Dear "analogic" friends, Yesterday I bought an Efke IR 820 for my Pentax 6x7. For infrared photos I use an 600nm filter (and not a "classic" 720nm like Hoya IR72). So, according to the datasheet I have to expose my Efke to 6 or 9 ISO. (With the 720nm filter, the recommended exposure is at 3 ISO). I like develop my film with the Kodak D-23. But... with this Efke, I haven't found information about times and/or diluitions. Please.... can you help a "young" photographer? Thanks, Enrico. P.S. Apologies for my English.