FEATURE REQUEST: Ed Lachman Zone (EL Zone) Exposure System

The half stops are a necessary course correction. Mid grey is a singular point tonally, the only part of the image that’s mid grey in LogC would be the 10 bit value 400. For grey to be visible as a full stop, EL uses a half stop over/under to represent mid grey necessitating the half stops on either side. The alternative would be mid grey as point 400 or it represents two stops.

Good Luck

EL: “When you move out to extremities of the body, therefore, you can just make those two-stop values – minus four can represent two stops, and so on."

I don't quite understand, can someone please explain?

It sounds like he expects shooters to recalculate the value of the stops at the "extremities", for cameras which don't conform to the existing scale. So in his example, -4 isn't two stops away from crushed blacks, it's more like four. But since -6 and +6 are no longer absolute measures, there's no way to see, graphically, when the sensor is clipping, without some additional indicator on the screen. And recalculating the value of stops at the edges becomes more complicated as ISO values change the distribution of stops above and below middle grey.

Ah I see, thanks.

This video shows the EL Zone in operation on the Small HD monitor.

Here it is on the Sigma Fp.

I can see why this system appeals. It’s a way to know what’s a stop over, two stops over three stops under your given exposure.

The problem is that it’s misleading. Just like if you use a reflected light meter the meter readings are thrown off by the reflectivity of the subject being photographed.

So it’s not REALLY a stop over as measure by footcandles. It’s REFLECTING a stop more (or absorbing a stop more)

Look at the examples on a persons face with dark hair. The face is all within a stop and yet the hair is a few stops under that. Now if you accurately metered that, the hair isn’t three stops darker than the face. It REFLECTS less light sure and you could equate that to a colour coded system that measures in stops but that’s not the same thing.

False colour is great. Turning it into “stops” is misleading. Sure it accurately shows what the camera is reading and you can understand the differences based on stops shown by colour but that still takes understanding exposure theory to understand that dark hair lit with the same amount of light as a face can be three stops different in what it reflects.

Then on top of that what do you do with a scene that is beyond 12 stops or less than 12 stops?

If anything maybe adding in more colours into the existing false colour is more useful in my view.

I think the most important things to know in evaluating scene contrast and therefore exposure is…

1. What is clipping and unrecoverable?
2. What is underexposed beyond recovery?
3. Where is the mid point?

False colour does these three things very well.

JB

So it’s not REALLY a stop over as measure by footcandles. It’s REFLECTING a stop more (or absorbing a stop more)

The EL Zone system turns the camera display into a spotmeter, reflective and incident readings are a different animal.

Good Luck

So it’s not REALLY a stop over as measure by footcandles. It’s REFLECTING a stop more (or absorbing a stop more)

The EL Zone system turns the camera display into a spotmeter, reflective and incident readings are a different animal.

Good Luck

I get that Howie. Hence “reflected”

And just like with a spot meter, the numbers are going to be wrong for anything you point it at except for an 18% grey card if you’re trying to turn your camera into a reflected light meter.

JB

Looks to me that it's absolutely great to see contrast ratios around middle grey, on faces ect in an intuitive way. Also to maintain consistency more precisely.
It is not the same as False Color and I don't think it wants to replace it.

Walter Volpatto, who posts here, did a great Master Class and talked about how on set a Director of Photography, perhaps due to film, only exposes for around 7 stops of light on set.

He explains how, as a colorist, he rolls off the extras stops of exposure beyond 7 stops (or 8 stops for HDR).

Here's a clip of it.
https://streamable.com/nte2zo

Here's the Youtube Video on it. The whole video is great.
1:01:52

If the EL zone shows from -6 to +6, then this would easily cover the common number of stops that are exposed for on set. Those extras stops are going to be rolled off in post.

EL-Zones-legend-FDTimes.jpg (34.61 KiB) Viewed 9245 times

These practices, along with the EL Zone, would allow any Blackmagic camera user to expose to the practice to make it more in line with Post Production is done.
It's not meant to be a replacement for False Colors, it would be an addition option for those who wish to use it, and Zebras can cover for areas that are clipping.

I've been tested too and don't see anything either.
And then, if you want to find out if you are good to grade, the test where you arrange swatches of colours according to their hue is the better one.
BTW, my ex-wife was one of those rare women. She always said that she's grateful for the fixed array of traffic lights

Sorry for the derail.

Just a thought on what really matters:

Most of what we see in a scene in a traditional theatre projection is going to fit within 50 nits. Most LCD and even OLED HDTV televisions are using 100 nits to display most of their image. Some 4K OLED televisions allow for 203 nits for most of the image but peak intensity can be 1000 nits. Monitors can go higher. Digital Dolby tops out at 10000 nits.

What is a practical lowest discernible black above 0 in these different scenarios? If we assume a starting black of 1 nit, then we hit 50 nits in <6 stops, 100 nits in <7 stops, 203 nits in <8 stops. So Walter’s range is appropriate for most of the contents of a scene even in 4K television using HDR. But the 4K OLRD television can display almost 10 stops at 1000 nits. So it seems to me you want your camera to be as capable; so the limitations of Ed’s scale may not be consequential, but I still prefer the False Colour that handles 12 or more stops.

Feel free to shoot down this train of thought because these stops really depend upon the starting value which may not be the 1 nit I suggested.

Just a thought on what really matters:

Most of what we see in a scene in a traditional theatre projection is going to fit within 50 nits. Most LCD and even OLED HDTV televisions are using 100 nits to display most of their image. Some 4K OLED televisions allow for 203 nits for most of the image but peak intensity can be 1000 nits. Monitors can go higher. Digital Dolby tops out at 10000 nits.

What is a practical lowest discernible black above 0 in these different scenarios? If we assume a starting black of 1 nit, then we hit 50 nits in <6 stops, 100 nits in <7 stops, 203 nits in <8 stops. So Walter’s range is appropriate for most of the contents of a scene even in 4K television using HDR. But the 4K OLRD television can display almost 10 stops at 1000 nits. So it seems to me you want your camera to be as capable; so the limitations of Ed’s scale may not be consequential, but I still prefer the False Colour that handles 12 or more stops.

Feel free to shoot down this train of thought because these stops really depend upon the starting value which may not be the 1 nit I suggested.

In Walter's example, he is only using 8 stops total for HDR. That's -4 to +4. The EL Zone system covers a total of 12 stops (-6 to +6). Later in the video Walter answers a question that states he is only using 600nits for HDR out of 1000 nits.

Again it isn't meant to replace False Color. False Color is more of a camera by camera tool, while EL Zone would be more of an more universal tool.

Are the - 3 to -6 and +3 to +6 important to be by stops?

Why not just scale them to what the camera has, and keep the center part as it is.

I would keep them absolute as then you can have them line up with the same number of wheels in HDR Panels. (6).

Black, Shadow, Dark, Light, Highlight, Spectacular.

Then use Zebras to show the complete edges.

Interesting.

I work in stops. This makes sense to me.

+1 for cameras and monitors. I've got it in a Sigma FP and a SmallHD which I'm using with an a7S3 and I think it's brilliant. It would be a wonderful addition to BM products.

+1 for cameras and monitors. I've got it in a Sigma FP and a SmallHD which I'm using with an a7S3 and I think it's brilliant. It would be a wonderful addition to BM products.

I hope other monitors manufacturers add it.

One thing I notice is that EL Zone has dark skin below middle gray, whereas False Color has it AT middle gray.

And both show it in green.

Subjective calls? Or is someone doing it wrong?


(But they both seem to have light skin using yellow at MG+1. I dunno.)

One thing I notice is that EL Zone has dark skin below middle gray, whereas False Color has it AT middle gray.

And both show it in green.

Subjective calls? Or is someone doing it wrong?


(But they both seem to have light skin using yellow at MG+1. I dunno.)

Dark skin is supposed to be at -1 Middle Gray. The EL Zone is correct.

Thanks, Shaheed.

Thanks, Shaheed.

Here's a video where Walter talks about it.

An hour and 3 mins in. For record, Walter did Queen Sugar which looks great.

Yes. Please add this to to the false color plug in Davinci Resolve as well!!!

+1

I found this on Utube:

I actually created a 33 point lut which I brought into my bmpcc 4k. Since I record in film log anyway all I have to do is dedicate one of the function button to display the lut thus I can have the EL Zone displaying on both monitor and LCD and when I am happy with exposure, remove the lut by pressing on the function button again.

Granted I still have to test this since I just installed it and it does not have the legened right there on the screen but it is a work around without having to spend $1000 + on a smallHD monitor

I found this on Utube:

Interesting, thanks for sharing. Will test the DCTL in the next weeks.

I found this on Utube:

I actually created a 33 point lut which I brought into my bmpcc 4k. Since I record in film log anyway all I have to do is dedicate one of the function button to display the lut thus I can have the EL Zone displaying on both monitor and LCD and when I am happy with exposure, remove the lut by pressing on the function button again.

