This is a continuation of the post, “Gray card: Why your meter may be lying to you!” at:
I’m putting it in a separate thread ‘cause the pic is 100K.
There’s a lot of talk about what’s best for exposure, Gray cards, white paper, expensive attachments for the lens. I hope to put that to rest here. Draw your own conclusions, but a plain piece of paper does it for me.
The white 'card-paper' has an advantage in low light situations which is explained in the data sheet that came with my card - it's easier to get a reading since it is brighter.
Take a reading of the white card/paper. Center the meter & take a picture at that setting. You'll see the histogram is concentrated in the middle - just where you want it. Use that shot to set your WB.
For the exposure setting, open up ABOUT 2-1/3 stops & take another shot. Chimp the exposure so it almost touches the right side & set it in Manual mode. Done in less than a minute.
That might seem like a lot to do to get the exposure, & it is, but we can simplify the process. There's an example of using your hand instead of white paper for exposure in this thread: Need an exposure crutch?
NOTE: Make sure that you haven't included ANY reflective highlights in the pic (Sky, chrome, etc.). They WILL throw off the exposure!
(Unless it's the sky that you want "properly" exposed, that is!
More on how the subject affects the exposure in Post # 47
EDIT: Jon made a comment in another thread that has some merit, so I'm adding it here:
"For instance, many papers contain UV brighteners, so that neutral white paper you selected by comparison with three other sheets of paper under your desk lamp (2900 K) will almost fluoresce when you bring it out into a strong UV source, like a sunny day, thus giving a strong colour imbalance. That's why using a commercial, neutral, grey card is preferable. In fact, it's what Canon is currently recommending."
That's true. Still, I rely on RAW & RSE to make final adjustments to the WB on post-processing, so I ignore that excellent advice!
I still use cheap, bulk, printer paper most of the time. I always have it with me to take notes on. Quartz lighting indoors shouldn't cause any UV fluorescing, and the cam has a UV filter, but I'll run some tests with a Kodak white card vs. the brand of white paper & the lighting I'm using at the time (flash or daylight). Maybe you should, too.
Re-edit: Here they are: