This guide will walk you through the process of achieving perfect white balance for any photograph. An accurate white balance is crucial and is the best way to get rid of unwanted color casts.
Step 1:
In Adobe Photoshop select the Threshold option from the layer-adjustment drop down menu of the layers palette.
Step 2:
The goal of this step is to find and mark the brightest point in the photograph. Slide the arrow to the right until you barely see any specks of white. Hold shift and click one of the white areas. Notice a reference point appears where you clicked. Keep the Threshold tool open and continue to step three.
Step 3:
Do the same thing for the shadows by moving the arrow left and marking a black area. Now you can click Cancel to close the dialog box.
Step 4:
Select the Curves option from the layer-adjustment drop down menu of the layers palette. Note: You could bring up the Curves option by pressing Command + M for mac or Ctrl + M on pc, but that would be destructive to the image (could not be undone in the future). I'll make a tutorial on non-destructive image editing soon.
Step 5:
This is the step where the magic happens. All that is left to do is select the white sample-point tool and click the lightest area in the imagethe sample point we made in step two. Repeat this with the black sample-point tool and the darkest area. Click Ok to close the dialog box and you're done!