post. Not a problem for me, but wonder if you have any advice about this?

Thanks.

Steve Kimmel · February 8th, 2012, 10:09 AM

Quote:

Originally Posted by Doug Jensen

No doubt the F65 is a great camera. but even at that price, if I traded my F800 for an F65 I'd go out of business pretty fast. The different workflow requirements and hassles associated with the F65 would kill my productivity. I don't work in Hollywood and don't pretend to work in Hollywood. I work in broadcast television and corporate video, and the F65 is way overkill. There's nobody I work for that would have any idea what to do with those files.

The F800 & F3 combo is working out pretty well for me.

How do the F800 and F3 cut together?

Doug Jensen · February 8th, 2012, 01:15 PM

Steve, I think the F3 and F800 would cut together seamlessly, but I've never actually had any reason to use them together on a multi-camera shoot. Even without taking the time to set them up side-by-side, I can already tell the the paint settings I use on each camera come pretty close to the same look. No surprise there, since I programmed them both to give me the standard look I like on any camera.

To answer your other question, when I expose for S-LOG I want my bright whites at around 68% and/or my 18% gray card at 38%.

Alister Chapman · February 8th, 2012, 02:11 PM

Exposure is not something that is set in stone. The idea behind setting reflected mid grey at 38 IRE is that you place the middle of your tonal range slightly below the mid point of your full latitude range. Reflected white should then come out around 68-70IRE. This then gives you further headroom for direct light sources such as lamps, the sky or specular reflections. In addition, video cameras tend to perform better in shadow and underexposure compared to highlights and over exposure, so it's generally considered better to be slightly under rather than slightly over.

But, all this theory is based on shooting some imaginary generic scene and as a result is a generalisation and may not be optimum in many lighting conditions. You also need to consider how S-Log works. Each stop is getting allocated roughly the same amount of data as the next. But when you consider that each brighter stop is has twice the brightness range as the previous stop then you need to consider that to some degree, each brighter stop is being recorded more highly compressed than the previous. This means that you can stretch and pull the darker parts of the exposure range more effectively than the brighter part, so you don't want your images to be too bright as this may not grade as well as the same scene exposed a little darker. Now on top of all this you need to consider noise. Underexpose too much and you will have issues with noise when you start lifting the shadow areas and darker parts of the image. So what I'm trying to say is that you don't want to overexpose and you don't want to underexpose. Where exactly you set your exposure will depend on the tonal range of the scene you are shooting. A dimly lit interior may have a much reduced range compared to a sunny exterior and this is where the skill of the operator comes in, knowing when it is desirable to push your exposure up or down.

Normally, mid grey at 38IRE works well and will put you in the right ball park. But if you don't have any direct light sources then you can probably lift mid grey a little, but in my opinion you must always, always protect your highlights. Small specula highlights or a small bright cloud may not show up on a small monitor or VF and might not register on the histogram or zebras so often it's good to have a bit of headroom in reserve.

Sadly I can't say you should always expose "x" at "y" as it's just not that simple. You have to judge for yourself depending on the scene you are shooting and the look you want to achieve. I would not get too hung up on white not reaching 100%, reflected white should only be at around 70%, it's direct light sources you need to watch.

Steve Kimmel · February 8th, 2012, 03:44 PM

Thanks Doug and Alister. I am finding exactly the same thing -- aiming for 38% for middle grey (using the spot meter on the F3) has worked pretty well overall. But, I ran into a problem in a very evenly lit, but darker room, where I should have pushed this up a bit. Not a big deal, but did have a bit of noise in post.

Right now I have several Colorista presets for various settings: preserve highlights, lift lows, neutral, etc. that I can apply to S-log footage based on the scene. I can then go and tweak as needed. I've found that this speeds up my workflow substantially.

Peter G. Johnson · February 8th, 2012, 08:44 PM

Quote:

Originally Posted by Peter G. Johnson

without the smart ass commentary because I can't relate to it.

Sorry, that's a little flippant. There's very few examples out there (before and after) to draw comparisons upon, so I'm doing it myself and I don't mind what people say. I really appreciate the feedback, positive and negative and I'll take all the criticism, but please use some non tech language and some pictures, screen shots (etc.)

Duke Marsh · February 8th, 2012, 09:40 PM

I agree with Alister that you can't just rely on one setting, like 38%.

Currently I have A port S-log going to the Samurai and 800%LUT with middle gray at 40 on a TV Logic monitor. I verify with the wave form setting. When the exposure looks right I turn it down another half a stop eyeballing it on the monitor. (The Prolock allows me to adjust fractions of a stop.)

This protects the highlights, which I find the most important thing. The mids and blacks you can adjust later. Blow out the highlights and they stay blown.

In post I first adjust the levels. Auto levels gives an idea where it should end up, but I adjust levels manually.

