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#1 Demetrius Carroll

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Posted 08 September 2006 - 10:22 PM

Let?s say I want to achieve a deep rich black and I?m lighting for a close up. I want little grain, and considerable fall off. There seem to be two schools of thought. 1. Use a low speed film and the parts of the frame that aren?t even exposed will go absolute black. 2. Use a fast film and achieve a ?true black? by virtue of a diminishing gray scale. My question is: what are the benefits/hindrances of either approach? In my case, I?m at a film school where my largest available light is a 2k, and it doesn?t really seem I can?t really use method 2. So should I use method 1 with let?s say 100T, and only expose for the subject, to get total black in the background? Furthermore, when I look at classic noirs, The Big Combo for example, where I don?t believe they had anything but 200 ASA at the most, should I proceed with the notion that they too were simply not exposing portions of their frame to achieve true black. And if I use method 1 what happens to the edge of the frame between properly exposed and underexposed? Is there a grainy ring around everything? And what if I?m using Super 16? If I can get more precise with this question, please let me know.
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#2 Charles MacDonald

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Posted 08 September 2006 - 10:49 PM

Let?s say I want to achieve a deep rich black ...t. 1. Use a low speed film and the parts of the frame that aren?t even exposed will go absolute black. 2. Use a fast film and achieve a ?true black? by virtue of a diminishing gray scale. My question is: what are the benefits/hindrances of either approach? In my case, I?m at a film school where my largest available light is a 2k, and it doesn?t really seem I can?t really use method 2. So should I use method 1 with let?s say 100T, and only expose for the subject, to get total black in the background?....... if I use method 1 what happens to the edge of the frame between properly exposed and underexposed? Is there a grainy ring around everything? And what if I?m using Super 16? If I can get more precise with this question, please let me know.

Unless you want a "grainy look" is is always safe to use the lowest speed you can..

to get deep blacks you have to have contrast between the subject and the "blackground" :) that also faviours the lower speed films. OTOH you do need to be sure that you have ENOUGH light to get a solid exposure of your forground subject.

I am not sure what you are thinking of when you talks about properly exposed and under exposed, you will get a fade to black in th eareas you don't light, and the negative should look clear, and print black in the under/unexposed areas....
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#3 David Mullen ASC

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Posted 09 September 2006 - 03:02 AM

There is the technical "black" and the perception of black in an image.

For example, blacks will look blacker when there is a bright area in the frame -- if everything is dim, then the blacks in the frame will feel less black, whether or not the black level is actually the same technically as the shot with a bright spot or area surrounded by black.

The contrast of slow and fast film is not very different -- for example, Vision-2 100T to Vision-2 500T will have similar contrast, blacks, and saturation. They only vary by graininess, the slower films being less grainy.

But when you are judging black, the question is are you talking about the blacks in a print made off of the negative or in a video transfer of the film? If you are talking about the print, how dense the blacks will look will depend on the D-Max of the print stock (Vision Premier print stock has the highest, but it's not available in 16mm) and the printer lights used. For example, you could just send unexposed film to the lab, as if you had shot with the lens cap on, develop it, and then make a print at different printer light numbers. You'll see that the higher the printer light numbers, the denser the blacks on the print, up to the D-Max (maximum density) that the stock allows.

So if you want the blacks to be deeper in your image, you should expose or rate the negative in such a way as to need higher printer light numbers to look normal in brightness. For example, if a normally exposed film needs to be printed at 25/25/25 to look correct, then if you had rated the stock one-stop slower than recommended (i.e. overexposed everything by one stop), and then needed to print at, let's say, 33/33/33 to look normal, you'd notice that the blacks in the print were richer, deeper.

So:
(1) use a print stock with a high D-Max
(2) expose the negative enough that it needs higher printer lights, within reason (overexpose too much and you either hit the top of the 1-to-50 scale when correcting, or you start to lose highlight detail)
(3) have something bright in the frame, surrounded by black.

If you are talking about video transfers, then at least exposed well enough that the image does not need to be gain-boosted in the transfer to look normal in brightness, and then set the blacks at the level you want.

If you want less grain, use slower film and expose it well.
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#4 Demetrius Carroll

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Posted 10 September 2006 - 02:02 PM

Thank you guys for your help. I think what I really want some clarification on is if it?s a true statement that DP?s are at times shooting low speed filmstock and willfully unexposing portions of the frame to achieve a deep black. And if they do so, how are they managing to control grain in the area of the frame between properly exposed and totally unexposed since it is my understanding that grain ?lives? in the underexposed areas. Let?s say I have a subject sitting in a chair and get an f2.8 on my subject, an f1.3 on the chair, and E on the background wall and I?m shooting 100T for example.
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#5 David Mullen ASC

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Posted 10 September 2006 - 06:47 PM

Thank you guys for your help. I think what I really want some clarification on is if it’s a true statement that DP’s are at times shooting low speed filmstock and willfully unexposing portions of the frame to achieve a deep black. And if they do so, how are they managing to control grain in the area of the frame between properly exposed and totally unexposed since it is my understanding that grain “lives” in the underexposed areas. Let’s say I have a subject sitting in a chair and get an f2.8 on my subject, an f1.3 on the chair, and E on the background wall and I’m shooting 100T for example.


You're a little confused -- obviously by definition a dark area is underexposed and a true black area shouldn't have any exposure at all in it! Black is what you'd get if you left the lens cap on. But how rich and dense that black looks depends on what printer lights it is printed at (or what video level it is set at.)

