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#1 Tom Hepburn

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Posted 15 July 2009 - 12:11 PM

Hello Again,

I'm starting to move to shooting color after working with mainly black and white. I was struck by the cost of a Color Chart?

As usual I'm trying to keep an eye on costs so I'm wondering if this is something that I could put on my "Do It Yourself" list. Obviously, I would need to buy materials, but not sure what kind of "swatches' to get. Has anyone done this? It may be better and more efficient to just buy one, but thought I'd ask the question first.

I should add that although quality is my #1 goal, I'm doing this for my own personal use.

Thanks in advance,
Tom
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#2 Andrew Koch

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Posted 15 July 2009 - 03:35 PM

If you're shooting film and you're on a budget, you could get a simple 18% gray card. They're about 10 bucks. It's not something you would want to make yourself because it needs to be calibrated to exactly 18% so your colorist as proper reference when printing, telecine, or DI. Sure, it would be nice to have a MacBeth chart and maybe black and white chips on your grey chart, but if money is tight, the greycard will work okay.
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#3 Chris Keth

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Posted 15 July 2009 - 03:52 PM

Hello Again,

I'm starting to move to shooting color after working with mainly black and white. I was struck by the cost of a Color Chart?

As usual I'm trying to keep an eye on costs so I'm wondering if this is something that I could put on my "Do It Yourself" list. Obviously, I would need to buy materials, but not sure what kind of "swatches' to get. Has anyone done this? It may be better and more efficient to just buy one, but thought I'd ask the question first.

I should add that although quality is my #1 goal, I'm doing this for my own personal use.

Thanks in advance,
Tom


Sorry to say that, unless you are planning on eyeballing the chart for home color correction purposes, a homebrew isn't a possible substitute. The reason macbeth charts are so expensive is that the printing is extremely tightly controlled so that every color chart in the world, provided it is in good condition, looks the same within pretty tight tolerances. This means the chart you shoot looks like the one on the timer's wall.

Also, the colors on a macbeth chart are significant and very carefully chosen. The first 6 are what color scientists call "memory colors." These are things like the color of blue sky and foliage that, if they are not correct, we will notice very quickly because we see them all the time and they are imprinted in our memories.

The next line down are "gamut colors." These colors lie right outside the edges of most digital color gamuts and are thus difficult-to-impossible to reproduce accurately. These especially would be very difficult for you to print accurately at home. The idea here is to include some colors that won't reproduce properly so you can gauge the difference between your imaging system and the "color gamut of reality" so to speak.

The next line down are the primary and tertiary colors: red, green, blue, magenta, cyan, yellow.

The last is a 6 step greyscale.


The sum of all these color chips creates a system of many graphable, quantifiable points that help you to color manage whatever imaging system you happen to be using. For your purposes, a greycard is all you really need. It is a standard 18% grey and as long as it is timed middle grey and neutral, your footage will look as intended. No, you won't be able to graph your color space against that of the film scanner, computer monitor, or the projector, but were you planning on doing that anyway? ;)
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#4 Phil Rhodes

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Posted 15 July 2009 - 05:20 PM

The reason they're expensive is that they're tightly controlled, as previously mentioned.

The thing about that is - when do you actually need one chart to be identical to another one? Unless you're coordinating with another unit on the other side of the planet (and even then you could mail them a chart you'd produced), what this is really about is shot to shot consistency. Although a purist would point out that inkjet prints fade quickly in UV light (which is true), the idea of one stored out of direct sunlight fading appreciably during any sane shooting period is pretty far-fetched. So yeah, I suspect you could, with care, dream up a chart all of your very own and do perfectly well with it, even if you needed to show it to the colourist (either in person or by providing graded stills demonstrating your desired results).

Additionally, I suspect that even if you were to buy a series of coloured graphic arts materials by someone like Colorama, you'd find that their process control was probably better than the eyes of most colourists. Mike Most will now turn up and tell us that every colourist in the world can, from memory, repeatably grade a Macbeth chart to within a ten-bit code value and if you use anything else a big finger will come down out of the sky and squash you like a bug.

But it won't.

P
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#5 Keith Walters

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Posted 15 July 2009 - 10:55 PM

There's no way you could make one of those charts at home, at least not using an inkjet printer or the like, no matter how many ink tanks it has.
The reason those charts are so expensive is that every colour on them is individually applied using carefully prepared paint-like inks.
If there are 20 colours/shades on the chart, they come from 20 individual tanks of paint, rather like a proper paint colour chart.
You can't duplicate that by mixing together yellow, cyan and magenta from an inkjet cartridge, since the reflectance of the ink base is a factor as well.
High quality grey scales often use strips of black or dark grey felt rather than paint or ink for the darker bars.
There used to be really expensive ones that are actually transparencies made up of individual strips of coloured gel sandwiched between two sheets of glass, but I haven't seen one of those for a while.

Actually on that subject, I was laughing at a 50inch plasma TV (1024 x 768!) with a sticker that proudly proclaimed it has over 2,000,000 to one contrast range!
Wow, you could use that to make a 20-stop greyscale, for a little over $1,000, AND you could also watch TV on it :-)
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#6 Kevin Thomas

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Posted 18 July 2009 - 04:27 PM

Hi Tom,

as an alternative to the macbeth chart take a look at the Kodak Color Separation Guide and Gray Scale pack
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#7 Bruce Greene

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Posted 18 July 2009 - 08:26 PM

Hi Tom,

as an alternative to the macbeth chart take a look at the Kodak Color Separation Guide and Gray Scale pack


This is a good alternative to other more expensive charts.

Don't try printing a chart on an inkjet printer as the colors suffer from metamerism. See this site for a good explanation. Basically it means that a color will appear different when viewed under different lighting. Further a color can photograph a different color than it seems to the naked eye.

