Noise and Lighting things "correctly"

[Brian Petersen]

When reading various threads, specifcially about noise and sensitivity with the HVX, I often come across people saying stuff like, "Well, these were run and gun shots, when the scene is lit correctly, it will be beautiful."

It makes sense in fully lit situations. I understand the concept of adding light where it's too dark and taking away light where it's too light to stay within the dynamic range of the camera. But what about low-key lighting? Does "correct" lighting apply there as well? What if I want the shadows to fall into black. Is it correct to leave the shadows out of the range of the senstitivty or should I be adding light to the shadows to bring it just within the dynamic range of the camera and then crush the blacks in post if I want it totally black?

Do I still follow the general rule of adding light to shadows and taking away light from highlights to have everything fit in the dynamic range when dealing with low-key noir style scenes? How does doing that affect noise performace? How would NOT doing that affect noise performace?

In the footage I've seen it seems I see noise in the barely lit portions of the frame, but not really any noise in the sections where there is no light (like the night sky). I just don't understand how "proper" or "correct" lighting will eliminate or diminish noise in noir type shots where the actor's face itself goes from highlight on one side to complete black shadow on the other. How can you control or elimnate noise in a shot like that?

 

[profnoxin]

This really depends on what you want your footage to look like in the end. If you want your footage to drop out to black, I tend to just let it fall away, and then crush it down/adjust my contrast to where I want it in post. I try to shoot as much for my correct contrast ratio, but that is based on your average exposure. If my f-stop is a 5, two down is black, two up is white, I try to keep my highlights at 1 1/2 to 2 over, my key at exposure, and no fill. But this is all selective. When shooting film, there are no worries. I would definately not suggest filling your shadows however. Crushing it in post is going to add more noise elements than just shooting to your meter.

Hope this helps.

 

[Ralph Oshiro]

What I've learned using my DVX100 is to, "overlight everything (while still maintaining detail in your highlights--DON'T OVEREXPOSE), and bring everything down in post." That's a neat trick to lower your noise floor. Also, in high contrast, low key scenes, I've found that for some reason, the noise disappears. In low contrast scenes, however, even when you have as much as 5,000 footcandles of light (typical overcast daylight scene) in your scene, if the contrast is low, you get lots of noise no matter what!