Grey Card

[CHE]

So...

 

I am going to film a short on 16mm. Do I need to film a grey card at the head of each lighting set-up? I only ask because I have gotten seriously burned by not using one. Will it help that much if I do use one...and how often would you recommend that I film it? Thanks for all of your help.

[David Mullen ASC]

It just depends on the color balance you want. If you shoot the gray scale under flat "white" light (3200K for tungsten balance stock / 5500K for daylight balance stock) at the ASA rating you have chosen to work at, then anything that follows on the camera roll where you used colored lighting or deliberate under and over exposure should be retained because once the colorist sets the transfer for the gray scale and then sees a scene lit orange or blue, or very underexposed by design, they know it's all intentional.

 

So you only need to shoot a gray scale once at the head of the day unless you change film stocks. All the camera rolls can refer to the first gray scale, assuming you number the camera rolls.

 

You'd shoot a new gray scale when you switched stocks and lighting balance, like going outside in daylight after being inside under tungsten lighting.

 

The only time you'd shoot a new gray scale for a new lighting situation is if you wanted to deliberately have the color timing changed away from normal. The most common example is when shooting everything under greenish fluorescent lighting and you want them to remove the green in post through timing, so you shoot the gray scale under that greenish lighting and once they correct it to normal, the following scene should look normal. However, if you wanted the green, then shoot the gray scale under "white" light first.

 

I usually follow the gray scale with a sign that tells the colorist my intent: COLOR: WARM FIRELIGHT or COLOR: DEEP BLUE MOONLIGHT or COLOR: KEEP UNCORRECTED GREEN FROM FLUORESCENTS.

 

I've also gotten the image timed other directions by shooting the gray scale under the opposite color I want. For example, I recent shot a bunch of daylight scenes where I shot the gray scale with a piece of 1/4 Blue gel over the camera, then pulled it for the scene, which then looked warm because they had added orange to the image to make the blue-ish gray scale look neutral, sort of like tricking out the white balance with a video camera. This saves me from having to use pale warming filters on the camera, etc.

[Robert Edge]

David,

 

Do you use a GretagMacbeth card and, if so, in what circumstances?

[CHE]

David...

 

Thank you very much for your detailed reply. I very much appreciate all of your expertise.

 

Sincerely,

[David Mullen ASC]

No, I don't use a color chart because color is subjective, whereas gray is not. Most people can agree when a gray scale or card is too pink or blue or green, whatever, but most people cannot agree what the individual squares of color on a MacBeth chart really should look like.

 

I only use color charts for shooting tests.

[John Pytlak RIP]

A gray card is always useful, if only as a communication tool. But if it is not lit or intended to be gray, be sure the color timer/colorist knows that:

 

http://www.kodak.com/US/en/motion/products....4.10.8.4&lc=en

[Laurent Andrieux]

gray or grey ?

[Charles MacDonald]

gray or grey ?

British or American? its like some folks write a check or a cheque.

[Dominic Case]

gray or grey ?

This is one of a small collection of words which the English language spells in either way, both are quite correct. Grey is more common in the UK, gray more in the US - but it's not a hard and fast rule.

 

Interestingly, the Oxford English Dictionary says (in part):-

 

Many correspondents said that

they used the two forms with a difference of meaning or application: the

distinction most generally recognized being that grey denotes a more

delicate or a lighter tint than gray. Others considered the difference to

be that gray is a _warmer' colour, or that it has a mixture of red or

brown (cf. also the quot. under 1 c below). In the twentieth century, grey

has become the established spelling in the U.K., whilst gray is standard

in the United States.

 

Isn't English a weird language . . . (Laurent?)

 

Note that the recent US TV show "Grey's Anatomy" misquotes the seminal medical textbook "Gray's Anatomy" first published in 1858.

[Laurent Andrieux]

Thanks very much indeed for such a documented answer !

[Matt Pacini]

I have glued a gray card to the back of my slate.

I shoot a gray card at the head of every roll of film, but then, I'm a paraniod!

It only takes a few seconds to do this, so I figure , why not be safe?

MP

[John Pytlak RIP]

Kodak Gray Card Plus:

 

http://www.kodak.com/US/en/motion/products....4.10.8.4&lc=en

[Matt Pacini]

The other thing I do, if I think the lighting is a bit weird, is I'll get the person who has the best skin tone to hold the graycard next to their face, so the colorist can see good flesh-tone as they're adjusting.

