Mathew Collins

I don't understand the question. What do you mean by "leave the roll as it is?" Do you mean if in mid-roll and you switch to a new situation and you don't shoot a new grey scale?

David,

No. But I am adding your question as well.

My original question was

If one 'shoots one gray scale at the head of the roll, in "white" frontal lighting' and 'sign with a note explaining the look of the scene if necessary like "COLOR: GOLDEN LATE-AFTERNOON" or "COLOR: BLUE MOONLIGHT", etc.'

Would the colorist not perform any changes in the roll?

The softness is determined by the size of the source relative to distance -- a book light only makes it softer if it helps fill the diffusion frame more evenly from corner to corner but once you do that, the size is what is determining softness.

David,

> The softness is determined by the size of the source relative to distance

Could you explain 'size of the source relative to distance'?

>a book light only makes it softer if it helps fill the diffusion frame more evenly from corner to corner but once you do that,

Would it be possible fill the diffusion frame more evenly from corner to corner, so that a light meter provide the same reading throughout the frame?

A booklight will make a source softer than the same light just through the same diffusion. You're either using a soft bounce like white, which will scatter more before the diff, or a harder bounce, which adds distance between the fixture and diff and thus creates a larger source on the diff, causing the light to be softer. So a booklight would be good for where you don't have space to get the light far enough from the diff to create a large enough source to wrap/be as soft as you want. But the side effect is that light gets everywhere and if you don't have the grip equipment to deal with that it can be a bit of a pain.

 

So Robyn, you're kind of right in that its really the size of the diff frame that matters in terms of softness, but also a booklight can make light softer by using a soft bounce to double diff the light. As actually in the example I posted earlier for this thread, I put a Joker 800 through opal, decided it wasnt soft enough, and added a sheet of 216 or 250 to the fixture in addition to the opal. Similar effect to using a booklight. The opal is still the "source" but the light coming into it is already soft. Unless you're making your booklights with a mirror, you're definitely adding softness before the diff frame.

Will,

Your first experiment-book lighting shows that it is useful when not possible to increase the distance between light-source and diffusion frame.

But in the second experiment you are using 2 layer diffusion in front of the light-source.

Can we compare these 2 experiments? Would it provide the same results?

If they are transferring to tape from the negative, the printer light info is useless to the colorist -- there's no print! Only a print timer could use that info. For just a transfer to video, the lab merely needs to know the negative developing instructions (i.e. "normal" or "push one stop", etc.) on the work order as well as to "prep for telecine."

 

You can shoot one gray scale at the head of the roll, in "white" frontal lighting (white for the color balance of the stock) with no glare on the card, perhaps with a face as well holding the card, and exposed at the rating you are giving the film. After the card, you can shoot a sign with a note explaining the look of the scene if necessary like "COLOR: GOLDEN LATE-AFTERNOON" or "COLOR: BLUE MOONLIGHT", etc. just as an extra explanation.

 

You don't need to reshoot the gray scale until you change the timing, for example, if you change your base ASA rating, change the film stock, change the processing, or change the color balance (for example, in mid roll, you now have a scene under greenish fluorescents. If you shoot the gray scale under greenish flourescent lighting, they would color-correct the green out to make the grey scale look grey.)

>You can shoot one gray scale at the head of the roll, in "white" frontal lighting (white for the color balance of the stock) with no glare on the card, perhaps with a face as well holding the card, and exposed at the rating you are giving the film. After the card, you can shoot a sign with a note explaining the look of the scene if necessary like "COLOR: GOLDEN LATE-AFTERNOON" or "COLOR: BLUE MOONLIGHT", etc. just as an extra explanation.

David,

A small question, In this situation would the colorist leave the roll as it is?

Thank you David, Adrian, Alexandre and John

If you put a grey card next to a paler face and spot-metered the grey card and exposed for that reading, then the paler face would render as being paler.

 

If you spot-metered the pale face instead and exposed for that reading, then the pale face would look darker, as if it were 18% grey in brightness. The spot-meter is assuming what you are pointing it at is 18% grey in terms of the reading you get.

 

So you can spot-meter a pale face and then decide how many stops brighter it should look over that reading -- you might decide, for example, that you want the face to look one-stop brighter than 18% grey to feel correct, so you'd open up one-stop over the spot metering reading you got.

>If you put a grey card next to a paler face and spot-metered the grey card and exposed for that reading, then the paler face would render as being paler.

In a scene where light falls with different light intensities, where would i place the grey card to measure the exposure? I understand that exposure reading grey card falls in zone V.

I'm saying that the MIRED shift amount for 1/8 CTO are the same for 1/8 CTS, and the MIRED shift amount for 1/4 CTO are the same for 1/4 CTS, etc.

