I have just purchased a 50 sheet box of Efke 25 in 5x4 and would appreciate some exposure and development info. I tried the massive dev. chart and it only lists 35mm and 120 times. Is the sheet film the same? Some people recommend using the film at iso 50. I will be using either ID11 1:1 or Rodinal so some idea of times/ exposure index would be greatly appreciated.