Granted I still have to test this since I just installed it and it does not have the legened right there on the screen but it is a work around without having to spend $1000 + on a smallHD monitor

Could you share your 33 point LUT?

I tried attaching the .cube file but the site will not let me.

I can post it on google drive folder and share with you or send to your email.

Here is a link to a folder on my google drive where you can find the Lut:

Here is a link to a folder on my google drive where you can find the Lut:
https://drive.google.com/file/d/1_HkEUn ... drive_link

Thanks!

They added El Zone to the Atomos Ninja.

We need this in the Blackmagic Cameras & Video Assist.

tested it today with Pocket 4k and it is on the money accurate. A lightmeter read out on gray card exposed at 400 ISO |24F showed exactly the same F-stop the camera registered. I am so impressed! The only thing that I wish we could do is put on the screen the actual Legend | Map of colors

It’ll come to Nobe OmniScope, BTW.

tested it today with Pocket 4k and it is on the money accurate. A lightmeter read out on gray card exposed at 400 ISO |24F showed exactly the same F-stop the camera registered. I am so impressed! The only thing that I wish we could do is put on the screen the actual Legend | Map of colors

Any way to re-share the Google Drive link?

tested it today with Pocket 4k and it is on the money accurate. A lightmeter read out on gray card exposed at 400 ISO |24F showed exactly the same F-stop the camera registered. I am so impressed! The only thing that I wish we could do is put on the screen the actual Legend | Map of colors

Any way to re-share the Google Drive link?

If you watch the video, it shows you how to make the LUT to put on your monitor.

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A good video comparing RED's Gio Scope vs EL Zone System.

I would love to see EL Zone System in Blackmagic cameras and in Resolve.

Or in Nikon's cameras, aka Red.

Although the EL Lachman Zone System is implemented via Dado Valentic’s Look Designer in Davinci Resolve, I vote +1 to have it natively in Davinci Resolve.

Although the EL Lachman Zone System is implemented via Dado Valentic’s Look Designer in Davinci Resolve, I vote +1 to have it natively in Davinci Resolve.

What is this?

Although the EL Lachman Zone System is implemented via Dado Valentic’s Look Designer in Davinci Resolve, I vote +1 to have it natively in Davinci Resolve.

What is this?

https://colourlab.ai

Although the EL Lachman Zone System is implemented via Dado Valentic’s Look Designer in Davinci Resolve, I vote +1 to have it natively in Davinci Resolve.

What is this?

https://colourlab.ai

Here is the official site
https://www.elzonesystem.com/

and an interesting interview with the developer with a detailed description about the EL Zone System.

+1 for cameras and monitors. I've got it in a Sigma FP and a SmallHD which I'm using with an a7S3 and I think it's brilliant. It would be a wonderful addition to BM products.

I hope other monitors manufacturers add it.

Átomos has implemented the EL Zone System on their later displays too.

As will Nope OmniScope soon.

In relation to the EL Zone System limitation of 12 stops, Mr. Ed Lachman has said the following in the comment of the article below:
“There is no problem in extending the exposure range in the EL Zone System in stops for ARRI Alexa 35 or for any other camera manufacturer through in-camera representation or using a Small HD. It won't add more colors, which would only make it less distinguishable and lose the simplicity of the mid-tones, where it is most important. The whole concept and design of the EL Zone System is for cinematographers in the field with its values of light in stops to distinguish contrast and exposure. In the areas of the over- and under-exposure, where more stops are needed, I will be instituting a system similar to zebras to represent the amount of stops that would hold detail in the over or under areas. Thanks for everybody's comments and your article. As camera sensors have become more sensitive, it has always been in my thoughts and I hear you. And of course, the EL Zone System has to recognize whatever the latitude of the sensor is that it is representing.”
https://www.newsshooter.com/2023/03/06/ ... ou-use-it/

+1

I asked Ed Lachman on his forums about getting EL Zone system on Blackmagic cameras and he replied with this.

This is one of our goals with the EL Zone System—to have it available from camera to monitor to post production. We have been in discussions with Blackmagic and will certainly post any updates as we have them.


Thanks for your question and support.