 

So if you want to change the color temperature by the same amount, then you can use the same strength of CTO or CTS -- the difference between CTO and CTS isn't the color temperature, it's the shade of orange, CTS is a bit yellower.

Thank you David.

If your measured exposure from a grey card says f5.6, and you expose at f5.6, then, yes, you have a 'correct' exposure. That doesn't mean that your exposure will result in an image that you like. That is down to artistic interpretation.

 

Skin tone will have no bearing on your exposure if you are measuring from a grey card, just as incident meter readings are independent of the actual subject.

>Skin tone will have no bearing on your exposure if you are measuring from a grey card, just as incident meter readings are independent of the actual subject.

Would a 'white colored' skin looks grey if i expose as said earlier?

CTS is just a yellower shade, less red, of CTO, same kelvin correction / MIRED values for each strength.

 

I should have said "1/8 CTO or CTS" instead of "pale" to be more precise, though the MIRED shift value between 6000K and 5200K is 26, and a 1/8 CTO or CTS corrects with a value of 20, which would lower 6000K to 5376K -- close enough to 5200K.

David,

>same kelvin correction / MIRED values for each strength.

Could you explain 'values for each strength'?

The windows would be facing due south but it would help to have corner windows on the east and west side too if you are trying to get sunlight to fall into the room both in the mornings and afternoons. We are all talking imaginary sunlight anyway, I was just suggesting a way of lighting the same room and justifying hard sunlight in both a morning scene and afternoon scene. You don't have to get too logical or literal about it, I'm just saying that you might get away with it if the sun came in at the opposite raking angles at the two times of day.

Thank you David.

Without controlling contrast in development as in the Zone System you can't really place more than one tone in a specific zone, the rest will fall where they will fall depending on the film stock. So you could place a face in Zone V or Zone VI if you want and meter to see where everything else might fall but the point of the Zone system was to manipulate contrast in development and printing so you can pre-visualize which zones the midtones, shadows, and highlights fall in for the print.

David,

Suppose I put 18% grey card in the a place (where i wanted to place my subject) and measure the light. Say, i got an exposure f/5.6.

If i expose the face of my subject for 5.6 would it be a correct exposure or under exposure? Would it also depend on the skin tone of the subject?

Does it say "cool white" on the LED? Usually that term describes a fluorescent light that is around 4800K with some green in it.

 

I'd just call a 6000K LED "daylight" but maybe the LED industry is reclaiming that name from the fluorescent industry.

 

A pale CTO or CTS gel would lower 6000K to 5200K, or you just set your camera to 6000K to white balance to the light to correct it to neutral. If the LED has some green in it, you'd also need some Minus Green gel as well unless you can correct it with just white balance. You may want, for example, 1/4 CTO + 1/8 Minus Green.

 

"Daylight" in photographic terms tends to be 5500K or 5600K, not 5200K. Maybe you are thinking of tungsten, which is 3200K, or maybe you want something slightly warmer than daylight.

David,

What is the difference between pale CTO, pale CTO and CTS?

Thank you David and Bill.

In the winter on the Northern Hemisphere, the sun takes a lower arc in the sky and is more to the south, so it is conceivable that you could have it hitting the southern side of the house for more of the day than in the summer. Anyway it's still a cheat to some degree, it still rises in the east and sets in the west.

 

For example, here in Los Angeles we think of the streets running on a north-south, east-west grid with the Santa Monica-Venice beaches running north-south... but generally the city sort of sits at an angle tilted south-west. So in the summer, the sun doesn't set over the Pacific Ocean, it sets over the Malibu mountains to your right if you are at the beach in Santa Monica looking out over the ocean. But in the winter, with the sun more in the south, it does set over the water.

Thank you David.

So for both season(summer and winter) it is easy to perform a cheat by imagining a southern arc to the sun.

'Imagining a southern arc to the sun', Does this mean the kitchen is located in North-South direction with no windows towards east/ west but windows towards south-west direction?

I guess the first question is whether you want the sun to beam in the morning or the late afternoon because if this whole story takes place in the kitchen, it would be an obvious cheat for the sun to rise and set out the same window. If the room has a corner with windows at a right angle to the main windows, then you could imagine a southern arc to the sun where it comes in from one angle and later from the opposite angle.

 

So without the sun separating morning from midday, or midday from late afternoon, it's a bit hard to make it that clear of a difference though in real life, there might not be a clear difference. You could suggest a hazy morning with more of an overcast feeling and a few room lights on, and then clear weather for the rest of the day with the sun beaming in more and more near sunset.