Then I adjust the middle of the gamma curve downward, which brings the colors back into the picture. If you try to do it with contrast you'll push the highlights back up to blow out.

If I need to I then might adjust colors, but I usually don't need to do it much if at all. If I do its usually a need to add a little more red saturation.

Its working for me. I don't know how anyone else is doing it and would be curious to hear what others are doing.

Doug Jensen · February 8th, 2012, 09:57 PM

I don't judge exposure (or color) just by how something looks on a monitor. That's just guessing. I use zebras and/or a waveform monitor for consistancy and accuracy. And with whites hovering around 68%, I have plenty of headroom and my highlights are well protected. That's how I do it.

Duke Marsh · February 9th, 2012, 06:38 AM

I do have zebras on set at 70 and 100, but find that more useful for exposing faces not for protecting highlights. I can always bring a slightly under exposed face back up if the highlights are protected.

I mean if you're indoors with your own lights properly set up lights there are no overpowering highlights to protect, then you just set exposure. Its the windows, sky, lights in scene and reflections that are going to jump up to bite you.

Doug Jensen · February 9th, 2012, 09:03 AM

I never use zebras on faces because skin tones vary too much from person to person, otherwise it just comes down to guessing. I know what white and gray are supposed to look like.

Alister Chapman · February 9th, 2012, 02:36 PM

I'm confused Doug. First you say:

I don't judge exposure (or color) just by how something looks on a monitor. That's just guessing. I use zebras and/or a waveform monitor for consistancy and accuracy.

Then you say:

I never use zebras on faces because skin tones vary too much from person to person, otherwise it just comes down to guessing. I know what white and gray are supposed to look like.

So how do you judge the exposure of a face? You say faces vary greatly, which I agree with, so there is no one level fits all exposure for faces, so zebras and other measurements are not telling you much, but then you don't use a a monitor to judge exposure as that's guessing. Please enlighten me as to how you do it then? Are you just exposing for your whites and then hoping everything else falls into place, I'm not so sure as your footage normally looks well exposed. There has to be some use of the monitor for exposure assessment happening?

Doug Jensen · February 9th, 2012, 03:59 PM

Hi Alister,

As you have suggested, I expose for white and then everything else falls into place. It's not like I can expose for whites, midtones, and blacks separately. There can be only ONE exposure, and I base that on whites. I've learned to resist second guessing the exposure by what I see on the viewfinder or LCD and to rely on what the zebras are telling. 99.9% they will be right.

In fact, I must confess that Paul Cronin was helping me shoot something a couple of weeks ago and I broke this cardinal rule. Now I have to grade the footage because I ignored what the zebras were telling me. First time I've made that mistake in a long time.

I compare it to a pilot flying in fog who doesn't believe his instruments, and thus flies into the ground upside down. When I trust my zebras it is always a safe landing.

Charles Papert · February 10th, 2012, 12:25 PM

I just spent a couple of weeks with the F800 and while it seemed perfectly nice, I was missing the range of s-log without doubt. A few times I was up against dappled light or hot backlit sun against blonde hair etc. in uncontrollable circumstances (was shooting a spoof of reality shows) and I was nervous about the degree of overall underexposure if I took the "expose to the right" philosophy too far. It might be a while before I take a 2/3" camera out in a run-and-gun situation again and hopefully by then s-log will be implemented into that body style also.

Doug Jensen · February 10th, 2012, 04:23 PM

Take a look at Survivor when the next season starts. The last few seasons have all been shot with F800/700 cameras and I think it is one of the best looking shows on broadcast TV, despite the fact that they are shooting in completely uncontrolled circumstances. The interviews especially just look great.

My only criticism of the way the show looks is that they let white water (ocean waves) blow out and clip too easily. Other than that, the show is a great showcase for what is possible with the F800/700.

Michael Carmine · February 11th, 2012, 11:14 AM

Dear Folks,

I have just gotten S-log and am shooting some camera tests. My customers are US network TV dramas and comedies. Can I shoot s-log to the card and let them grade it to match. They have been very happy with the cinegamma profiles to the card. Before someone yells in the night - can they grade the s-log on the card to be better than the cinegamma to the SxS card? All the post is done in Burbank and I don't want to ask them just yet. I dread carrying another box that needs batteries...

Any help would be greatly appreciated and if I have to I will get the Samurai box. Life is to short to get the KiPro.

