Should I be warming grey card calibrated shots?

Question

In a recent blog post at this site, Tim Grey recommended the following:

You could then use the white balance tool in Lightroom or Adobe Camera Raw (or similar tools in other software) to make the gray card appear perfectly neutral, and then simply adjust the Temperature slider to shift between blue and yellow. For the “typical” photograph that would involve increasing the Temperature value to add a little warmth to the image.

After reading other questions about using a grey card on this site, I do not see anyone else recommending "adding a little warmth" back in after using the white balance tool off of a grey card. Is this a typical practice? Do grey cards produce cooler colors then most scenes require?

Answer 1

I usually find, especially when dealing with artificial light, that an image that is white balanced that accurately is often cool and I tend to find it a little harsh as a result, so I've been known to warm up the image a little either with the white balance tool or a filter in Photoshop afterwards.

I would note that it wasn't all that rare with film, which was white balanced for appropriate light, to use warming filters to make it a little more pleasing, especially with people in the image. Cooling filters also existed, so it is entirely dependent on the look you want to achieve as to how you would filter.

At any rate, skin tones tend to look better if the blue is minimized...

Answer 2

It's all about intent and artistic vision.

In studio lighting, for example, getting a perfectly white-balanced shot might be very important because the colors of your client's product need to be exactly right. You would never want to warm up (or cool down) their logo color, for example, in a product shot. Use the gray card to achieve correct white balance, and don't change it later.

On the other hand, when you're outside in the warm sunset light and want to shoot a portrait, getting "correct" white balance will remove that warmth. You want that red warmth because it's what makes the scene so special. In this case, you might use the gray card and as-shot white balance to remove an undesirable green tint, for example.

In another scene, your as-shot white balance might be pretty accurate. You shoot with the gray card, and in post decide the gray card's white balance is slightly better than the as-shot white balance. But, gee, it needs just a touch more red to be perfect so you adjust the temperature slightly.

It's all up to you.