The American Society for Testing and Materials (ASTM) D1322 assesses the sooting tendency of fuels using smoke points. Recently, the fuel uptake rate measurement with threshold imaging (FURTI) method has improved smoke point determination. Herein, a precise and accurate detection of smoke point heights is investigated when tests are conducted with the FURTI method. First order gradients of the soot luminosity, recorded with a charge-coupled device camera, are used to detect the flame height. The analysis of several iso-octane/toluene calibration blends shows a significant diminution in the height experimental error in comparison to the ASTM D1322 standard, ranging from a minimum of 67% to a maximum of 86%. A low flame height bias, ranging from 1% to 5%, and a negligible sensitivity to the fuel sample composition is present when additional hydrocarbons are analyzed, owing to a high measuring accuracy and a robust height detection method.