I had a good lesson in this recently when I was color grading a movie with some fake grave stones printed with an inkjet printer. It was raining when we shot it and some of the ink washed away :( . The stand-by painter was very good in matching the colors and touched up the damage. In the movie, the inkjet ink appears magenta and the touch up paint appears neutral.

So the lesson is: Always print a back-up gravestone! And, know that inkjet prints photograph a different color than they appear to the eye...
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#8 Saul Rodgar

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Posted 19 July 2009 - 12:15 AM

I would also strongly discourage DYIing a color chart. I got mine from Fotokem for $30 something a couple of years ago, which is the best I have seen for the money. Before that I used a simple 18% gray card. Fotokem's color chart comes folded in a hard plastic sleeve, and includes other essentials such as registration test grids, focusing chart with aspect ratios / and TV safe areas and even some color filter compensating tips and HMI safe speed chart!

Sadly, it looks like their are no longer available, judging by what this thread says.

http://www.cinematog...showtopic=11062

I remember I got mine in the summer of 07, so I would contact Fotokem directly and find out for sure

sales@fotokem.com
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#9 Steve Phipps

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Posted 19 July 2009 - 05:15 AM

I would need to buy materials, but not sure what kind of "swatches' to get. Has anyone done this? It may be better and more efficient to just buy one, but thought I'd ask the question first.

Hi Tom,

I did this, making my own color-chart for a reciprocity test. See here:

http://www.cinematog...h...c=24930&hl=

I agree that it would be "better and more efficient" to simply buy a chart. Counting materials, time invested in construction and research, frustration (the spray-adhesive I used was too weak), I would recommend just buying one. If you take good care of it, you could also sell it later.

The reason I made mine was that I needed to fill a quarter of the frame to be able to get a good reading from the densitometer. The Gretag chart didn't have the right layout, and also, really wasn't large enough. So, I had to make my own chart (mine was more than two feet wide).
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#10 Phil Rhodes

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Posted 19 July 2009 - 06:32 AM

know that inkjet prints photograph a different color than they appear to the eye


Far be it from me to point out the obvious, but surely there wouldn't be much point in shooting them if they didn't...

P
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#11 Tony Brown

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Posted 19 July 2009 - 11:01 AM

Sorry to be thick but why do you need a colour chart when shooting.....? or any other time for that matter unless trying to calibrate two monitor

In 35 years I've never seen one used
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#12 Saul Rodgar

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Posted 19 July 2009 - 03:08 PM

Sorry to be thick but why do you need a colour chart when shooting.....? or any other time for that matter unless trying to calibrate two monitor

In 35 years I've never seen one used


There is a tendency for film crews to not use them often in the real world and for colorists to ignore it altogether in the telecine suite. I have had to resort to filming a note at the head of the roll with the words "Telecine op, please set your levels to the following color chart!"

I like it because I can for, example, underexpose my chart without having to overexpose my footage if I am looking for that effect with the insurance that I can always go back and adjust in post later if I don't like the results or I went too far, etc. The same goes for front-of-lens artistic color filtering, etc.

While most (old) old school cinematographers, telecine ops and lab techs seem to swear by them, a lot of DPs these days trust their knowledge of the stock capabilities, and the colorists, lab techs to do a good enough job without them to skip them. I guess it all comes down to personal preference, but sometimes when I don't use it I feel like I am driving a car without my seat belt on . . . ;)
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#13 Phil Rhodes

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Posted 19 July 2009 - 06:45 PM

Why do we use colour charts? So the grader can ignore them!
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#14 Tony Brown

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Posted 20 July 2009 - 03:28 AM

Why do we use colour charts? So the grader can ignore them!


LOL
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#15 Tony Brown

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Posted 20 July 2009 - 03:32 AM

There is a tendency for film crews to not use them often in the real world and for colorists to ignore it altogether in the telecine suite. I have had to resort to filming a note at the head of the roll with the words "Telecine op, please set your levels to the following color chart!"

I like it because I can for, example, underexpose my chart without having to overexpose my footage if I am looking for that effect with the insurance that I can always go back and adjust in post later if I don't like the results or I went too far, etc. The same goes for front-of-lens artistic color filtering, etc.

While most (old) old school cinematographers, telecine ops and lab techs seem to swear by them, a lot of DPs these days trust their knowledge of the stock capabilities, and the colorists, lab techs to do a good enough job without them to skip them. I guess it all comes down to personal preference, but sometimes when I don't use it I feel like I am driving a car without my seat belt on . . . ;)


Thanks Saul - personally I'd use a grayscale for that - someone once told me if they cant get white right you're in the wrong place. I really cant ever remember seeing a colour chart on a film set......
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#16 David Mullen ASC

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Posted 20 July 2009 - 10:43 AM

Thanks Saul - personally I'd use a grayscale for that - someone once told me if they cant get white right you're in the wrong place. I really cant ever remember seeing a colour chart on a film set......


Same here, the general rule is color charts are for pre-production testing and grey scales are for set work and dailies, the reason being that there's nothing harder than to make a grey chart neutral and we can generally agree when it's not neutral... but no one looking at a MacBeth chart in dailies is really going to agree on if that shade of green or red is correct or not.
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#17 John Sprung

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Posted 20 July 2009 - 02:31 PM

Obviously, I would need to buy materials, ....


Not necessarily. Just walk in to your local Dunn-Edwards, Benjamin Moore, etc. -- and pick from the rack whatever sample cards you like. Glue them to a piece of cardboard, shoot it, and take it to the post facility with you. You can find out for free why nobody bothers with color charts all that much.





-- J.S.
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