How do you set the meter with a grey card

[preacher]

I am attempting to get familure wth my Digita Rebel my manuel is telling me to hold the card in front of the camera, but is that all you do to get a reading or do I push certain buttons turn certain wheels? and after you get the reading what do you do?

[scottbergerphoto]

You can start with this thread from yesterday:
http://www.photography-on-the.net/forum/viewtopic.php?p=350767#350767
You can also do a searech above on "grey card".
Scott

[preacher]

Thanks for the link but nothing in there tells me how to set the meter on my digital do I simply put the card in front of the camera and look at the numbers that come up or do I turn something on the camera?

[emilbev]

If you want to use a gray card for setting your exposure in the field you should do the following.
-Look through your view finder and fill the frame with the gray card.
-Mark down and remember the exposure reading (aperture and shutter).
-Set your camera on Manual Mode and dial in the numbers (aperture and shutter) that you got from the gray card exposure.
-Then take your picture.
Good Luck

[DaveG]

I am attempting to get familure wth my Digita Rebel my manuel is telling me to hold the card in front of the camera, but is that all you do to get a reading or do I push certain buttons turn certain wheels? and after you get the reading what do you do?

Your meter works in a funny way. It thinks that the entire world is 18% grey. If the subject is a black door, your meter thinks that it's an 18% grey door, but without a lot of light on it and will give you a meter reading that will take the perfectly happy black door and will make it 18% grey. It works like this for white too. A white door is viewed by you camera's meter as being 18% grey as well, but with lots of light on it. In theory if you meter a white door and a black door and follow the meter you will get two identical exposures.

In real life almost nothing is all white or all black, but rarely is is 18% grey either. 18% grey is a number that the film/camera companies have come up with to represent average, and most scenes that you photograph will be average. But some photographers prefer to do their meter readings by basing them on an 18% grey card which can be a stand alone card or found in something like a Kodak Darkroom (or Professional) Photoguide.

You fill your camera's frame with the grey card, while being very careful to keep the card in the same light as your subject. You do your metering on a manual setting so the camera won't automatically change the aperture or shutterspeed when you remove the greycard. You "centre the needle" in your camera's meter. Remove the grey card, don't change the aperture or shutterspeed and shoot the real subject, but now you ignor what the meter is trying to tell you.

There is a chance that you might have a problem with highlights blowing out if you use this technique. You are metering for dead middle tones and are hoping that the digital capture has enough latitude to hold the bright highlights. Check your histogram after a test shot to see if the highlights have clipped or if they are highlights you care about. A grey overcast day photo with lots of sky will have blown out highlights since you'll either have to expose for the sky or the subject.

Your test shot of the 18% grey card can also be useful for getting the white balance later. If you shoot RAW you can take another test shot and in this one I would try to include more of the scene, rather than having nothing but grey card. Do an exposure adjustment in Photoshop RAW (or the Canon RAW softtware) and then bring it into the regular Photoshop. Don't mess with colour adjustments in Camera RAW or this next bit won't work.

Enable the INFO pallet and then get the Color Sampler Tool - it's behind the Eye Dropper Tool on the Tool Pallet.

Hold the curser over the grey card and click the colour sampler tool. Look at INFO. There should be a number 1 and then three numbers after R, G, B. If these numbers are all the same then you can stop and go on with something else.

If they are different open up Layers/New Adjustment Layers/Colour Balance, and click OK. You'll see a dialog box with Colour Balance written on the top, and some sliders. The midtone radio button should be enabled and that's what we want. With the INFO dialog box still open start to change the cliders so that the red, blue, and green are all the same number.

What you've done is made sure that there's NO colour cast in the mid tones. I use a grey scale patch from an old Kodak Professional Photoguide and use three targets, a white, mid grey and a black so I can get the INFO for highlights, mid tones and shadows. Just using a single grey scale is inexact but better than trusting your eyes.

Now I've clicked OK on the Color Balance dialog box and have a white balanced test image.

I leave this test shot open and move on to the first "real" shot. In Camera Raw choose Previous Image and go into Photoshop proper. Because you made the colour balance adjustments as a layer on the test shot it's independent of the image (for god's sake don't flatten it!) and you can now drag the adjustment later onto the face of the new shot! No fuss, no muss and as long as the test shot and the other shots were done in the same light then it should all work well.