The system was later extended to cover larger ranges and some of its practical shortcomings were addressed by the Austrian scientist Josef Maria Eder (1855–1944) and Flemish-born botanist Walter Hecht (de) (1896–1960), (who, in 1919/1920, jointly developed their Eder–Hecht neutral wedge sensitometer measuring emulsion speeds in Eder–Hecht grades). Still, it remained difficult for manufactures to reliably determine film speeds, often only by comparing with competing products, so that an increasing number of modified semi-Scheiner-based systems started to spread, which no longer followed Scheiner's original procedures and thereby defeated the idea of comparability. COUNT 5
QSN1 Who developed a device that improved on the shortcomings of Scheiner's invention? ANS1 Austrian scientist Josef Maria Eder (1855–1944) and Flemish-born botanist Walter Hecht (de) QSN2 What did the Eder-Hecht device measure? ANS2 emulsion speeds QSN3 What method did manufacturers use much of the time to compare film speeds? ANS3 comparing with competing products QSN4 What type of measurement methods began to proliferate? ANS4 modified semi-Scheiner-based systems QSN5 What eliminated comparability? ANS5 modified semi-Scheiner-based systems