Jump to content


Photo

How can I reduce grain in blacks during campfire scene?


  • Please log in to reply
16 replies to this topic

#1 Alex Gaynor

Alex Gaynor

    New

  • Basic Members
  • Pip
  • 8 posts
  • Gaffer

Posted 02 July 2009 - 06:17 PM

Hey guys,

I'm looking for a few opinions on shooting a night campfire scene. I am trying to reduce the amount of "distracting" grain in the blacks at night around a lone man at a campfire. We are shooting Super16mm vision2 stocks, potentially 200t or maybe even 250D. We have filmed a portion of the film already and we are quite happy with the reduced grain in the daylight 50D and 250D stuff so far. The director would like a pretty natural looking campfire scene (ala "Gerry") with no backlight, very little ambient, and sharp falloff. Currently we'll be using a small collection of tungsten heads ranging from 150s to a 1k zip. We have the usual magic gadgets and a small 5500 gennie.

So I guess I'll start by asking if anyone thinks a simple 2/3 overexposure would help and then crushing the blacks in post? Or should I think about pulling the film a stop or two to reduce grain in developing? I've watched various shorts and feature films clips and noticed that some campfire scenes have nice rich blacks with little to no grain, while others have the distracting chunky grain in the blacks while the faces of the actors are still at or just under key.

Thanks for your thoughts.

-alex g.
  • 0

#2 Tom Jensen

Tom Jensen
  • Basic Members
  • PipPipPipPip
  • 1234 posts
  • Camera Operator
  • Dallas, TX

Posted 02 July 2009 - 07:01 PM

You have to light black. Just make sure the exposure of the black falls on the toe of the characteristic curve. I forget where that is though. 4 to 4 1/2 stops under? 5?

Edited by Tom Jensen, 02 July 2009 - 07:02 PM.

  • 0

#3 Tom Jensen

Tom Jensen
  • Basic Members
  • PipPipPipPip
  • 1234 posts
  • Camera Operator
  • Dallas, TX

Posted 02 July 2009 - 09:14 PM

You have to light black. Just make sure the exposure of the black falls on the toe of the characteristic curve. I forget where that is though. 4 to 4 1/2 stops under? 5?


Don't forget the moon as a motivating source. You need to break up the black areas with some light.
  • 0

#4 Alex Gaynor

Alex Gaynor

    New

  • Basic Members
  • Pip
  • 8 posts
  • Gaffer

Posted 03 July 2009 - 02:12 PM

Don't forget the moon as a motivating source. You need to break up the black areas with some light.


Good ideas, thanks for the input Tom!
  • 0

#5 David Mullen ASC

David Mullen ASC
  • Sustaining Members
  • 19760 posts
  • Cinematographer
  • Los Angeles

Posted 03 July 2009 - 03:57 PM

I know that "you have to light the blacks to make them black" is a thing that some DP's have said, but it's a bit of an old wives' tale. You can't get blacker than no exposure at all.

Black is determined to some extent by the printer lights or in digital, where you set the black level. For example, take an unexposed piece of color negative film (essentially "black"), develop it normally, and then print it in the 20's, 30's, 40's, etc. What you'll see is that the blacks in the print get blacker as the printer lights get higher. So if you want deep blacks in a print, it needs to be printing at higher numbers, and in order to do that, your subject in the frame has to be exposed so that it prints at high numbers, i.e. the overall negative is denser than normal. But that doesn't mean you have to add light to the shadows because then you're just reducing contrast.

In digital, it's similar -- black is whatever you decide it is -- you can take washed out footage and bring it down until the blacks are at "0". But you may not like the way that looks, which is why it's better to get good blacks in the original and a well-exposed image so that you can bring it down slightly without it looking crushed and contrasty.

Now there is a separate issue, which is the illusion of good blacks, or perception. The trick there is to put something bright in the blackness, like a spot of light, because the surrounding area will look blacker in comparison. With no highlight reference in the frame, then you are more likely to think the blacks are lighter.

