The directions worked. The camera film cassette used isin Agfa Isopan F DIN 17/10 Feinkorn Kleinkorn Klienbildfilm Made in Germany This is a reuable cassette that had been cut to fit a standard 35mm cassette. It contained a cassette or 200 ASA Target film. Now that I can flip up the metal film holderup, I was able to check it at all speeds. Seems to work well.