Hello everyone, In reading books, threads, different web sites I have the following questions regarding establishing EI for the various films and camera's I have. 1) How do you determe film speed since it is based on being able to develop film "in your normal way". 2) I am transitioning from PMK, normal agitation, to Pyrocat-HD with agitation cycles at 3 minute intervals. 3) Films I am testing will be: FP4 - 35mm, 120 (both in daylight tanks) FP4 - 4x5 in dip and dunk tanks Delta 3200 - 120 in daylight tanks TMY400 - 4x5, 8x10 in dip and dunk tanks, slosh trays PL100 - 8x10 in slosh trays I guess the biggest question I have is:without a "normal development time" how would you determine personal EI ?? I ball park development time in my understanding would give me the ability to read density (dont have densitometer) but wouldnt this density change if I also changed the development time also which to me would mean I would have to start all over?? I have read about using the Stouffer Step Wedge too. My question with that is how do they determine the density's on it to compare the density's of my film with ?? Wouldnt different film have different thicknesses which would effect the density's I would compare to on my film?? And lastly, once I have developed the film and determined some kind of density for film speed how would I determine if I needed to develop for longer or shorter times to get the optimum density or would I change film speed. I have read through the books The Negative by A.A, BTZS by Phil Davis and countless websites and they all (unless I missed something which is possible since my wife says I am blind) that film speed test, personal EI is conducted using your normal development techniques. Since I am changing developer and agitation which do I do first?? Use current film speed (personal EI) and get a development time and agitation cycle first, then re-do film speed test. Thanks for all the advice in advance.