This is a really stupid question, but I keep confusing myself. Ok so I have 500ml of Rodinal and if I want to mix 1:100 my final mix is say 300ml do I divide 300 / 101 = 2.97 So I need 2.97ml Rodinal and 297ml water. So does that really mean that I will get out of that 500ml 168 rolls of film? That seems like loads. I just need to double check as this saturday will be my first time developing, I might do 1:50 anyway as measuring 3ml might be hard.