David,

> If the room has a corner with windows at a right angle to the main windows, then you could imagine a southern arc to the sun where it comes in from one angle and later from the opposite angle.

Could you explain 'southern arc' and 'sun where it comes in from one angle and later from the opposite angle'?

 

I usually shoot a Macbeth color-chart at the head of each roll - which has neutral grey on it - and ask for a one-light work print when I send it to the lab because if I have it fully timed (same as "best light,") the timer is adjusting the printer lights for each scene rather than setting them once and going by the index mark (color-chart) that I set at the head of the roll. Unless my ASA rating was completely off for a given roll, a one-light print is usually enough of a gauge to see what you got. Plus, sometimes you want to see things uncorrected before you start making corrections.

 

There was one time where my exposure was off when I lit the color-chart and I'd asked for a one-light print. So the entire roll was under-exposed and I had to get a timed print made, which can be costly (I still edit on 16mm film.) Short of that kind of issue, I usually save the timing until the final grade. But it all depends on what will be best for your project, aesthetically and financially.

Bill,

>and ask for a one-light work print when I send it to the lab because if I have it fully timed (same as "best light,") the timer is adjusting the printer lights for each scene rather than setting them once and going by the index mark (color-chart) that I set at the head of the roll. Unless my ASA rating was completely off for a given roll, a one-light print is usually enough of a gauge to see what you got. Plus, sometimes you want to see things uncorrected before you start making corrections.

Could you explain,

'ask for a one-light work print'

'going by the index mark'

'Unless my ASA rating was completely off for a given roll'

The orange color mask is in the camera negative, the interpositive, and the dupe negative -- it allows the colors in the print made from a negative or dupe negative to be more accurate. So it is not "removed", it's just that the print stock is designed to compensate for the color mask in the negative or dupe negative. I could say that the print stock "corrects out" the color mask in the negative but in truth the color mask helps get better color reproduction so I don't think the word "correct out" is correct.

Thank you David.

"Full Aperture" just means the largest possible usable area of the negative for whatever format you are talking about -- sprocket row to sprocket row in one direction and the frame lines in the other direction.

 

The blow-up + squeeze from 2-perf spherical to 4-perf anamorphic maybe would be more clear to look at these illustrations:

 

In this drawing of the 2-perf frame, this is the classic Techniscope format where the camera did not expose image into the soundtrack area (the grey stripe area on the left edge) since it didn't need to, because if it did, that would be a 2.66 : 1 image.

 

The 4-perf 35mm anamorphic format does not use the soundtrack area on the left for picture either, since it is a projection format (meaning there is a soundtrack on the print.)

Thank you David. Now I got it.

Tungsten light is most certainly not a broken spectrum-- it's why it's the most pleasing light to light with-- all other lamps, however, discharge as they are or LED most certainly DO EMIT a broken spectrum. A Tungsten filament is a VERY good analog for a Plank Black Body Radiator, and yes, full CTB is designed to bring 3200K to 5600K.

Thank you Adrian.

Not quite...

See this link:

http://www.cinematography.com/index.php?showtopic=3529

Daniel,

I have gone thru that link, but able to find answer for my question.

'Is full CTO and full 85 correction different or same?'

Yes, more or less. Full CTO actually is warmer than an 85B filter so it probably loses a little more than 2/3's of a stop, closer to a full stop probably.

 

Full CTO converts 6500K to 3200K (Mired Shift +159).

 

An 85B filter converts 5500K to 3200K (Mired Shift +131). The equivalent gel is Sun 85. You could also try 3/4 CTO, which has a Mired Shift +124.

David,

What is the filter number for Full CTO?

Is Sun85 filter and 85B filter produces same results? Both are from different manufactures ?

I use practicals to light the talent IF they are sitting very close to the practical, because then the exposure difference between the face and the lamp shade is not so extreme, and if you are shooting with a camera with a wide dynamic range such as an Alexa, you shouldn't have a problem holding detail in the bright areas. I just saw "A Most Violent Year" and there's a night shot of Jessica Chastain sitting at a desk lit by a gooseneck desk lamp with a large dish shade, and the Alexa was holding detail inside the white dish near the bulb. Her key is coming from the desk lamp, though she is filled by an ambient soft ceiling light.

 

It also depends on your mood, there are scenes in "A Most Violent Year" where a room is mostly lit with practicals and the shot is exposed so that most of the interior and people are near silhouette, so the lamp shades, curtain sheers, etc. are all holding detail fine.

