Video camera intensity nonlinearities can be corrected without the use of light-measuring equipment or calibrated filters. The camera to be corrected is used to adjust two independent light sources such that they illuminate a test card equally. Digitized images made using these sources separately and together are analyzed to determine parameters for use in generating correction tables. An example is presented in which a ±2% nonlinearity observed in a General Electric model 2507 solid-state camera was reduced to less than ±0.2% using a least squares fit to a third-order polynomial. The technique can be used with camera output having any function (e.g., linear, logarithmic) and should be useful whenever strict adherence to a nominal output function is desired. Simple procedures for determining that a camera is nonlinear and for correction of vignetting also are described.