Exposing for the look

[Tiago Pimentel]

Hey guys 

 

I was curious how you are handling exposure with digital cameras, particularly with dark scenes involving people. Most cameras will render great skin tones if skin is exposed for 70IRE, but can mess everything up if set is lit and exposed to the end result. So my question is: are you exposing skintones for 70IRE or close and then pull everything down in post (a nightmare for any gaffer because of all the flagging he'll be doing) or do you expose exactly how you want it to look? Or maybe something in the middle? 

 

Thanks! 

[Stuart Brereton]

Why would pulling your exposures down in post require flagging to be done on set?

I generally expose exactly as I want it to look. There are many people who will be watching dailies, and not all of them are overly blessed with imagination. If a scene is dark when it should be light, or light when it should be dark, questions will be asked. It's much better to expose as you want your images to look, that way there is no confusion about your intent. 

[Tiago Pimentel]

13 minutes ago, Stuart Brereton said:

Why would pulling your exposures down in post require flagging to be done on set?

I generally expose exactly as I want it to look. There are many people who will be watching dailies, and not all of them are overly blessed with imagination. If a scene is dark when it should be light, or light when it should be dark, questions will be asked. It's much better to expose as you want your images to look, that way there is no confusion about your intent. 

Hey Stuart. Yeah, I forgot about dailies, they are always the main "issue". I was mentioning flagging because if you light a dark scene and expose it to have the skin tones falling where the camera is "expecting" them, then a lot more light is needed and, as such, a lot of flagging to keep ratios clean. 

 

But what you said makes absolute sense. But not all cameras deliver clean footage in a dark scene. 

[David Mullen ASC]

Sure a camera can deliver clean blacks in a dark scene. If you are shooting a bright day exterior at a low ISO, does the noise increase if you stick the lens cap on and the frame goes black?

[Tiago Pimentel]

Hey David. In my case, with my camera, I feel like I can't really push saturation too much if the image is dark. Otherwise it will introduce that horrible chroma noise. But in dark scenes, saturation should be low anyway, so... I was just curious as to how other DPs were approaching dark scenes. One question: if you're using a camera rated at 800iso, would you use 200 or 400 for a dark scene? 

Edited January 19, 2020 by Tiago Pimentel

[Stuart Brereton]

13 hours ago, Tiago Pimentel said:

I was mentioning flagging because if you light a dark scene and expose it to have the skin tones falling where the camera is "expecting" them, then a lot more light is needed and, as such, a lot of flagging to keep ratios clean. 

I've never noticed that creating contrast is any more difficult with bright scenes as opposed to dark scenes. It may be that it appears that way to the eye because of the way it adapts to different levels of illumination. I don't think I've ever had to spend extra time flagging lamps because I was lighting to f4 rather than f2.

4 hours ago, Tiago Pimentel said:

if you're using a camera rated at 800iso, would you use 200 or 400 for a dark scene? 

If I have enough light, I'll often switch to 400 iso to get some extra detail in the shadows and clean up noise

[Andy Jarosz]

I think the key is, no matter what you do, to make sure everyone in the chain that deals with the image knows what you're doing.

You will get cleaner images and thicker negatives if you shoot as you mentioned in your original post, by exposing to a certain IRE and bringing it down in post. By doing that, you're "spreading" that data over more of the available dynamic range. You'll of course lose some when you go to grade the image, but it'll give you more flexibility as you do--you'll find you can push the image more.

However, as others mentioned, if a client is going to see the raw footage, or you need to delivery ASAP without grading, than of course expose for the look.

 

Edited January 20, 2020 by Andy Jarosz

[David Mullen ASC]

In dramatic fiction, an actor's face will often not be at 70 IRE within a space, it all depends on where they are in the room -- brighter when they are by a daytime window, darker when they move away from it, etc.

IF you are shooting at an ISO that gives you an acceptable noise level, then you should be fine with having dark areas in the scene (shadows, dark clothing, etc.) But you will get more noise as soon as you try and manipulate it in post unless you are recording a very high-quality codec (low compression, high bit rate, decent color subsampling rate), and even then, you'll get more noise as you lift anything because that's the same thing as increasing the ISO in that area.  So don't "push" things, shoot them in camera the way you want them to look.  And it's always safer to not underexpose a dark scene too much, save some darkening for post, or drop the ISO to darken the shot rather than close down the iris.

[Alexander H Davis]

Are you talking about input or output IRE? Log or 709? 2020? What Camera? Sony has a 33% grey whereas most others are around 18-22%. Every camera is different and opinions vary on this subject. 

IMO if you expose your skintones (fair, white skin) for 709 they will generally look bright and overexposed (if viewed on an LCD, LED, or other display that is beaming light at you from powered diodes) if at 70% IRE and generally speaking for beauty, commercial and other advertising formats, this is what is expected of your white skintones. (This is why, in my opinion, when viewing cinematography as an artform, it must be done in a projection house, as your eyes will be more comfortable, and you will see the work as intended.) As for darker skintones, you can expect to deal with a lot more reflected light than with white skin, which is generally not too reflective unless coated with oil or sweat. This brings into question what type of color are you looking for when talking about skintone, and generally varies from application to application. With darker skin, more care needs to be taken to stray light hitting your actors skin, and tungsten lamps are generally employed here to gain a fuller spectrum of true light. If you use low cost LEDs from China, the chances they will have a lot of green in them is very high, and even if the luminance of the skin is at 70%, this will still not be a true "skintone" as it will be reflecting a lot more green light back at the camera, which actually has twice as many green pixels as red or blue, so you will get a lot of green contamination in the skin you were not aware was present on the day.

As David says, in dramatic fiction, professional cinematographers tend not to worry as much about "technical skintones" and worry more about the general mood of the scene, which often times helps the audience to understand the reality of the situation they are looking at. This is where a good understanding of how to control your contrast ratio effectively and efficiently is a great skill to have.  

If you are shooting a comedy, you might want to push those skintones a bit higher and keep them there in a lot of scenarios with more front light to make sure you get the expression and the comedy of the action well lit, but in dramatic narrative, you have more of a responsibility to the audiences suspension of disbelief. You have to trick the viewer into thinking this is how the scene looks to the naked eye, not some camera tech that I employed to make sure you as the audience know I know what I'm doing with a camera and the latest tech. 

When lighting for skin, I generally look for who my character is rather than adhering to a technical set of guidelines and work with direction and contrast more than worrying about what is at 70%. This will help you create dynamic lighting scenarios and allow your actor to move in the space freely, creating more and more suspension of disbelief, and your audience will appreciate that because the performances will be better.

Another great way to do this on a low budget is to shoot a safe negative at all times. Only light your scene for 7-9 stops of range as 709 is only 5-6 stops of output. This will allow you a lot of room to move around in the grade and help reduce your noise because you are keeping the signal within the middle of the signal to noise ratio. 

Keep doin what you love!