February 8th, 2012, 01:15 PM	#33
Doug Jensen Vortex Media Join Date: Jan 2009 Location: Florida Posts: 3,442	Re: Does S-Log need to be graded all the time? Steve, I think the F3 and F800 would cut together seamlessly, but I've never actually had any reason to use them together on a multi-camera shoot. Even without taking the time to set them up side-by-side, I can already tell the the paint settings I use on each camera come pretty close to the same look. No surprise there, since I programmed them both to give me the standard look I like on any camera. To answer your other question, when I expose for S-LOG I want my bright whites at around 68% and/or my 18% gray card at 38%. __________________ Vortex Media http://www.vortexmedia.com/ Sony FS7, F55, and XDCAM training videos, field guides, and other production tools

February 8th, 2012, 02:11 PM	#34
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	Re: Does S-Log need to be graded all the time? Exposure is not something that is set in stone. The idea behind setting reflected mid grey at 38 IRE is that you place the middle of your tonal range slightly below the mid point of your full latitude range. Reflected white should then come out around 68-70IRE. This then gives you further headroom for direct light sources such as lamps, the sky or specular reflections. In addition, video cameras tend to perform better in shadow and underexposure compared to highlights and over exposure, so it's generally considered better to be slightly under rather than slightly over. But, all this theory is based on shooting some imaginary generic scene and as a result is a generalisation and may not be optimum in many lighting conditions. You also need to consider how S-Log works. Each stop is getting allocated roughly the same amount of data as the next. But when you consider that each brighter stop is has twice the brightness range as the previous stop then you need to consider that to some degree, each brighter stop is being recorded more highly compressed than the previous. This means that you can stretch and pull the darker parts of the exposure range more effectively than the brighter part, so you don't want your images to be too bright as this may not grade as well as the same scene exposed a little darker. Now on top of all this you need to consider noise. Underexpose too much and you will have issues with noise when you start lifting the shadow areas and darker parts of the image. So what I'm trying to say is that you don't want to overexpose and you don't want to underexpose. Where exactly you set your exposure will depend on the tonal range of the scene you are shooting. A dimly lit interior may have a much reduced range compared to a sunny exterior and this is where the skill of the operator comes in, knowing when it is desirable to push your exposure up or down. Normally, mid grey at 38IRE works well and will put you in the right ball park. But if you don't have any direct light sources then you can probably lift mid grey a little, but in my opinion you must always, always protect your highlights. Small specula highlights or a small bright cloud may not show up on a small monitor or VF and might not register on the histogram or zebras so often it's good to have a bit of headroom in reserve. Sadly I can't say you should always expose "x" at "y" as it's just not that simple. You have to judge for yourself depending on the scene you are shooting and the look you want to achieve. I would not get too hung up on white not reaching 100%, reflected white should only be at around 70%, it's direct light sources you need to watch. __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

February 8th, 2012, 03:44 PM	#35
Steve Kimmel Major Player Join Date: Aug 2010 Location: Philadelphia, PA Posts: 256	Re: Does S-Log need to be graded all the time? Thanks Doug and Alister. I am finding exactly the same thing -- aiming for 38% for middle grey (using the spot meter on the F3) has worked pretty well overall. But, I ran into a problem in a very evenly lit, but darker room, where I should have pushed this up a bit. Not a big deal, but did have a bit of noise in post. Right now I have several Colorista presets for various settings: preserve highlights, lift lows, neutral, etc. that I can apply to S-log footage based on the scene. I can then go and tweak as needed. I've found that this speeds up my workflow substantially.

February 8th, 2012, 09:40 PM	#37
Duke Marsh Regular Crew Join Date: Oct 2011 Location: OC, CA Posts: 65	Re: Does S-Log need to be graded all the time? I agree with Alister that you can't just rely on one setting, like 38%. Currently I have A port S-log going to the Samurai and 800%LUT with middle gray at 40 on a TV Logic monitor. I verify with the wave form setting. When the exposure looks right I turn it down another half a stop eyeballing it on the monitor. (The Prolock allows me to adjust fractions of a stop.) This protects the highlights, which I find the most important thing. The mids and blacks you can adjust later. Blow out the highlights and they stay blown. In post I first adjust the levels. Auto levels gives an idea where it should end up, but I adjust levels manually. Then I adjust the middle of the gamma curve downward, which brings the colors back into the picture. If you try to do it with contrast you'll push the highlights back up to blow out. If I need to I then might adjust colors, but I usually don't need to do it much if at all. If I do its usually a need to add a little more red saturation. Its working for me. I don't know how anyone else is doing it and would be curious to hear what others are doing.

February 8th, 2012, 09:57 PM	#38
Doug Jensen Vortex Media Join Date: Jan 2009 Location: Florida Posts: 3,442	Re: Does S-Log need to be graded all the time? I don't judge exposure (or color) just by how something looks on a monitor. That's just guessing. I use zebras and/or a waveform monitor for consistancy and accuracy. And with whites hovering around 68%, I have plenty of headroom and my highlights are well protected. That's how I do it. __________________ Vortex Media http://www.vortexmedia.com/ Sony FS7, F55, and XDCAM training videos, field guides, and other production tools

February 9th, 2012, 06:38 AM	#39
Duke Marsh Regular Crew Join Date: Oct 2011 Location: OC, CA Posts: 65	Re: Does S-Log need to be graded all the time? I do have zebras on set at 70 and 100, but find that more useful for exposing faces not for protecting highlights. I can always bring a slightly under exposed face back up if the highlights are protected. I mean if you're indoors with your own lights properly set up lights there are no overpowering highlights to protect, then you just set exposure. Its the windows, sky, lights in scene and reflections that are going to jump up to bite you.

February 9th, 2012, 09:03 AM	#40
Doug Jensen Vortex Media Join Date: Jan 2009 Location: Florida Posts: 3,442	Re: Does S-Log need to be graded all the time? I never use zebras on faces because skin tones vary too much from person to person, otherwise it just comes down to guessing. I know what white and gray are supposed to look like. __________________ Vortex Media http://www.vortexmedia.com/ Sony FS7, F55, and XDCAM training videos, field guides, and other production tools

February 9th, 2012, 02:36 PM	#41
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	Re: Does S-Log need to be graded all the time? I'm confused Doug. First you say: I don't judge exposure (or color) just by how something looks on a monitor. That's just guessing. I use zebras and/or a waveform monitor for consistancy and accuracy. Then you say: I never use zebras on faces because skin tones vary too much from person to person, otherwise it just comes down to guessing. I know what white and gray are supposed to look like. So how do you judge the exposure of a face? You say faces vary greatly, which I agree with, so there is no one level fits all exposure for faces, so zebras and other measurements are not telling you much, but then you don't use a a monitor to judge exposure as that's guessing. Please enlighten me as to how you do it then? Are you just exposing for your whites and then hoping everything else falls into place, I'm not so sure as your footage normally looks well exposed. There has to be some use of the monitor for exposure assessment happening? __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

February 9th, 2012, 03:59 PM	#42
Doug Jensen Vortex Media Join Date: Jan 2009 Location: Florida Posts: 3,442	Re: Does S-Log need to be graded all the time? Hi Alister, As you have suggested, I expose for white and then everything else falls into place. It's not like I can expose for whites, midtones, and blacks separately. There can be only ONE exposure, and I base that on whites. I've learned to resist second guessing the exposure by what I see on the viewfinder or LCD and to rely on what the zebras are telling. 99.9% they will be right. In fact, I must confess that Paul Cronin was helping me shoot something a couple of weeks ago and I broke this cardinal rule. Now I have to grade the footage because I ignored what the zebras were telling me. First time I've made that mistake in a long time. I compare it to a pilot flying in fog who doesn't believe his instruments, and thus flies into the ground upside down. When I trust my zebras it is always a safe landing. __________________ Vortex Media http://www.vortexmedia.com/ Sony FS7, F55, and XDCAM training videos, field guides, and other production tools

February 10th, 2012, 12:25 PM	#43
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	Re: Does S-Log need to be graded all the time? I just spent a couple of weeks with the F800 and while it seemed perfectly nice, I was missing the range of s-log without doubt. A few times I was up against dappled light or hot backlit sun against blonde hair etc. in uncontrollable circumstances (was shooting a spoof of reality shows) and I was nervous about the degree of overall underexposure if I took the "expose to the right" philosophy too far. It might be a while before I take a 2/3" camera out in a run-and-gun situation again and hopefully by then s-log will be implemented into that body style also. __________________ Charles Papert www.charlespapert.com

February 10th, 2012, 04:23 PM	#44
Doug Jensen Vortex Media Join Date: Jan 2009 Location: Florida Posts: 3,442	Re: Does S-Log need to be graded all the time? Take a look at Survivor when the next season starts. The last few seasons have all been shot with F800/700 cameras and I think it is one of the best looking shows on broadcast TV, despite the fact that they are shooting in completely uncontrolled circumstances. The interviews especially just look great. My only criticism of the way the show looks is that they let white water (ocean waves) blow out and clip too easily. Other than that, the show is a great showcase for what is possible with the F800/700. __________________ Vortex Media http://www.vortexmedia.com/ Sony FS7, F55, and XDCAM training videos, field guides, and other production tools

February 11th, 2012, 11:14 AM	#45
Michael Carmine Regular Crew Join Date: Mar 2009 Location: NYC/CA Posts: 34	Re: Does S-Log need to be graded all the time? Dear Folks, I have just gotten S-log and am shooting some camera tests. My customers are US network TV dramas and comedies. Can I shoot s-log to the card and let them grade it to match. They have been very happy with the cinegamma profiles to the card. Before someone yells in the night - can they grade the s-log on the card to be better than the cinegamma to the SxS card? All the post is done in Burbank and I don't want to ask them just yet. I dread carrying another box that needs batteries... Any help would be greatly appreciated and if I have to I will get the Samurai box. Life is to short to get the KiPro.