Exposing for background

[Eric Soto]

Hey everyone, just wanted to get a general idea of how one exposes the background in relation to the subject, in F stops. I understand that every situation is different but in general if people could give me ratios that they use it would be helpful.

 

Thanks everyone!

[David Mullen ASC]

Just depends on how you want the background to look compared to the foreground, assuming you have some ability to set the brightness of the foreground independently.

[Michael Rodin]

It's not that you light the background to some specific stop below/above key... it's more about lighting the space around the actor (your subject in foreground, in general) so that he stands out or "melts into" the background/middle ground to a needed degree. You always take the subject into account - i.e. if you want a dark haired/clothed person to stand out in frame, you might want to include an overexposed area behind them.

And unless you're shooting B&W, color relationships between fore- and background are just as important. With exposure you also control color saturation in BG, which gives you varying amounts of color contrast.

[Eric Soto]

Just depends on how you want the background to look compared to the foreground, assuming you have some ability to set the brightness of the foreground independently.

Right, well I guess what I am asking is how do you go about exposing for the background. Lets say you have your subject and the background. And you want the background to be 2 stops under the key on your subject. Assuming there is no sunlight coming through windows, how would one go about exposing the background. Would you do that first? and then light for the actor ? Also I've used false color to expose and I tried to keep the background one consistent color around 50 IRE, but I haven't found a way to get a good clean exposure of a background. Is this a method you would use? And lastly do you tend the expose background with direct light or bounce? Thanks!

[David Mullen ASC]

I guess I thought your original question was about balancing for a background daytime window, not just a background in a room.

 

When I shot film for "The Love Witch", all in hard light, this was more of an issue because (1) I had to use my light meter, and (2) with hard light, your key for the actors doesn't always hit the wall behind the actor, so the backgrounds needed separate "key" lighting on them. Also, I was following the convention of old movies of lighting the actors separately from the background. In that case, I often started out lighting the walls one-stop under key depending on what color they were painted. Since the movie was supposed to have strong colors, sometimes I put a spot on a wall that was at key exposure to make sure the color popped.

 

 

But modern movies generally aren't lit this way -- you light the space and the actor moves within that space. Sometimes, yes, you light an actor and find that the background is falling off too much and needs some extra light on it, especially in a dark-toned room like a room with dark wood panelling. Often I would just set that background light by eye though, and now with digital, by how it looks on the monitor. And you wouldn't light the room the same for day as for night, and in the scene itself, the number of practicals on or off, or whether a window shade is up or down, may be a story point, so there are no rules regarding how much light to put on a background wall.

[Eric Soto]

I guess I thought your original question was about balancing for a background daytime window, not just a background in a room.

 

When I shot film for "The Love Witch", all in hard light, this was more of an issue because (1) I had to use my light meter, and (2) with hard light, your key for the actors doesn't always hit the wall behind the actor, so the backgrounds needed separate "key" lighting on them. Also, I was following the convention of old movies of lighting the actors separately from the background. In that case, I often started out lighting the walls one-stop under key depending on what color they were painted. Since the movie was supposed to have strong colors, sometimes I put a spot on a wall that was at key exposure to make sure the color popped.

 

 

But modern movies generally aren't lit this way -- you light the space and the actor moves within that space. Sometimes, yes, you light an actor and find that the background is falling off too much and needs some extra light on it, especially in a dark-toned room like a room with dark wood panelling. Often I would just set that background light by eye though, and now with digital, by how it looks on the monitor. And you wouldn't light the room the same for day as for night, and in the scene itself, the number of practicals on or off, or whether a window shade is up or down, may be a story point, so there are no rules regarding how much light to put on a background wall.

Great thank you for the reply!

[Adam Frisch FSF]

Harris Savides ASC was always on point in these scenarios. Take a look at this scene from American Gangster where highlights on exterior are just overexposed the right amount without losing detail (guessing 1.5-2.5 stops, depending on if the sun is out or not).

 

https://www.youtube.com/watch?v=cXCMz340CRg

[Justin Hayward]

Harris Savides ASC was always on point in these scenarios. Take a look at this scene from American Gangster where highlights on exterior are just overexposed the right amount without losing detail (guessing 1.5-2.5 stops, depending on if the sun is out or not).

 

https://www.youtube.com/watch?v=cXCMz340CRg

Excellent example. Looks great. Such a good scene.

[Eric Soto]

Harris Savides ASC was always on point in these scenarios. Take a look at this scene from American Gangster where highlights on exterior are just overexposed the right amount without losing detail (guessing 1.5-2.5 stops, depending on if the sun is out or not).

 

https://www.youtube.com/watch?v=cXCMz340CRg

Thanks for the example. I've always admired the look of that film.

[Stephen Perera]

the simple answer is how do you want the background to look compared to your subject (person I guess in this case).....

 

if you want the background and the person to look 'the same' you have to 'balance' the light (stills photography term).....either with light shone onto the subject that's strong enough, or using reflectors etc...

 

simplistically....e.g. background is at f8 and person is at f4 then you need to put more light onto the subject until it reads f8 as well meaning the scene is balanced.

 

If you want the background to appear lighter as in the scene of the Denzel Washington movie (keeping the scene as the eye sees it more or less) then I would start by metering the outside and learn if the film stock/digital camera i am using holds those highlights within its dynamic range (detail in the blacks and detail in the highlights) and then start adding light onto the scene inside the cafeteria.....

 

ratios are for communicating to people on a real film set/location with lighting crew/gaffer of how much darker or lighter you want lights....

 

.....ultimately its all about perception and your vision.....its one of those how long is a piece of string questions....

 

...but what the hell do I know Im just a stills photographer enamoured with the art of filmmaking.....

Edited September 19, 2017 by Stephen Perera