How to expose (meter) for silhouettes and what Exposure Index (EI) would be most suitable for digital cameras?

[silvan schnelli]

How would you go about metering and exposing for a scene with a silhouette, such as in this cropped frame from Alfred Hitchcock's Vertigo? I often find that exposing for the background to be middle gray does the trick, but I'd much rather be certain on how to do it. What would I choose to expose to be middle grey, should I try to correctly expose it and try find a source that most resembles it? Also how would you go about choosing the distribution of the highlight and shadow latitude, I understand that this obviously depends on how I want the scene to look and the scene in itself, but do most people aim for? Do you tend to try and keep details in the shadows of the silhouetted figure?

 

In this scene for example, at least to me, there seems to be high distribution in both the highlight and shadow latitude, so perhaps a balanced EI would be a better choice. However,  I suppose since the figure is meant to be silhouetted anyways, so perhaps we do not want shadow details and rather have more highlight information for the neon sign, hence a low EI would be better? I guess this would also improve the SNR.

I aware these are a lot of questions, so thank you for taking your time and reading this.

[silvan schnelli]

Ups I meant to say "hence a high EI", not Low EI for more highlight detail and then "however this would lead to a worse SNR", not better SNR. Apologies

[David Mullen ASC]

There are all kinds of brightness levels possible for the background of a silhouette. Silhouettes against a saturated color though tend to be exposed at 18% grey or darker to preserve the color.

 

[David Mullen ASC]

Here’s a silhouette shot I did for “Big Sur” - this was digital so I didn’t use my meter but if I did for film, I might spot meter the shaft in front of his face and set it about 1/2-stop or 1-stop over 18% gray.

[David Mullen ASC]

Generally with a silhouette shot you aren’t fighting to get enough exposure so there usually isn’t a reason to use a high ISO on a digital camera but I wouldn’t necessarily use a very low ISO either. Anything within a range of the recommended ISO is fine. Just expose for the mood you want and don’t clip any highlights.

[silvan schnelli]

@David Mullen ASCFirst and foremost thank you for the replies.

So in general how many stops under do you tend to aim for the silhouettes to be, do you ever try to keep them at a certain scene to preserve some detail or to perhaps have a better SNR, so the quality of the silhouettes aren't as noisy, or do you just naturally let them fall into a certain exposure level. You also mention that you would meter for the shaft of light and then set it one stop over, is that just intuitive that you can see that that shade is roughly one stop over middle grey. 

I also in general I had a question, l if we take the Alexa mini with its 7.8 overexposure latitude and 6.7 underexposure latitude to film a contrasty scene such as in "Vertigo" where you would want detail in the bright neon sign and also detail in the shadows, where do you find that your shadows and highlights fall into (or such as in your example from "Big Sur"). I remember seeing an answer from you on another forum topic where you mentioned that people used to light scenes within 11 stops but now its different. Do you find yourself often having elements in a scene which are found at the lower and upper bound of the dynamic range and does it even make sense to light this way, to try to reach the limits of the dynamic range?

Another example perhaps, a very contrasty scene where the whole set is practically in darkness and you would still want details in the shadows, but at the same time there is a bright practical in the scene.

Thank you

[David Mullen ASC]

By definition, a silhouette is black so I wouldn't meter it, I'd just make it as black as possible -- to help, I'd try to make the background brighter so that the shadows fall off to black faster. I'd surround the foreground with negative fill. 

If I were shooting film, I'd only meter the shadow if I were in a situation where I couldn't control the lighting as well and wasn't sure it would fall to black. On a film print, a medium-toned object falls to black about 4-to-5-stops under but with digital correction, if you get close enough you can crush the shadows down.

I don't meter digital either so in terms of lighting and exposing a shot like in "Vertigo", I'd set the exposure for the neon sign (and if it were really too hot, I might darken it with some ND gel or netting or a neon dimmer) and balance the interior for the level of detail I wanted.

Remember, you are lighting digital for the display gamma, generally unless you are going for an HDR release, you have more information in the recording than in the displayed image.

I actually had a small set where I asked the art department if I could get a neon sign out the window like the one in "Vertigo" and they did it! But this is digital, you can set all the levels by monitor basically using dimmers on the lights.

 

 

[David Mullen ASC]

Silhouettes aren’t that hard - I just asked my wife to take a picture of me with my iPhone:

[silvan schnelli]

@David Mullen ASC Thank you a lot for the thorough responses. It seems that both you and your wife are amazing cinematographers. 

[Steven West]

 

On 11/3/2023 at 6:50 AM, silvan schnelli said:

Also how would you go about choosing the distribution of the highlight and shadow latitude, I understand that this obviously depends on how I want the scene to look and the scene in itself, but do most people aim for? Do you tend to try and keep details in the shadows of the silhouetted figure?

I’m not sure this is the answer you are looking for, but, regarding choosing the distribution of Highlight and Shadow detail, I would say:

How much information you want in any of the zones from darkest to brightest depends on the look or mood you’re going for. You control the ratio of silhouette to background (subject to BG contrast ratio). Variations of that ratio will give a different feeling/tell a different story, just as a key to fill ratio would.

A 3 or 4 stop over-middle grey bright area is going to produce a very different feeling than the same area being only a stop over. 

To the second part: If the information in the shadows is necessary to tell the story, then you want to keep that in there. If it’s not relevant and if it’s not going to otherwise distract by omission then, let it go…. into the darkness.

[silvan schnelli]

@Steven West Thank you for the reply. Ya I suppose it really does depend on the scene and the information I want retain. I guess it is quite straightforward in away and that I probably just need more experience with filming silhouettes to figure our what exposure, and how many stops over or under works best for what types of scenarios and desired atmospheres.

[David Mullen ASC]

All a silhouette means is a dark cut-out foreground subject framed against a lighter background. You have many variations to play with. There is no "silhouette police".

However, I do find myself clarifying with directors what they mean by "silhouette" because sometimes they mean a backlit subject with minimal fill, which is not really a true silhouette.

I've suggested we silhouette an actor but after I'm done lighting and show the director, they often say "the actor looks dark, can we put some light on them?"

[silvan schnelli]

@David Mullen ASC Ah yeah definitely. I feel like I’ve heard those type of stories all too often, but I can see ehy the terminology could lead to those conundrums.