 

Anyway, to address the first question, you don't need to use daylight film in tungsten light to get a warm tone, people have been getting warm tones inside at night in movies using tungsten film for decades. You could use daylight film but that would be like putting full CTO on all your lights or a full 85 correction on the lens, it's quite orange, and once you try to color-correct some of that out, you'll find that there is hardly any exposure in the blue layer, which may create some desaturation once corrected, like working from a sepia-toned image. I mean, it's been done in some movies -- "Eternal Sunshine of the Spotless Mind" is one example, the tungsten interior work was shot on Fuji 500D Reala -- but it's not too common. It's more common when you plan on lighting the foreground with HMI's or close to daylight-balanced light and want to let a tungsten background go orange in comparison.

 

What I do is shoot the grey scale / card before the tungsten-lit scene with a 1/4 CTB gel on the light hitting the grey scale / card (or a pale cooling filter) -- once the colorist corrects the grey to look neutral, then the tungsten scene that follows will look warmer. Also, after the grey scale / card, I shoot a sign that says "COLOR: WARM GOLDEN TONE" or something like that so that the colorist knows that the scene that follows the grey scale is supposed to look warm.

 

Also, I wouldn't be afraid of using 2700K household bulbs, you just have to put some 1/8 or 1/4 CTO on your movie lamps to match or slightly dim them down.

David,

>You could use daylight film but that would be like putting full CTO on all your lights or a full 85 correction on the lens, it's quite orange, and once you try to color-correct some of that out, you'll find that there is hardly any exposure in the blue layer, which may create some desaturation once corrected, like working from a sepia-toned image.

Is full CTO and full 85 correction different or same?

When shooting at night, the light coming through the window doesn't need to be a very powerful unit. As David mentioned, a lot will depend on your power source. Mole, litepanel, Desist all make "2k" Daylight LED lights, which will give you a very nice blue through the window without gel and using only around 900 watts of power. There are also the Bee Hive plasma lights which are bright and use low wattage. For the fire, you could use two inkies or 150w fresnels on the floor, one with half CTO and one with a stray color. You can run them through a flickerbox or use two hand dimmers and have someone just dim them up and down erratically - never letting either go below 50%. Balance for for 3200, unless you want the blue less saturated. But remember, in real life moonlight is around 5600k and our brains have balanced our vision to something around 2,800k. So letting the blue be blue is actually more natural.

 

The main question is what is the emotional content of the scene? Is it frightening? Sad? Romantic? Each one would be lit sightly different, changes in the contrasts and whether you're adding kicks or backlight. Do you want the rest of the room to fall off into an unknown black oblivion or be a safe haven for the characters?

David,

>The main question is what is the emotional content of the scene? Is it frightening? Sad? Romantic? Each one would be lit sightly different, changes in the contrasts and whether you're adding kicks or backlight. Do you want the rest of the room to fall off into an unknown black oblivion or be a safe haven for the characters?

Yes. I want the rest of the room to fall off into an unknown black oblivion or be a safe haven for the characters. This because the characters in the movie just escaped from police.

I am attaching my plan as a diagram.

The type of the light source for the moonlight would also depend upon the set. Do you have any pictures you can post?...

 

As for the color temperature, I'm assuming you'd want the fire to look orange and the moonlight to look blue. So you can achieve this a number of different ways, but it all depends on what kind of look you are going for. How blue do you want the moonlight to be and how orange do you want the fire to appear? What will be the dominant color(s) in the palette?...

Bill,

The background of the story is 3 characters are suspected as a part extremist group but in actual they are not. While coming back to their village after watching a movie, police try to chase them and protagonists finally reach an abandoned house. There the short film starts from there. How they ended up there would be revealed in the story by dialogues.

The building have 2 windows.

I am thoughtful about the patch created on the floor by the moonlight. The protagonists would sit in that patch, make a campfire discuss things.

So the light sources I could think about in that situation are

1. moonlight cumming thru windows and

2. fire

Apart from that I think I need some to provide a visibility of the room. As the story is in progress, the protagonists would move around the room.

Do you realize that the correction for 3200K to 5500K loses you 2-stops, whether it's full blue gel on tungsten lights or a full blue filter on the camera? At some point, it may be worth the money to rent some HMI's and daylight Kinos and LED's.

 

Yes, to match daylight, your tungsten lamps will need Full CTB gel. However, you can only partially correct the tungstens if you want a warm light afternoon sunlight effect, or leave them uncorrected for an sunset orange look.

 

You don't need a warming filter if shooting in the shade, you can fix that in post.

 

Why are you shooting in color reversal film? It doesn't give you much latitude for correction. Is this for a fantasy or flashback effect?

>Yes, to match daylight, your tungsten lamps will need Full CTB gel.

My understanding is tungsten lamps emits broken spectrum. Does CTB gel converts 3200K to 5600K?