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Getting Less Grain


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#1 Simon Walsh

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Posted 12 June 2006 - 05:49 AM

Hi all,

I read somewhere that if you slightly overexpose by 1/2 to 2/3 a stop then you'll get less grain in the image and richer colours. I understand the richness but I always thought that if anything the grain would become even more dense. I'm confused.

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#2 Jamie Metzger

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Posted 12 June 2006 - 07:22 AM

Hi all,

I read somewhere that if you slightly overexpose by 1/2 to 2/3 a stop then you'll get less grain in the image and richer colours. I understand the richness but I always thought that if anything the grain would become even more dense. I'm confused.

Simon Walsh
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Grain is caused when you underexpose, or have blacks with no information in them. I was told personally by William Fraker ASC that even if you want pure blacks/ noir style, you must put atleast 2-3/4 footcandles where you need that black, just so you lessen the grain. You need some information to put black there.

Over exposing is an art in itself. what you mentioned is good, sometimes a 1/3 is best. I've gone 2 over before because it suited the scene. Use exposure wisely, and as a tool.

try shooting a film test. under and over expose, and see where grain is most apparent.
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#3 Sam Wells

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Posted 12 June 2006 - 09:00 AM

Grain is caused when you underexpose, or have blacks with no information in them. I was told personally by William Fraker ASC that even if you want pure blacks/ noir style, you must put atleast 2-3/4 footcandles where you need that black, just so you lessen the grain. You need some information to put black there.


This was one of the more pervasive myths of the seventies.

Try putting "2-3/4 footcandles" in a black night sky :D

There is no 'pure black' short of an opaque d-max on the print (Vision Premire comes pretty close..)

Keep something bright in the frame, keep your printer lights on the high side, and you can "represent" "black".

A slightly denser negative can print down and it's nicer but there's no magic that eliminates graininess; shoot a finer grained stock, shoot 35 instead of S16, etc.

-Sam
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#4 David Mullen ASC

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Posted 12 June 2006 - 11:29 AM

As far as getting better blacks, the notion that you need to put more light on something black to make it blacker is not something I agree with. Obviously the blackest thing of all should be to just shoot with the lens cap on.

There are two different issues. One is the perception of black, with the old rule that something looks blacker when next to something brighter. So in a night scene, a hot spot like a streetlamp will help make the surrounding blacks look blacker by comparison, as opposed to a frame with no highlights. I think this phenomenon is the start of the misconception that you need to pump more light on a black surface -- what you're really trying to do is create a highlight in the blacks.

The other issue is negative density. The black areas in the frame shouldn't have any density on the negative, but how black that looks in the PRINT depends on the exposure (printing lights) that the print gets. If you shoot a piece of negative with the lens cap on and then develop it, how black the print looks will depend simply on the inherent D-max of the print plus the printer lights you use. So if you want deeper blacks in the print, make sure that your highlights look correct printed at a higher set of printer light numbers (i.e. printing "down".) This usually means overexposing the highlights slightly. When those are printed down, the blacks will get denser in the print, up to the D-max point (maximum density.) Some print stocks have a higher D-max like Vision Premier.

So Fraker's techniques worked but the reasoning behind it is a bit flawed (I'm sorry to say). But who am I to argue with a great DP like him. He was right in movies like "Bullit" and "Wargames" to realize that a highlight in the black would make the blacks look richer by comparison. And he's right that a denser negative printed down leads to better blacks.

But adding density in the dark areas does not de facto make them blacker because negative density = information, i.e. detail, something other than pure black. For example, flashing or fogging creates density at the bottom of the characteristic curve, the low-end, but they do not increase the black levels - in fact, they do the opposite, they make black grayer.

Another factor is that if you can't get an overall dense negative that will print at high printer lights, because the film stocks aren't fast enough, the light level is too low, I think another reason for Fraker's way of shooting in the 1970's was that assuming you couldn't print down for deeper blacks, the worst thing would be to have milky detailess blacks, so at least by putting light into the shadows, you are creating shadow detail there rather than have no detail with a veil of gray over that.
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#5 John Pytlak RIP

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Posted 12 June 2006 - 03:18 PM

Generally, overexposure of a color negative film results in "richer" (denser) blacks, with more shadow detail. If you don't want to see any shadow detail in the black area, don't put any light there. Underexposing a color negative film reduces the density of the black areas in the final print, and reduces shadow detail.

A stop or so of overexposure will reduce graininess, as more of the scene information is now placed on the finer-grained mid- and slow-emulsion components of the film, rather than the coarser grained fast components.
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#6 Ignacio Aguilar

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Posted 12 June 2006 - 04:00 PM

Another factor is that if you can't get an overall dense negative that will print at high printer lights, because the film stocks aren't fast enough, the light level is too low, I think another reason for Fraker's way of shooting in the 1970's was that assuming you couldn't print down for deeper blacks, the worst thing would be to have milky detailess blacks, so at least by putting light into the shadows, you are creating shadow detail there rather than have no detail with a veil of gray over that.


Yes, if I recall correctly Fraker first talked about using three or four footcandles on the black areas of the image in an interview about "Looking for Mr. Goodbar" (Richard Brooks, 1977), which he shot using very low light levels on Kodak 5247 (100 ASA). Those days Fraker was also very fond of using filter packs for his films (combining Mitchell A & B Diffusion, Coral, Low-cons or/and Fog Filters) as he was aiming for a softer & diffused look (which IMHO didn't help getting deep blacks).
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#7 Sam Wells

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Posted 13 June 2006 - 08:59 AM

A black surface with some specularity - say a black car at night - rainy streets - etc can often yield what looks like a richer black...

-Sam
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#8 Bob Hayes

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Posted 13 June 2006 - 10:23 AM

I asked Fraker about how he shot the screens on ?War Games?. He said it was impossible to get the blacks in the screens looking black enough because of the projection technique. After tests he found that by putting thin brightly lit frames around the screens the black appeared blacker. This did not change the printing lights. It is just an optical illusion but a very effective one.
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#9 David Mullen ASC

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Posted 13 June 2006 - 12:15 PM

That just goes back to what we are all saying that a bright highlight makes blacks look blacker in comparison.

Plus a wet road increases contrast and takes the dull gray sheen away on the asphalt and makes it very black with bright highlights from reflections.
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#10 Leo Anthony Vale

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Posted 13 June 2006 - 12:58 PM

A black surface with some specularity - say a black car at night - rainy streets - etc can often yield what looks like a richer black...

-Sam


---I used to shoot a lot of a of a 3M(ferrania) 640T slide film. It had a weak cyanish Dmax.

If there was no white highlight in the picture, blacks seemed to disappear.
Yes, specular highlights are quite important, it's like adding salt to chocalate to cut the bitterness, thus making the chocalate sweeter.

---LV

PS 3M also had a 1000T which took a one stop push rather well. and had a decent black.
But sometimes one needs a tungsten film for low light slides.
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#11 fstop

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Posted 13 June 2006 - 01:06 PM

I'm 100% with David on this one. High contrast can create the illusion of deeper blacks, not make the darks deeper.

You have to take Fraker's rule with a giant pinch of salt, much like Storaro's colour coding "rule". It's all just a taste thing, not some gospel technical.

Click here to seea clip from the movie:
http://www.youtube.c...search=wargames

Wargames was dogged with behind the scenes political problems that supposedly emergered because of that computer set (the world's biggest set at the time). Martin Brest was the original director, Geoffrey Kirkland the original designer. The whole thing was a massive collaboration, not taking away from Fraker's undeniable talent (ROSEMARY'S BABY and PROTOCOL are my fave Fraker movies for movement and lighting).
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