With digital color-correction, you do have the option of playing with the contrast, gamma -- in this case, you will get deeper blacks with less noise if you can crush the shadow detail down a little but leave the highlights alone. Now this is a case where a little extra fill light may be necessary to compensate so that the final contrast looks the way you want.

In other words, you can set the blacks where you want them either by printing at high numbers or by setting the blacks that way in digital color-correction... but doing this will affect the shadow detail and the highlight exposure, so in order for those to look right, you may need more overall exposure (i.e. rating the stock slower) and you may need a little extra fill IF you want deep blacks but some shadow detail. If you just want black shadows, then leave them unlit and just make sure your highlights have enough exposure to bring the shot down overall.

In terms of grain, just remember that fast films have larger grains, that's why the film is faster, so you can't really get rid of those bigger grains.
  • 0

#6 Tom Jensen

Tom Jensen
  • Basic Members
  • PipPipPipPip
  • 1234 posts
  • Camera Operator
  • Dallas, TX

Posted 03 July 2009 - 04:55 PM

I know that "you have to light the blacks to make them black" is a thing that some DP's have said, but it's a bit of an old wives' tale. You can't get blacker than no exposure at all.

Black is determined to some extent by the printer lights or in digital, where you set the black level. For example, take an unexposed piece of color negative film (essentially "black"), develop it normally, and then print it in the 20's, 30's, 40's, etc. What you'll see is that the blacks in the print get blacker as the printer lights get higher. So if you want deep blacks in a print, it needs to be printing at higher numbers, and in order to do that, your subject in the frame has to be exposed so that it prints at high numbers, i.e. the overall negative is denser than normal. But that doesn't mean you have to add light to the shadows because then you're just reducing contrast.


But, when you have literally no exposure on the negative you only have base + fog. To me just getting some exposure looks better than no exposure. There will be lots of times when you have no exposure and that's why I mentioned using the moon as a motivating source. It gives you a reason to light something in the background that lessens the perception of grain and breaks up the black mass as David mentioned. Isn't an unexposed negative essentially "white" though. ie; the more exposure you give it, the darker the negative? Maybe I just misunderstood what you said.
  • 0

#7 David Mullen ASC

David Mullen ASC
  • Sustaining Members
  • 19760 posts
  • Cinematographer
  • Los Angeles

Posted 03 July 2009 - 07:47 PM

But, when you have literally no exposure on the negative you only have base + fog. To me just getting some exposure looks better than no exposure. There will be lots of times when you have no exposure and that's why I mentioned using the moon as a motivating source. It gives you a reason to light something in the background that lessens the perception of grain and breaks up the black mass as David mentioned. Isn't an unexposed negative essentially "white" though. ie; the more exposure you give it, the darker the negative? Maybe I just misunderstood what you said.


If you expose something in that area above the base fog, in the toe, it's detail, it's not black. Black is black, the absence of any exposure. Underexposed detail is not black.

Base fog is base fog - exposing more detail in it doesn't make it less foggy.

The question is how to get a solid black, and the answer is that the image has to be printed "down".

The more you expose a negative the denser it gets, but we're talking about blacks in the positive image, not blacks on the negative, which are the white areas in the image.

I mean, what if you wanted a face against a solid black background, like the interviews in "Reds"? Lighting the background isn't going to make it blacker. Lighting the blacks up until they become dark grey doesn't make them blacker, it makes them dark grey. What makes the background blacker is printing the image down, which means that the highlights have to be denser than normal so that they can be printed at higher printing light numbers to become normal in brightness. Then the blacks will be as black as the D-max of the print stock allows.

I'm just saying that you're mixing metaphors, so to speak. Yes, having detail in the shadows may distract the eye from foggier blacks, or it may allow you to print down the image and get good blacks plus keep desired shadow detail. Same goes for putting a bright spot in the darkness -- it makes the blacks feel blacker in comparison.

But if you want a solid, pure, featureless black, it's all about how you print the image or where you set the blacks in digital color-correction -- it has nothing to do with exposing information in the blacks.

