X-Rite M50103 ColorChecker Gray Scale
ColorChecker 3-Step Grayscale lets you balance your images, plus simplifies the task of balancing your studio lighting.  A white, 18% gray and a black target all on a single card make color adjustments faster and easier with your photo processing software.  Simplify camera and studio lighting balance with this three step gray-scale target for performing quick color adjustments and evaluating studio lighting conditions.  The ColorChecker Three-Step Grayscale is a full-sized version of the white, 18% gray, and black reference squares used in the 24-patch ColorChecker, all on a single card.  Use it to capture accurate color before your photo session, and save yourself editing time and effort afterward.  On site, use it as the first reference shot in a series to instantly correct image color by balancing on the mid-tone gray value. In the studio, use it to evaluate exposure and balance between main and fill lights to quickly set up the proper lighting ratio, and to set white balance.  The ColorChecker Three-Step Grayscale target also provides reference values for adjusting colors within most common photo processing software packages, allowing you to make quick color adjustments.  The ColorChecker Three-Step Grayscale is scientifically engineered to provide a precise, uniform surface that is spectrally neutral (reflects equal amounts of red, blue and green) in all types of lighting conditions.  Use it for a variety of applications: Digital Photography: Check images, set white balance and verify exposure and balance between main and fill lights; Traditional Photography: Check films, lights, filters and paper; Cinematography (Television and Video): Check cameras, lights and film.