The instructions in the DI-13 box are old and based on the old 100 - T-max. My suggestion would be to do a film test. It does work best with 100 T-Max and Phil has suggested not to do a pre-soak for best results. For information on the BTZS film testing procedure please see the instructional videos on youtube. To find them just do a search on the word "viewcamerastore". Also you can email or call me for more information.