This application approximates the length of exposure for various B&W films (and some color films) in low light situations. In low light, extra exposure is needed due to reciprocity failure (also known as the Schwarzschild effect). As such, your camera\s meter is not accurate in low light. This application approximates the proper exposure time (based upon manufacturers datasheets). A timer is now included in the application. The application warns when the user enters an exposure longer than described in manufacturer\s datasheets. Although the exposure in these instances is crudely approximated by mathematical extrapolation, it is crucial that users conduct their own exposure tests in these very long exposure situations. Current supported films: Adox CHS 25/50/100 Adox CHS 100 II Adox CMS 20 II Adox Silvermax 100 Agfa APX 100/400 Bergger Pancro 400 Fomapan 100 Fomapan 200 Fomapan 400 Fuji Acros 100 Fuji Acros II 100 Fuji Provia 100F Fuji Velvia 50 Fuji Velvia 100 Fuji Pro 160 NS Fuji Pro 400H Fuji Superia 200/400 Ilford Delta 100 Ilford Delta 400 Ilford Delta 3200 Ilford FP4 Plus 125 Ilford HP5 Plus 400 Ilford Ortho Plus 80 Ilford PanF Plus 50 Ilford SFX 200 Ilford XP2 Super 400 Kentmere Pan 100 Kentmere Pan 400 Kodak Ektar 100 Kodak Portra 160/400 Kodak TMAX 100 Kodak TMAX 400 Kodak Tri-X 320/400 Rollei IR 400 Rollei Ortho 25 Plus Rollei Retro 80S Rollei RPX 25 Rollei RPX 100 Rollei Superpan 200 Rollei RPX 400