I know, not very scientific, bu everything helps I figure!

MP

[Laurent Andrieux]

I think colorists like a skin tone reference even better than a grey card ! Usually, the best to do is to have both as you do, though I prefer putting a 6 zones (black to white by steps of 1 stop) card, close to the talent or person I shot, better than anybody even with the nicest skin I can find...

[Vivian Zetetick]

Just out of curiosity, how is the grey card information useful if your camera negatives are A-B rolled and an interpositive struck? I would assume that after the A-B rolls are assembled, there is no longer a way for the timer to reference the grey card shots. Is the grey card only useful for dailies and digital intermediates?

Edited November 4, 2005 by VivianZetetick

[Laurent Andrieux]

Is the grey card only useful for dailies and digital intermediates?

 

Well, somehow, yes...

 

After the editing is done on this basis, the real timing occures, regardless to the reference. But it's not the same problem...

 

The need for the first color timing is different because neither the DOP nor the Director can supervise them, since they are still shooting... and the lab as a short time to give a positive.

 

Usually this first setting is good enough for the editor to work with.

 

Afterwards, when it comes to final timing, the DOP can be there and more time can be spent on a more precise work.

 

But this work doesn't need a reference card. What people (DOP, director, color timer) are looking for is an esthetic, a "look". The audience won't have a reference grey card in the theater neither. For what is about television, neither will the consumers have a waveform monitor to evaluate the image's quality.

 

We're not looking for a norm's respect, after some point, we're looking for a look. The norm is supposed to accept some different looks... not the opposite. The norms serve the esthetic, not the opposite...

 

how is the grey card information useful if your camera negatives are A-B rolled and an interpositive struck?

.

 

A/B rolls editing nor IP has much to see with this...

 

The eventual intermediates are supposed to be "loseless"... and even if there not, it's all the same along the whole movie, so there's not much to do about it... once again, it's controled by eye, no need for any card anymore...and A/B rolls editing really is "loseless".

[David Mullen ASC]

Is the grey card only useful for dailies and digital intermediates?

 

Isn't that useful enough?

[Charles MacDonald]

Isn't that useful enough?

And the folks timing the final prints, probably can refer to their notes, and if something funny is going on, the workprint, or the cinematographers notes, to get the final to match the desired effect(s)

[L K Keerthi Basu]

Other then these uses I think that GREY CARD is a very good tool for the correct expsoure. Cinematographer can judge his exposure is correct or not, here Iam not taking about the color correction but about the negative density.

 

KODAK GRAY CARD PLUS is a well calibrated 18% gray card, only with this I have learnt about Exposure.

 

Apologise if Iam out of the topic.

 

 

L.K.Keerthibasu

[Laurent Andrieux]

And the folks timing the final prints, probably can refer to their notes

 

Whatever method is used, every shot correction is digitally stored and kept.

[Dominic Case]

And the folks timing the final prints, probably can refer to their notes

There are systems aound where the rushes lights can be stored against the negative keykode, and then when the final cut neg comes back to the grading department they can scan the keykodes of the neg and recall the rushes lights. Supposedly this is a good starting point for the colour grader (timer).

 

In this part of the world it has been the convention for many years to print rushes (dailies) at a fixed light (determined by tests before the shoot). This combines a lot of benefits.

 

It is quicker

It is cheaper

It is better

 

Yes! like the perpetual motion machine, here is something that gives all three of those things they said you could only choose two of.

 

The "better" part is because the rushes print shows exactly what the DoP lit and shot, not what the night shift grader thought it should look like.

 

If there are any exposure problems, you can see them right away instead of having to decode printer lights.

If there is any effects lighting, it still doesn't do any harm to shoot s standard grey card at the front just as a confidence check.

 

Unfortunately, it is now rare for any negative to be workprinted at all, so this argument loses ground!

[Robert Hughes]

I was taught that Gray is somebody's name and Grey is a color. But that was Ohio, 40 years ago.

[Sampsa Huttunen]

I was taught that Gray is somebody's name and Grey is a color. But that was Ohio, 40 years ago.

Yes. That was Ohio. :)

Gray is a color, but grey is a colour. American vs. English.

Edited November 6, 2005 by Sampsa

[Will Montgomery]

Yes. That was Ohio. :)

Gray is a color, but grey is a colour. American vs. English.

Not sure if its quite that black and white... it's really a grey area.