You can't get blacker than the base fog level. Any exposure you add to that just adds density. Base fog is density -- a really pure black would mean a completely clear area on the negative. But you can't get that because there is always some base fog density, so instead of completely clear, you have a slight fog of density. So how can adding more density (i.e. exposure, detail) to the toe create deeper blacks? If the blackest black is the bottom -- the base fog level -- and then any level above that is less than black. So adding information to the negative at the bottom end is adding detail to the blacks.

This is where the old wives tale part comes in, when a DP says that you have to pound a black object with enough light to cause some silver to form during processing. It's completely not true. The purest black would be an impossible clear negative with no silver at all, then above that would be the base fog density, and then above that would be tiny amounts of silver created by exposure - which is detail. The more silver that forms, the more detail in the image until you reach pure white in the image, which is pure black on the negative.

Black is the absence of information.

Again, re-read my post. Take an unexposed image - basically as if you shot with the lens cap on -- and develop it, and then print it at different printer lights and project the print. The black looks foggy at low printer lights and dense at high printer lights. So the goal is to expose the subject in a way that allows you to print at high printer lights, which would then make any blacks in the frame look blacker.
  • 0

#8 Tom Jensen

Tom Jensen
  • Basic Members
  • PipPipPipPip
  • 1234 posts
  • Camera Operator
  • Dallas, TX

Posted 03 July 2009 - 08:04 PM

You make several excellent points. It's been a while since I shot any film. Let me ask this. Does exposure in the toe reduce the grain as opposed to a negative with base +fog only. As I think about it I'm confusing printing black and lifting an underexposed negative which will of course give you more grain. If you print an underexposed negative dark, it will be black.
  • 0

#9 David Mullen ASC

David Mullen ASC
  • Sustaining Members
  • 19760 posts
  • Cinematographer
  • Los Angeles

Posted 03 July 2009 - 08:37 PM

You make several excellent points. It's been a while since I shot any film. Let me ask this. Does exposure in the toe reduce the grain as opposed to a negative with base +fog only. As I think about it I'm confusing printing black and lifting an underexposed negative which will of course give you more grain. If you print an underexposed negative dark, it will be black.



Again, it's a bit of a mixed metaphor when we say that exposing more gives us less grain. The grain size is designed into the stock and determines its speed -- faster films have larger grains because that's what makes them faster, a larger grain has more surface area exposed to the light. What more exposure does is expose the slower, smaller grains inbetween the larger, faster grains, thereby filling-in the gaps and making the structure tighter. And if it is tighter, we have a harder time seeing the size of the bigger grains. If we underexposed, then only the larger faster grains would get developed, the smaller ones washed away, and we'd see these big grains swirling around more clearly.

As you say, if you print an underexposed negative darker, the blacks will be blacker -- because its the amount of light used in printing that matters. But of course, we tend to print underexposed negatives lighter and thus get milkier blacks and see more grain.

An underexposed area of the frame, by definition, is "thin" on the negative -- the image was darker in those areas so they exposed fewer grains. Printing down will help hide some of that graininess, and certainly printing up will make it worse, but this doesn't mean you can't have dark areas in the frame (otherwise the photography would be flat) but it does mean that your overall density, or the density of whatever is determining the printing -- usually the subject -- has to allow printing at higher printing lights so that the shadow areas will look nice and rich. This is why we tend to rate stocks slower than recommended.

