Basic white balance card questions

[kat.hayes]

I have some white balance targets and have a few questions that I'm hoping someone can answer.

1. I have a collapsible white target and on the opposite side it is dark grey. When would you want to calibrate against a grey color?

2. When would you want to calibrate your camera with some blue cards rather than just using lights with blue lights or using blue gels?

Thanks!

 

[Garion]

I know where your coming from, i use one of these to white balance my camera http://www.jessops.com/online.store/products/28987/show.html

i actually get a better white balance from using the grey side over the white.
Some people like to get accurate colour setup in cam then colour it in post whilst some like to use warm or cool cards to set the colour in cam and do a little less in the edit.
e.g. http://www.creativevideo.co.uk/publ...ue_number=vortex_warmcards-complete-2&cvp_com

Maybe someone better qualified than me can comment

 

[maplecap]

It's probably 18% gray; not for calibrating the camera but for reference. 18% gray has been the exposure standard forever, as it "generally" represents an average for skin tone. When you use an incident light meter, it is providing data for 18% gray. You can take a spot meter reading off of an 18% gray card to achieve the same data.

 

[bruce southerland]

White balancing to blue (by blue card or blue gels) is generally done when the cinematographer wants the entire image
to read as "warm", without having to gel the lights that are illuminating the scene. Some manufacturers have cards that
correspond to 1/4 blue, 1/2 blue, as well as 1/4 orange, 1/2 orange. Again, it's a quick way to warm, cool, or color the image
without having to gel all the lights. The camera will balance to the opposite color that's put in front of it. If you color balance
to 1/2 blue, you'll get a 1/2 orange(warm) look. Color balance to 1/2 orange, you'll get a 1/2 blue look. Color balance to magenta
and you'll get a green look.

 

[adanac]

Here is the product we use on our reality show (and which I have just purchased for my own shoot):

http://www.warmcards.com/WC1.html

I have some white balance targets and have a few questions that I'm hoping someone can answer.

1. I have a collapsible white target and on the opposite side it is dark grey. When would you want to calibrate against a grey color?

2. When would you want to calibrate your camera with some blue cards rather than just using lights with blue lights or using blue gels?

Thanks!