under exposure

[Ravi Walia]

Hi I am doing a film for theatre release and ofcourse i do not have DI option available.I have read many times you guys talking about slightly over exposing the negitive to get all the info and also deal with grain problem.but pl tell me how do you guys deal with the situation where you have to show dark under lit location.Do you guys really underexpose it by 2-3 stops if require or expose healthy negitive and then print it under. thanks

[Stephen Williams]

Hi I am doing a film for theatre release and ofcourse i do not have DI option available.I have read many times you guys talking about slightly over exposing the negitive to get all the info and also deal with grain problem.but pl tell me how do you guys deal with the situation where you have to show dark under lit location.Do you guys really underexpose it by 2-3 stops if require or expose healthy negitive and then print it under. thanks

 

Hi,

 

For a Night scene I would underexpose by 3 stops, if I was not going to supervise the post production. Then its fairly clear to the night grader that people running around with tourches are indeed in the dark! For a DI, I would go at least 2 Stops under. (That in effect is overexposing!)

 

Stephen

[Stuart Brereton]

Do you mean having very underexposed areas in the frame, or generally underexposing the neg?

 

Your dark, underlit location could have small lit areas which are at key level, surrounded by huge areas of shadow, or it could be lit with less contrast and underexposed by 3 stops.

 

The important thing is to get your key lights at the level you want them, be it on stop, or 3 stops under. If you heavily underexpose your key lights, and then decide later that you overdid it and print up, you'll start to see grain in the shadows.

 

I'd shoot some tests of faces etc with varying degrees of underexposure. Pick the one you like,then when you light the location set your keylights to that level and let the shadows fall away into black.

[David Mullen ASC]

It'a all about printer lights. You may decide that you prefer the look of a print using lights that are in the low 30's instead of the mid 20's, because then the blacks, grain, contrast, and saturation are of a certain quality. So in a "normal" scene where the faces are at key exposure, it may mean rating the stocks 2/3's of a stop overexposed than normal to get those printer lights.

 

Now still printing at those lights, you may expose a scene to look darker than that, so a dusk exterior shot may be two stops under "key" but you are still using the slower ASA rating and still printing at those higher numbers.

 

The danger with too much underexposure is that you may decide the shot now looks too dark and thus require printing at lower numbers to brighten the image.

 

In terms of underexposing night, you can't make generalizations like "everything is underexposed by three stops" -- it's the difference between dim and dark. A dark scene may be mostly black but have small areas at near key exposure, even overexposure. A dim scene has overall underexposure where no highlight reaches key exposure, sort of murkiness.

 

So the goal is to expose to create the look you want, starting from the base ASA rating and printer lights you want to use. So a dim scene may be underexposed by a couple of stops as long as it is is supposed to look that way. Trouble is that mistakes -- too much underexposure, requiring you compensate by printing at lower numbers -- look worse than not enough underexposure, where you have to raise the printer lights even more to darken the image enough. So be conservative -- underexpose for effect, but give yourself some leeway to further darken the image on the print.