Red One Rental Specs
Any DP would understand the concept -- negative film works the same way, it likes density (exposure).
But while always going for the most exposure would reduce noise, that's not necessarily the defining principle behind how you expose a scene creatively.
For one thing, some DP's prefer the look of a "thinner" negative or in this case, a slightly noisier digital image -- maybe it's part of their creative concept for the film.
Secondly, shots are not out of context, they are part of a sequence that is cut together. So a DP picks a sensitivity rating in general that they prefer for the look they want in terms of noise, black levels, etc. and then they expose the shot within that base. So if the base look is 320 ASA, for example, and within that sequence, you have a camera angle that is two-stops underexposed, maybe because someone switches off some lights in the scene, then two-stops underexposed is the correct exposure for the scene, it really isn't "underexposed" because the image is not going to be lightened in post, it's going to be at the same levels as the other footage, at the same noise level and same black levels, etc.
As always, David Mullen, ASC is a fountain of great knowledge and this post he made was especially helpful to me in understanding and putting into words what "proper exposure" means.
"Noise would only be a problem if either (1) the base rating chosen was noisy in general and having a lot of black in the frame now made that more visible, or (2) a decision was made in post to brighten the dark shot.
Otherwise, don't think of a darker exposure as necessarily being the "wrong" exposure, or that every shot has to be exposed at maximum value to minimize noise -- this would basically be the same as re-rating the sensitivity shot-to-shot and thus having mismatching in base noise levels.
Think of it this way -- if in the scene, all the lights were turned off and the room went pitch black, then the signal on your waveform would hit "zero", right? Is that the "wrong" exposure? Would you change the exposure so that the pitch-black room was still registering a normal level of signal? No, a low level, or no level, is now the "correct" level.
Shots are cut into a sequence and what matters more is that the exposure technique is consistent within a sequence so you aren't radically changing levels once you get into post color-correction.
All that said, when it comes to really dark scenes, it's generally better to be conservative and only underexpose partways, figuring you can always darken it further in post.
That's not the same thing though as saying that you should just expose every shot normally no matter what the mood or look you are going for and do all of the correction in post. If you have a clear creative concept for the look of the scene, then expose for it.
Now if you think your DP is making choices based on a monitor image that is too light, then adjust the monitor or the output of the camera so the recording is biased towards more exposure in general.
In film, it works the same way -- black level is a function of printer light values. In other words, you could shoot with the lens cap on, or send the unexposed negative to be processed normally and printed. Now how black the blacks look will just depend on the printer light level used. Printed in the teens, it looks grainy and milky. Printed in the 40's, it looks very dense and fine-grained.
It is similar with digital -- how clean and black the shadows look is dependent on the final level you choose to set for the color-corrected scene. So maybe a shot that is five-stops under is set to the same levels as a normally exposed scene -- it will end up looking very dark, but it would have the same blacks levels and noise as the normally exposed shot would because you haven't really done anything to "lift" the low signal. So if that's the look you wanted, then the dark shot wasn't really exposed incorrectly.
The danger is that if someone changed their mind in post and now wanted to lift the dark shot. Then you're going to get noise problems. Hence why you want to be a little conservative and give yourself some wiggle room.
Now the other danger though is in dailies and editing, they are working with a shot that is brighter than the look you intended, they will get used to that look and not let you darken it later in post color-correction. So you need a way to make sure that what is used in editing has the correct look.
I definitely agree with how he has put this and always try to expose to the right to get rid of as much noise as I can. If I darken it later then fine but to raise it up can do much more damage.
But while always going for the most exposure would reduce noise, that's not necessarily the defining principle behind how you expose a scene creatively.
For one thing, some DP's prefer the look of a "thinner" negative or in this case, a slightly noisier digital image -- maybe it's part of their creative concept for the film.
Secondly, shots are not out of context, they are part of a sequence that is cut together. So a DP picks a sensitivity rating in general that they prefer for the look they want in terms of noise, black levels, etc. and then they expose the shot within that base. So if the base look is 320 ASA, for example, and within that sequence, you have a camera angle that is two-stops underexposed, maybe because someone switches off some lights in the scene, then two-stops underexposed is the correct exposure for the scene, it really isn't "underexposed" because the image is not going to be lightened in post, it's going to be at the same levels as the other footage, at the same noise level and same black levels, etc.
As always, David Mullen, ASC is a fountain of great knowledge and this post he made was especially helpful to me in understanding and putting into words what "proper exposure" means.
"Noise would only be a problem if either (1) the base rating chosen was noisy in general and having a lot of black in the frame now made that more visible, or (2) a decision was made in post to brighten the dark shot.
Otherwise, don't think of a darker exposure as necessarily being the "wrong" exposure, or that every shot has to be exposed at maximum value to minimize noise -- this would basically be the same as re-rating the sensitivity shot-to-shot and thus having mismatching in base noise levels.
Think of it this way -- if in the scene, all the lights were turned off and the room went pitch black, then the signal on your waveform would hit "zero", right? Is that the "wrong" exposure? Would you change the exposure so that the pitch-black room was still registering a normal level of signal? No, a low level, or no level, is now the "correct" level.
Shots are cut into a sequence and what matters more is that the exposure technique is consistent within a sequence so you aren't radically changing levels once you get into post color-correction.
All that said, when it comes to really dark scenes, it's generally better to be conservative and only underexpose partways, figuring you can always darken it further in post.
That's not the same thing though as saying that you should just expose every shot normally no matter what the mood or look you are going for and do all of the correction in post. If you have a clear creative concept for the look of the scene, then expose for it.
Now if you think your DP is making choices based on a monitor image that is too light, then adjust the monitor or the output of the camera so the recording is biased towards more exposure in general.
In film, it works the same way -- black level is a function of printer light values. In other words, you could shoot with the lens cap on, or send the unexposed negative to be processed normally and printed. Now how black the blacks look will just depend on the printer light level used. Printed in the teens, it looks grainy and milky. Printed in the 40's, it looks very dense and fine-grained.
It is similar with digital -- how clean and black the shadows look is dependent on the final level you choose to set for the color-corrected scene. So maybe a shot that is five-stops under is set to the same levels as a normally exposed scene -- it will end up looking very dark, but it would have the same blacks levels and noise as the normally exposed shot would because you haven't really done anything to "lift" the low signal. So if that's the look you wanted, then the dark shot wasn't really exposed incorrectly.
The danger is that if someone changed their mind in post and now wanted to lift the dark shot. Then you're going to get noise problems. Hence why you want to be a little conservative and give yourself some wiggle room.
Now the other danger though is in dailies and editing, they are working with a shot that is brighter than the look you intended, they will get used to that look and not let you darken it later in post color-correction. So you need a way to make sure that what is used in editing has the correct look.
I definitely agree with how he has put this and always try to expose to the right to get rid of as much noise as I can. If I darken it later then fine but to raise it up can do much more damage.