But unfortunately, you don't base the printer lights or video levels on the shadows or blacks so much as you do on the overall frame and the key subject, so you want to expose a film negative well enough so that you won't have to lighten the image to make the subject look correct and thus milk out the blacks, plus increase the graininess. You want the subject exposed enough to allow you to darken it (print down) to normal brightness and thus make the blacks blacker by pushing them down rather than lifting them up in the print.

Grain is most visible in the midtones. In a print made off of a negative, a true black should have maximum density and a true white should be clear. So the grain is mostly seen in the midtones. Now if you printed up and thus lifted the blacks into grey milkiness, then grain would also be visible there.

So if you are shooting on 100T film and your subject is at f/2.8, and you expose at f/2.8 based on a 100 ASA rating, then print at a normal set of lights, the blacks & grain should reproduce as the film was designed to.

But let's say that you look at the print and the subject doesn't look bright enough and you print "up" (lower numbers) -- now your blacks will get lifted and the grain will get worse. On the other hand, if the subject looked a little bright so you ended up printing "down" (higher numbers) to normal, then the blacks would get richer and the grain would get tighter.

Hence why many people rate a 100T stock at 80 or 64 ASA overall so as to allow printing at higher printer light numbers and getting snappier blacks, better grain.

Black levels are really a function of printer lights. If your image prints in the mid to high 30's, or low 40's, your blacks should be rich. If you print in the low 20's or teens, your blacks will be milky and grainy. But what determines those printer lights is the density of the negative, so make sure your negative has enough density (exposure.)

Slow-speed film like 5245 50D had a little more contrast than other films, but otherwise, your contrast and black levels for Vision-2 100T up through Vision-2 500T should be the same -- they were designed that way, to match each other. However, one reason people get more contrast when shooting interiors on 100T stock is simply that they can't get the fill level as high to match their key level because of the overall light levels needed, whereas on fast film in low-light, natural room ambience can fill in the shadows. But if you raise your key level from f/2.8 at 500 ASA to f/5.6 at 125 ASA (a four-stop increase in key light level needed) you'd also need to increase the ambient fill level by four stops to maintain the same contrast.
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#6 Dominic Case

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Posted 10 September 2006 - 07:37 PM

think what I really want some clarification on is if it?s a true statement that DP?s are at times shooting low speed filmstock and willfully unexposing portions of the frame to achieve a deep black. And if they do so, how are they managing to control grain in the area of the frame between properly exposed and totally unexposed

If you lght your subject and expose correctly for that, then the background will go as dark as it reall y is in comparison with the subject.

So the more light you have in the foreground, the darker the relatively unlit background will be, by comparison.

And the brighter the foreground, the slower speed stock you can use. Which means finer grain.

Grain tends to show up most in dark grey areas, as more of the large grains and fewer of the smaller ones are exposed in the shadows. But graininess is very largely a perceptual thing, and a well-lit foreground with some good sharp edges will effectively take the eye away from any grain structure that there might be in the darker background.

And also, some good deep blacks in the background not only conceal grain in those areas, they give more shape to the whole image and once again take the eye away from any perception of overall graininess.
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#7 Demetrius Carroll

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Posted 10 September 2006 - 07:38 PM

David, thank you very much! This really helps me out. Furthermore it makes the reasoning behind slightly overexposing the negative crystal clear. I appreciate it.

You're a little confused -- obviously by definition a dark area is underexposed and a true black area shouldn't have any exposure at all in it! Black is what you'd get if you left the lens cap on. But how rich and dense that black looks depends on what printer lights it is printed at (or what video level it is set at.)

But unfortunately, you don't base the printer lights or video levels on the shadows or blacks so much as you do on the overall frame and the key subject, so you want to expose a film negative well enough so that you won't have to lighten the image to make the subject look correct and thus milk out the blacks, plus increase the graininess. You want the subject exposed enough to allow you to darken it (print down) to normal brightness and thus make the blacks blacker by pushing them down rather than lifting them up in the print.

Grain is most visible in the midtones. In a print made off of a negative, a true black should have maximum density and a true white should be clear. So the grain is mostly seen in the midtones. Now if you printed up and thus lifted the blacks into grey milkiness, then grain would also be visible there.

So if you are shooting on 100T film and your subject is at f/2.8, and you expose at f/2.8 based on a 100 ASA rating, then print at a normal set of lights, the blacks & grain should reproduce as the film was designed to.

But let's say that you look at the print and the subject doesn't look bright enough and you print "up" (lower numbers) -- now your blacks will get lifted and the grain will get worse. On the other hand, if the subject looked a little bright so you ended up printing "down" (higher numbers) to normal, then the blacks would get richer and the grain would get tighter.

Hence why many people rate a 100T stock at 80 or 64 ASA overall so as to allow printing at higher printer light numbers and getting snappier blacks, better grain.

Black levels are really a function of printer lights. If your image prints in the mid to high 30's, or low 40's, your blacks should be rich. If you print in the low 20's or teens, your blacks will be milky and grainy. But what determines those printer lights is the density of the negative, so make sure your negative has enough density (exposure.)

Slow-speed film like 5245 50D had a little more contrast than other films, but otherwise, your contrast and black levels for Vision-2 100T up through Vision-2 500T should be the same -- they were designed that way, to match each other. However, one reason people get more contrast when shooting interiors on 100T stock is simply that they can't get the fill level as high to match their key level because of the overall light levels needed, whereas on fast film in low-light, natural room ambience can fill in the shadows. But if you raise your key level from f/2.8 at 500 ASA to f/5.6 at 125 ASA (a four-stop increase in key light level needed) you'd also need to increase the ambient fill level by four stops to maintain the same contrast.


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