Why A Gray Card Is Still Useful

With the camera technology we have available to us today you might think that the use of a gray card is no longer necessary. However, it can still be an invaluable tool for professional photographers and keen amateurs alike when trying to produce accurate colour reproduction on screen and in print. 

In the days when film cameras were the models of choice, more advanced photographers used gray cards as a way to achieve accurate colour balance by including the gray card in the scene so the lab they sent the film off to could adjust filtration and prevent any minor colour casts. With digital photography gray cards can still be used for the same reasons but instead of sending the images to a lab, you can adjust them yourself in various pieces of editing software. 

For accurate editing at home, you need to take a shot while out on location which shows the gray card in the scene (shooting in auto white balance is fine but if you know the type of light you're working with, feel free to choose one of the other white balance settings available) then once you're in front of your computer, the editing software you use can read the data from the coloured pixels on the gray card to determine the correct colour balance for the shot. This also means that you can batch process all images taken in the same lighting conditions rather than spending extra time working on them individually. 

If you like to edit in Photoshop and shoot in RAW you can use the 'white balance' eyedropper tool to correctly set the white balance of your shot. Just click on the gray card held in shot and the other colours will change in relation to this point of reference.
With multi-image Camera RAW, these settings can then be applied to as many images, taken at the same location in the same lighting conditions, as you choose by selecting 'Synchronize'. In Lightroom, when working in the Develop module, you can use the white balance eye-dropper tool to, again, click the gray card in the image. This will change the 'Temp' and 'Tint' values listed which you can make a note of and then apply to the other images you've taken. If you have quite a few images to work through which were taken at the same location and / or in the same lighting conditions it can be worth creating a Preset. 

To learn more about colour management, take a look at the techniques and articles available on EIZO ColorZone.

If you want to take a look at a range of monitors designed with colour management in-mind, take a look at the EIZO website.