In relation to the EL Zone System limitation of 12 stops, Mr. Ed Lachman has said the following in the comment of the article below:
“There is no problem in extending the exposure range in the EL Zone System in stops for ARRI Alexa 35 or for any other camera manufacturer through in-camera representation or using a Small HD. It won't add more colors, which would only make it less distinguishable and lose the simplicity of the mid-tones, where it is most important. The whole concept and design of the EL Zone System is for cinematographers in the field with its values of light in stops to distinguish contrast and exposure. In the areas of the over- and under-exposure, where more stops are needed, I will be instituting a system similar to zebras to represent the amount of stops that would hold detail in the over or under areas. Thanks for everybody's comments and your article. As camera sensors have become more sensitive, it has always been in my thoughts and I hear you. And of course, the EL Zone System has to recognize whatever the latitude of the sensor is that it is representing.”
https://www.newsshooter.com/2023/03/06/ ... ou-use-it/

But this is kind of the problem with this system. So if you’re outside that range you have zebras?

Modern cameras do more than 12 stops. So then you loose the point because at say 16+ stops like an A35 can do you don’t have fine discretion over those stops at the extremes. I routinely use false colour on Alexa and Blackmagic to look at what’s red and what’s yellow. Everything else below that is gradeable anyway so I don’t need to know if the key is two stops bright than the fill. That’s what a light meter is for.

I’m also unsure what happens when you bend the ISO. In native mode you might have say 5 stops over but if you alter the midpoint (ISO CHANGE) you all of a sudden have 8 stops over. Which scale do you use now and how is that represented in this scheme?

I understand the appeal of this system, but I can’t see how you implement it without causing even more confusion.

JB

In relation to the EL Zone System limitation of 12 stops, Mr. Ed Lachman has said the following in the comment of the article below:
“There is no problem in extending the exposure range in the EL Zone System in stops for ARRI Alexa 35 or for any other camera manufacturer through in-camera representation or using a Small HD. It won't add more colors, which would only make it less distinguishable and lose the simplicity of the mid-tones, where it is most important. The whole concept and design of the EL Zone System is for cinematographers in the field with its values of light in stops to distinguish contrast and exposure. In the areas of the over- and under-exposure, where more stops are needed, I will be instituting a system similar to zebras to represent the amount of stops that would hold detail in the over or under areas. Thanks for everybody's comments and your article. As camera sensors have become more sensitive, it has always been in my thoughts and I hear you. And of course, the EL Zone System has to recognize whatever the latitude of the sensor is that it is representing.”
https://www.newsshooter.com/2023/03/06/ ... ou-use-it/

But this is kind of the problem with this system. So if you’re outside that range you have zebras?

Modern cameras do more than 12 stops. So then you loose the point because at say 16+ stops like an A35 can do you don’t have fine discretion over those stops at the extremes. I routinely use false colour on Alexa and Blackmagic to look at what’s red and what’s yellow. Everything else below that is gradeable anyway so I don’t need to know if the key is two stops bright than the fill. That’s what a light meter is for.

I’m also unsure what happens when you bend the ISO. In native mode you might have say 5 stops over but if you alter the midpoint (ISO CHANGE) you all of a sudden have 8 stops over. Which scale do you use now and how is that represented in this scheme?

I understand the appeal of this system, but I can’t see how you implement it without causing even more confusion.

JB

I think Walter Volpatto sums it up best: most DPs are only working with 7 Stops for SDR and 8 Stop for HDR going the final display regardless of camera. Those extra stops are rolled off anyway.

Walter talks about it at around 1 hour and 1 minutes.
Go to 1:01:00

The whole system is relative to the middle Grey point. The system isn't certainly an end all be all for everyone. No one is forced to use it. The problem with false color is the color settings are not standardized. One camera's color representation it totally different from another's. With this the colors aren't going to change.

Those extra stops are rolled off anyway.

Well I think those stops are important. Even if they are “just rolled off”

That’s a choice in grade. Not in capture.

And the whole point of this different system is to track all this right?

JB

Those extra stops are rolled off anyway.

Well I think those stops are important. Even if they are “just rolled off”

That’s a choice in grade. Not in capture.

And the whole point of this different system is to track all this right?

JB

As long as those stops aren't clipping, they are there.

It's more like this new system is to standardize exposure across cameras as well as use the frame as a spot meter digitally with focus on the skin tones. It is a way to save exposures of a camera still that you can use and repeat later. Unlike False color, you can look at the frame and know exactly how many stops you need to adjust. As far as I know, you can't use a false color system and decipher how many stops you need to go up or down and then use that information for a light meter, as it's using that particular camera's IRE. This isn't designed to replace using Zebras or any other tools. It's just another tool to use.

+1


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