Using a grey card correctly

[Eugene Lehnert]

If I have a wide shot of a scene that uses a lot of different lights in the scene how do I use the grey card with a spot meter?

 

I have the main subject in a chair reading with a lamp in a dark room with splashes of light in corners and some coming in through the window at dusk. Should I place the card near the subject under the lamp? How do I make sure I represent proper skin tones? Should I get proper skin tones once I figure out my f-stop for the grey card?

 

Can I then use the spot meter to look at the scene and find out how many stops parts of the room are over or under from the neutral grey?

[Sam Wells]

Typically yes at the principal subject.

 

It's usually reccomended to angle the grey card from the meter, but in a lighting setup, honestly I generally read on and off perpendicular. I want to know what the geometry of the lighting is doing.

 

(compare using an incident meter with its hemisphere, not coincidentally face-like)

 

The skin tones should fall into place if you do this right.

 

Yes then you can use the spot meter to see the rest of the room as you describe.

 

-Sam

[Eugene Lehnert]

Ok, so if I take a reading with an incident meter pointed at the camera by the subject's face I should have an f-stop about half a stop down from the reading off of the card?

 

For instance if I had 4.0 on the card from the spot meter would the incident (with hemisphere) give me an f-stop halfway between 2.8 and 4.0? Then if I took a reading of the subject's face, say an average irish man without a tan I should get a reading about 5.6 or between 5.6 and 8?

[John Pytlak RIP]

The Kodak website has suggestions on the proper use of a gray card:

 

http://www.kodak.com/US/en/motion/products...tographer.shtml

 

http://www.kodak.com/US/en/motion/products/tools/card.shtml

[Eugene Lehnert]

I was looking at the Kodak website. I just wanted to see if I was understanding everything correctly.

 

From what I understand incident light meter readings are based on a 13% grey instead of the 18% that a reflective light meter is calibrated to.

[Stephen Williams]

I was looking at the Kodak website.  I just wanted to see if I was understanding everything correctly. 

 

From what I understand incident light meter readings are based on a 13% grey instead of the 18% that a reflective light meter is calibrated to.

<{POST_SNAPBACK}>

 

Hi there,

 

A spot meter pointed at a grey scale may well give you a different reading to an incident meter for that reason. Hovever I use a spot meter to measure the contrast in the scene and then decide where to place the exposure based on how I want the image to look.

 

Stephen Williams DP

Zurich

 

www.stephenw.com