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A scene solely with red lighting


Viggo Söderberg
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Next week I'll be filming a short film and one of the scenes will be taking place in a corridor at a night club. We've been working with the idea of having one light at the end of the corridor makes all these silhouettes and then there's a small encounter happening in the middle of the corridor. (Drunk girl falls over, guy picks her up. Her friends come over and help her away.)

I know red is a color that can look pretty blurry sometimes, so I was considering adding another light. Although, any light I tried to add didn't feel justified or ruined the look of the silhouettes which I quite liked. I also like to keep it quite dark, however in false color the skin doesn't even go green. Maybe I'm overthinking things but I was wondering if that was going to be too low.

Anyways, I'm just posting hoping to get some general feedback!

https://imgur.com/a/yzphd2G

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Do some tests and lets see the difference between all red and mixed.

I shot a lot of all red in the RLD in Amsterdam. They were all candid, all pushed and zone focused. Some all red.

These were all pushed 2 stops or so and high ISO, shot with a wide open  lens and cropped. So they are not representative of what the best would look like. They would have been sharper if I was not shooting in a local where photography was banned and you could get your ass kicked if caught. You have to walk and shoot!

Mixed light

De Wallen 48 2014 Daniel D.Teoli Jr : Daniel D.Teoli Jr. : Free Download, Borrow, and Streaming : Internet Archive

All red light

Prostitute Amsterdam 12-2014 Daniel D. Teoli Jr : Daniel D. Teoli Jr. : Free Download, Borrow, and Streaming : Internet Archive

Do some tests. That is your answer. Then let us know.

 

 

Edited by Daniel D. Teoli Jr.
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Because of the Bayer filter array in front of your sensor, if you shoot using only blue or only red light, the effective sensitivity of the sensor is reduced by 75%, so in order to compensate for that difference, you'd have to bump your gain, along with the accompanying noise, by two stops (for green, that's 50% or one stop).

In other words, if you're going for a monochromatic result and you're shooting digitally, use the most of the spectrum you can, shoot with a red LUT if you can, and save the final color decisions for grading.

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9 minutes ago, Tomasz Brodecki said:

Because of the Bayer filter array in front of your sensor, if you shoot using only blue or only red light, the effective sensitivity of the sensor is reduced by 75%, so in order to compensate for that difference, you'd have to bump your gain, along with the accompanying noise, by two stops (for green, that's 50% or one stop).

In other words, if you're going for a monochromatic result and you're shooting digitally, use the most of the spectrum you can, shoot with a red LUT if you can, and save the final color decisions for grading.

I don't like leaving decisions for later. I want red in the scene. Perhaps I could film it without the red gels, but what would a red LUT be doing exactly? How would I film it and how would I alter it in post to retain the color information of the blue and green channels while only promoting the red channel?

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1 minute ago, Stephen Sanchez said:

@Tomasz Brodecki, what if he just uses a 4x brighter light?

I figure that was what I was doing already. The false color image from the viewfinder doesn't know that I'm shooting only in red, it just measures proper exposure. So if I was lighting with normal strength from the lights the false color would be showing a lack of exposure because I'm starving it from the blue and green channels. But because I've used false color for my exposure I've boosted the strength in the lights in order for the red channel to compensate for the lack of green and blue in the image, meaning the red has proper exposure.

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5 minutes ago, Stephen Sanchez said:

@Tomasz Brodecki, what if he just uses a 4x brighter light?

Yes, there's always that third option, but it's not exactly the best one for the planet 😉 
Just to be clear — we're going to need more light for any scene intended for single-color result compared to an equivalent full-color one anyway (if we're going for a believable look of a single-color light source, because of the values that we will be substracting), but by using white we're left with more choices.
 

48 minutes ago, Viggo Söderberg said:

I don't like leaving decisions for later. I want red in the scene. 

There's a time and place for everything, and unless you have the colorist on set and/or performing final grading on the entire footage as you shoot, you will be making the ultimate color decisions in post production anyway, so the time on set is probably better spent focusing on the task at hand.
 