But to truly have smaller grains in the image, you have to use slower-speed stock.
  • 0

#10 Tom Jensen

Tom Jensen
  • Basic Members
  • PipPipPipPip
  • 1234 posts
  • Camera Operator
  • Dallas, TX

Posted 03 July 2009 - 08:58 PM

OK Thanks, that makes perfect sense, now. I can be a little "dense" myself at times.
  • 0

#11 Alex Gaynor

Alex Gaynor

    New

  • Basic Members
  • Pip
  • 8 posts
  • Gaffer

Posted 06 July 2009 - 11:03 PM

But to truly have smaller grains in the image, you have to use slower-speed stock.
[/quote]

Thanks David and Tom for the discussion and all the info. Do you have any thoughts on pulling a stop in processing to help diminish grain in the super16mm negative? The side effect being this would also lower contrast which we would hope to add back in the DI process by bringing down the shadows and midtones...
  • 0

#12 David Mullen ASC

David Mullen ASC
  • Sustaining Members
  • 19760 posts
  • Cinematographer
  • Los Angeles

Posted 06 July 2009 - 11:36 PM

But to truly have smaller grains in the image, you have to use slower-speed stock.


Thanks David and Tom for the discussion and all the info. Do you have any thoughts on pulling a stop in processing to help diminish grain in the super16mm negative? The side effect being this would also lower contrast which we would hope to add back in the DI process by bringing down the shadows and midtones...


It's not the pulling that reduces the grain so much as the overexposure you do to compensate for the pull. And again, you aren't really reducing the size of the grains, you are just exposing for the smaller ones between the big ones.

Which again comes down to whether it's better to use, for example, 200T overexposed and pulled one stop versus 100T rated normally, in terms of grain.

I don't think it gains you much to get fancy or tricky, not if you are doing a D.I. Not to mention, some labs don't offer pull processing for 16mm. I would use the slowest speed stock that is practical and expose it well, and process it normally.
  • 0

#13 Alex Gaynor

Alex Gaynor

    New

  • Basic Members
  • Pip
  • 8 posts
  • Gaffer

Posted 07 July 2009 - 02:23 AM

I don't think it gains you much to get fancy or tricky, not if you are doing a D.I. Not to mention, some labs don't offer pull processing for 16mm. I would use the slowest speed stock that is practical and expose it well, and process it normally.
[/quote]

Thanks David, that's the words of wisdom I was looking for. We're shooting tomorrow night, I'll try to post some stills when we get our dailies back. Thanks for the advice.
  • 0

#14 Hampus Bystrom

Hampus Bystrom
  • Basic Members
  • PipPipPip
  • 132 posts
  • Student
  • Stocktown

Posted 07 July 2009 - 05:56 AM

We're shooting tomorrow night, I'll try to post some stills when we get our dailies back. Thanks for the advice.


Please do! I have some campfire scenes that I would like to execute as non-grainy as possible. I love this scene from Van Sant's Last Days:

Posted Image
  • 0

#15 Tom Jensen

Tom Jensen
  • Basic Members
  • PipPipPipPip
  • 1234 posts
  • Camera Operator
  • Dallas, TX

Posted 07 July 2009 - 07:00 AM

There are some good campfire scenes in Dances with Wolves.
  • 0

#16 Alex Gaynor

Alex Gaynor

    New

  • Basic Members
  • Pip
  • 8 posts
  • Gaffer

Posted 11 August 2009 - 11:43 PM

For anyone interested, here's a screengrab I was able to steal from our dailies. Hopefully I can post a quicktime eventually for the grain movement part of this discussion. I just thought I would post a pic for any newcomers that might be able to learn from my experience. I ended up shooting on Vision 3 250D 7207. I was nervous at first about using the 250D, but the 200T wasn't quite fast enough (I only had access to 40 amps), and I'm never quite happy with how 500T looks in Super16. So after doing a few stills tests and reading some old articles on how "Backdraft" used daylight stocks to get that nice orange fire look, we went for it. For the daylight portion of our film, I've been using the antique suede quite a bit, so the warm fire was exactly what the director and I were looking for. I shot the colorchart under a clean tungsten light and did the usual flicker generator with a redhead and 300w gelled with a mix of CTS, Amber, and red pushing through a 4x4 of hampshire from about 6 feet away. I used a 650 to throw a little light towards the background (nearby grass and shrubs- spot reading was 4 stops under) for a little depth, and rounded off our amps with a 150w with 250 about 20 feet away. My incident meter read the 150w at about 6 stops under, but it was just enough to provide a slight sheen on the guy's hair and separate him from true black behind him. I shot the scene on an Aaton XTR w/ canon zoom, no filters, at a f2.8. His key ranged from a 1/3 stop over to 1 stop under. Again I'll try to post a quicktime eventually to show the flicker and grain size. Overall, I'm pleased with the look, and the blacks came out rather clean and dark. Thanks again for everyone's suggestions and time.

