Using coloured charts aka Jason Cole

[cookey]

I am a newbie & have geen watching & learning as much as possible & have seen photographers using a chart with 24 different colours as I have seen as per Jason Coles photographs.

http://www.jasoncolephotography.com.au/_models_site/featured_models_gallery.php?t=Behind_the_Scenes&id=128&page=m_behind_the_scenes

Was wondering the reasons behind using the coloured chart please?

[FlyingPhotog]

It's generally called a "Color Checker" and it's invaluable for situations where a photographer and/or his or her client want a color or colors to be an exact value. This is something that trancends even a correct White Balance.

Using R, G, B values, "Red" is R255, G0, B0. But what if the client says, "Our red swimsuit for 2009 is R250, G2, B3. With a color checker and the eyedropper tool in processing, you can tweak individual colors to exactly the values the client wants.

They can be expensive to buy, but only being able to guess at color values when shooting for a client can get even more expensive fast!

[cookey]

ok thanks for the explanation

[Coastwatch203]

FYI, the only colour Jason uses on the whole color card is the 18% grey square.

This is done so a custom white balance can be used in camera.
And after wards if required in lightroom/photoshop etc .

In the simplest "dumbed down" terms the custom white balance derived by color picking the 18% grey square ensures that "Whites" appear white, and not yellow, cream or any other color - same for blacks, etc etc.

Mainly used when artificial lighting is used, such as soft boxes, flash etc.
(have you ever seen inside flash photos which had a "yellow cast?" - if a grey card was used, the color cast problem could be resolved.)

(other reasons as Flying photog mentioned as well - but i do know JC only uses the 18% grey square as he mentioned it in a post a while back)

I suggest you check your camera manual regarding "custom white balance" and also google how and why set a custom white balance.

Hope this helps:)
Mark

[cookey]

ok ,
I do a custom white balance & take a pic of the grey card using my light set up.
I thought he might be doing something else with all those colours.