7 minutes ago, Viggo Söderberg said:

what would a red LUT be doing exactly? How would I film it and how would I alter it in post to retain the color information of the blue and green channels while only promoting the red channel?

The choice is up to you (or your DIT or your colorist, whoever prepares your LUT) as to how much you want it to use the blue and green values to be turned into reds and how much to be filtered out, or any specific point in between.

 

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The LUT route may be a good option. This is the time to test that theory. Set that fixture up in your house and do a pass with red light and then white light and try to grade it to match. Being that it's a monotone image, it may be easy to complete. And compare the two for quality.

My suspicion is that due to the large amounts of black in the scene (which I love btw) and already low levels, it will get quite nosy if relying on one channel for image reproduction. Plus your shooting tungsten which boosts the vacant blue channel more anyway.

I'm for completing a look in-camera, but there may be limiting factors you haven't seen. Be-it the camera or codec, etc. Say you throw more red at it and it ends up oversaturating, I don't know. A test will help identify that.

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What camera and codec will you be shooting? Digital or film? If digital, raw or 4:4:4 codec would be ideal. 4:2:2 or less could lead to artifacting.

Lighting-wise, how are you achieving the red color? Gels or RGB LEDs?

If you’re getting soft-looking images, one thing you can try is to dial in a less pure red color. In gel terms, instead of using Primary Red, try Fire Red which has a bit of yellow in it. This will help expose the green channel or green-sensitive film layer and help with sharpness. Then you can shift the color in post back to pure red if that’s the look you want.

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8 hours ago, Tomasz Brodecki said:

Yes, there's always that third option, but it's not exactly the best one for the planet 😉 
Just to be clear — we're going to need more light for any scene intended for single-color result compared to an equivalent full-color one anyway (if we're going for a believable look of a single-color light source, because of the values that we will be substracting), but by using white we're left with more choices.
 

There's a time and place for everything, and unless you have the colorist on set and/or performing final grading on the entire footage as you shoot, you will be making the ultimate color decisions in post production anyway, so the time on set is probably better spent focusing on the task at hand.
 

The choice is up to you (or your DIT or your colorist, whoever prepares your LUT) as to how much you want it to use the blue and green values to be turned into reds and how much to be filtered out, or any specific point in between.

 

But if I'm turning the green and blue values into red, will the information from the blue and green channels be retained? Will it not essentially be the same as just shooting red? I guess what I'm confused about is if I'm shifting it to red in grade then I'm taking out the green and blue values, so what would be the point in shooting it without the red color? Or am I misunderstanding how the camera shoots the image?

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5 hours ago, Stephen Sanchez said:

The LUT route may be a good option. This is the time to test that theory. Set that fixture up in your house and do a pass with red light and then white light and try to grade it to match. Being that it's a monotone image, it may be easy to complete. And compare the two for quality.

My suspicion is that due to the large amounts of black in the scene (which I love btw) and already low levels, it will get quite nosy if relying on one channel for image reproduction. Plus your shooting tungsten which boosts the vacant blue channel more anyway.

I'm for completing a look in-camera, but there may be limiting factors you haven't seen. Be-it the camera or codec, etc. Say you throw more red at it and it ends up oversaturating, I don't know. A test will help identify that.

Would it be beneficial to shoot at daylight perhaps?

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4 hours ago, Satsuki Murashige said:

What camera and codec will you be shooting? Digital or film? If digital, raw or 4:4:4 codec would be ideal. 4:2:2 or less could lead to artifacting.

Lighting-wise, how are you achieving the red color? Gels or RGB LEDs?

If you’re getting soft-looking images, one thing you can try is to dial in a less pure red color. In gel terms, instead of using Primary Red, try Fire Red which has a bit of yellow in it. This will help expose the green channel or green-sensitive film layer and help with sharpness. Then you can shift the color in post back to pure red if that’s the look you want.

I've geled the practical lamp in the shot and then boosting with a Skypanel out of frame.

I'll be shooting on the Alexa Mini, ProRes 444, C-Log.

It's the grading part I find most daunting. I'm not that experienced with grading so I don't know what I would need to so to shift the image to red in post.

