Grey Card / White Balance

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rhodopsin

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How do you actually use an 18% Grey Card to set the White Balance on a Digital SLR ?
 
Place it in the light/environment that you will b shooting, take an image of the grey card.

In your menu go to Custom WB, set image to the grey card, job done!
 
EdBray said:
Place it in the light/environment that you will b shooting, take an image of the grey card.

In your menu go to Custom WB, set image to the grey card, job done!
Click to expand...

How do you set the image to the grey card ? What process on the camera is undertaken to correct the white balance ?
 
rhodopsin said:
How do you set the image to the grey card ? What process on the camera is undertaken to correct the white balance ?
Click to expand...

Don't know as you've not said which camera you are using!

It will tell you in the manual!
 
For Canon, take a photo of your 18% grey card, or a white one,under the lighting you are in. go to the camera menu and select "custom WB", and press the "set" button. Scroll through your images til you get to the one with the card and press the "set" button again. Select OK and quit the menu system. You now need to set the camera shooting WB to custom. Press the "metering mode/WB" button on the top. Adjust to the custom WB sybol. Shoot pics - If in RAW you can use the shot with the card and the dropper tool to fine tune in ACR.
Webby
 
rhodopsin said:
Yes I know but the manual only states a white surface.

I'm enquiring about grey.
Click to expand...

It's no different, but you have to be sure the grey is neutral, other wise you will impart a cast into your images.

A grey card is specifically designed for exposure not white balance so different cards have different tones but with a similar exposure value.

Many grey cards have a white side too, use that for the white balance.
 
Canon recommends a white surface, however you can use a grey card in exactly the same fashion and the camera still works out the correct white balance for you. You don't need to indicate that you are using grey rather than white, the camera does not care.
 
from my manual (5d but sure other Canon are similar)( in the grey info boxout) "Instead of a white object, an 18% grey card can produce a more accurate white balance"
Webby
 
Fragglerock said:
Canon recommends a white surface, however you can use a grey card in exactly the same fashion and the camera still works out the correct white balance for you. You don't need to indicate that you are using grey rather than white, the camera does not care.
Click to expand...

Cheers (y)
 
You can use any 'neutral' subject - one that is known to have equal amounts of red, green and blue in it. The camera then analyses that image and sets the white balance so that red, green and blue are exactly equal. If you have a colour histogram option, you will see all colours adjusted to the same level. In this way, all other colours in the picture will come out accurately.

The main advantage of using a white target is that there are quite often neutral white targets around so you don't need to carry a card specifically. I used a table cloth the other day, which I think is popular with wedding photographers.
 
grey card for exposure in the light you are shooting...or your hand
 
i use one of these caps - works a treat !

L4C_show.jpg
 
mrcrow said:
grey card for exposure in the light you are shooting...or your hand
Click to expand...

A hand may be ok for setting the exposure, but it's no good for setting custom WB. To do that you need an object that reflects red, blue and green in equal amounts, which a hand wouldn't do.
 
rhodopsin said:
Yes I know but the manual only states a white surface.

I'm enquiring about grey.
Click to expand...

i think Canon like to take a white card for wb in camera but best to shoot in RAW and tahe a shot of the grey card and in acr set you wb there
 
Do you have to fill the frame with the card? If so, doesn't it mean having to use a large card?
 
coldpenguin said:
Do you have to fill the frame with the card? If so, doesn't it mean having to use a large card?
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No, with Canon you just need to fill the centre circle.
 
I use the inside of my Lowepro bag. :)
 
I just had a quick play using webbEvents instructions and the difference between the same shots taken on the awb and custom settings is dramatic, the 18% grey been the inside of my Lowepro bag (y)
 
Walt said:
I just had a quick play using webbEvents instructions and the difference between the same shots taken on the awb and custom settings is dramatic, the 18% grey been the inside of my Lowepro bag (y)
Click to expand...

I find that AWB works okay in daylight, and everywhere else it is either next to useless, or completely useless.

Which I guess is why the camera also has a manual white balance setting, a custom setting, and six other preset settings.
 
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