Never used Adox/Efke 50 but Adox/Efke PL100 sure is grainy
I have never used the 50 speed film but do occasionally use PL100 in 4x5 (shot at and densitometer tested to be about EI 50) developed in Rodinal 1:50. The negatives and prints show great tonality but two aspects become apparent. The emmulsion sure is delicate. I have managed to scratch it even using a 4x5 daylight tank, and is certainly easy to scratch with tray development. This is also the only time ever I have seen visible grain in an 11x14 print printed full frame from a 4x5 negative. From my experience the PL-100 film has bigger/more visible grain than Ilford HP5+ or Kodak TXP 320!
Sincerely,
Hany.