Edited by Viggo Söderberg
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@Viggo Söderberg
If you want to shoot a scene in red, shoot it in red. 


Forget about colourists, LUTs and post-production, the best thing that you can do is to achieve the look that you're after on set with a light that is red.
In fairness, the images on your post look just a bit overexposed to me (maybe because I like contrast.

If it helps, I have shot plenty of scenes just with red (somehow!) and what I was seeing on set is what was in the final product. 

Examples on my reel (the train sequence basically)

Have a good day. 

 

Edited by Miguel Angel
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I see, Viggo.

Ultimately, if in doubt, shoot the way you are comfortable with. You'll learn with every setup.

All these concerns arise from different points of views on imaging. Every shooter has different values and different approaches. Some lean more towards artsy without a concern over the capture technology, some operate under arbitrary "rules" such as "tungsten-only" or "raw-only," some consider quality of image first. My favorite photographer, Karl Taylor, is probably the only human in the world that considers every individual factor before capture.

Every shooter finds their own priority priorities when it comes to imaging. Since we work in the arts, there's no strict right or wrong way to work.

To answer your question. Yes, if trying to expose all channels for best possible data for your camera, 5600k light source is best, since 3200k WB boosts the blue channel. This is if you're going to color it in post.

Coloring in post is easy. I'm not a colorist, but I used to do graphic design, and I've done images like that where I'll place the desired color over the footage then use "multiply" or "screen" to apply color information. Ask a colorist for their opinion. And again there will be different solutions from them as well.

6 hours ago, Viggo Söderberg said:

But if I'm turning the green and blue values into red, will the information from the blue and green channels be retained? Will it not essentially be the same as just shooting red? I guess what I'm confused about is if I'm shifting it to red in grade then I'm taking out the green and blue values, so what would be the point in shooting it without the red color? Or am I misunderstanding how the camera shoots the image

You're confusing image capture with image processing. The initial capture from the sensor happens on all three pixels (RGB). The resulting data is converted to an image file. At that point you can adjust the image. He's talking about giving your camera the most data for it to spit out a cleaner image.

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A deeply colored-lit shot would not have high exposures if you want to retain the saturation, so don't worry about the waveform not showing a high signal level -- in monochrome, you'd expect a red-lit face to be more like 18% grey at the brightest, probably a stop under that.

If you want a face to be lit red, light it that way.  Try try and shoot 444 or raw if possible. Pull any diffusion filters, keep the light at a contrasty angle to improve sharpness.

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8 hours ago, Viggo Söderberg said:

I've geled the practical lamp in the shot and then boosting with a Skypanel out of frame.

I'll be shooting on the Alexa Mini, ProRes 444, C-Log.

It's the grading part I find most daunting. I'm not that experienced with grading so I don't know what I would need to so to shift the image to red in post.

Then I think you’ll be fine lighting as Miguel and David suggest. Definitely don’t shoot it with white light and grade it red! That’s just unnecessary.

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  • 2 weeks later...
On 2/1/2021 at 5:40 PM, David Mullen ASC said:

A deeply colored-lit shot would not have high exposures if you want to retain the saturation, so don't worry about the waveform not showing a high signal level -- in monochrome, you'd expect a red-lit face to be more like 18% grey at the brightest, probably a stop under that.

If you want a face to be lit red, light it that way.  Try try and shoot 444 or raw if possible. Pull any diffusion filters, keep the light at a contrasty angle to improve sharpness.

 

On 2/1/2021 at 6:13 PM, Satsuki Murashige said:

Then I think you’ll be fine lighting as Miguel and David suggest. Definitely don’t shoot it with white light and grade it red! That’s just unnecessary.

Have been busy with shooting but thank you for the responses! In the end I did shoot it in red and I tried keeping in mind not going by false color. It wasn't a very significant scene but I really liked the results so thank you for input!

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3 minutes ago, Viggo Söderberg said:

 

Have been busy with shooting but thank you for the responses! In the end I did shoot it in red and I tried keeping in mind not going by false color. It wasn't a very significant scene but I really liked the results so thank you for input!

Congrats! Would love to see it when the film is completed.

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