Material Reflective Material
Overall Size 3.0 in. x 4.04 in. - 76.2mm x 102.7mm
Active Image Area 1.57 in. x 3.54 in. - 40mm x 90mm
Number of Steps 36
Step Size 10mm x 10mm
Density Range 0.10 to 1.6
with NIST Traceability No
  x $180.00

The ST-50 gray scale chart is a reflection object on semi-matte photographic paper. It is available either calibrated or uncalibrated. The four corner patches for the calibrated scales are within 0.02 density of each other. Each area is 10mm square.