Attached Images

  • scorch_fire2.jpg

  • 0

#17 Gregory Middleton

Gregory Middleton
  • Basic Members
  • PipPip
  • 78 posts
  • Cinematographer
  • Vancouver BC

Posted 12 August 2009 - 02:13 AM

That looks very nice Alex well done.
I just read all of those posts and thought I would add one thing. One thing that can contribute to more grain or noise in the blacks is not just the Level of exposure and the subsequent light you print at (40's deep blacks ' 20's more milky) but also the balance of those lights.
Film stocks will show more noise or grain if you color time them aggressively away from their normal balance. If ,for example, you had not warmed your fire light up at all (by dimming, gel or using Daylight film as you did) and used the balance of the printer lights to create the tone you wanted you would notice more noise and grain that you have now.
You can see other examples of this effect in underexposed daylight scenes when they have run out of light and pulled their 85 filter etc trying to get the last few moments on film. Most of what you see is due to underexposure but some of what you see is the grain picking up color from the aggressive timing lights to get the shot back in balance. Often at that time of day the light is 10000k. Thats a long way to bring back to 3200k. The Blacks start to pick up all kinds of color.

cheers



For anyone interested, here's a screengrab I was able to steal from our dailies. Hopefully I can post a quicktime eventually for the grain movement part of this discussion. I just thought I would post a pic for any newcomers that might be able to learn from my experience. I ended up shooting on Vision 3 250D 7207. I was nervous at first about using the 250D, but the 200T wasn't quite fast enough (I only had access to 40 amps), and I'm never quite happy with how 500T looks in Super16. So after doing a few stills tests and reading some old articles on how "Backdraft" used daylight stocks to get that nice orange fire look, we went for it. For the daylight portion of our film, I've been using the antique suede quite a bit, so the warm fire was exactly what the director and I were looking for. I shot the colorchart under a clean tungsten light and did the usual flicker generator with a redhead and 300w gelled with a mix of CTS, Amber, and red pushing through a 4x4 of hampshire from about 6 feet away. I used a 650 to throw a little light towards the background (nearby grass and shrubs- spot reading was 4 stops under) for a little depth, and rounded off our amps with a 150w with 250 about 20 feet away. My incident meter read the 150w at about 6 stops under, but it was just enough to provide a slight sheen on the guy's hair and separate him from true black behind him. I shot the scene on an Aaton XTR w/ canon zoom, no filters, at a f2.8. His key ranged from a 1/3 stop over to 1 stop under. Again I'll try to post a quicktime eventually to show the flicker and grain size. Overall, I'm pleased with the look, and the blacks came out rather clean and dark. Thanks again for everyone's suggestions and time.


  • 0


Broadcast Solutions Inc

Wooden Camera

Visual Products

Ritter Battery

Gamma Ray Digital Inc

Paralinx LLC

CineTape

rebotnix Technologies

Glidecam

Willys Widgets

The Slider

Aerial Filmworks

Abel Cine

Media Blackout - Custom Cables and AKS

Rig Wheels Passport

Opal

Technodolly

CineLab

Tai Audio

Metropolis Post

FJS International, LLC

Metropolis Post

Ritter Battery

Glidecam

Technodolly

FJS International, LLC

CineLab

CineTape

Gamma Ray Digital Inc

Abel Cine

Willys Widgets

The Slider

Broadcast Solutions Inc

Opal

Paralinx LLC

Aerial Filmworks

Rig Wheels Passport

Media Blackout - Custom Cables and AKS

Tai Audio

rebotnix Technologies

Wooden Camera

Visual Products