The following images were shot with diffused light from a light box, 5500K light source. The auto bracketing feature was enabled on the Canon DSLR.
A two stop variation was used in this case. The first is the normal exposure read by the meter and the second underexposed by two stops and the third 2 stops overexposed.
This flat watercolor illustration was shot with a one stop exposure variation. The EV was also set for a two-thirds overexposure due to the amount of white showing on the camera’s meter.
The final image was shot with the contrast setting in the camera set higher and the last overexposure settings used. A small adjustment in Photoshop, Brightness/Contrast was made (and the black edges were cropped out).