guys i ben reading a lot about zone system now i want to practice it. the problem is i am using 35mm slr . u know rest of the story. this months pp magazines shows that ilford fp4 plus has a great latitude of -1 2/3 / +1 2/3 witch i think makes it the best roll film for pull and push process hence achief the zone required. quistion is, is what i am thinking is correct if so then can anybody tell me what is the actuall film speed for ilford fp4 plus and what is the time increasment or decreasment for n-1 n-2 n+1 N+2 when developed in ilford ID-11 this is the only developer we have in bahrain what a petty.!! thanx

-- hamad sharif (hamadshairf@hotmail.com), September 28, 1999

Answers

With 35 and 120 roll film you cannot do +/- development unless you have interchangable backs, I don't know of any 35 which has that. Have you preformed your Personl Exposure Index test, and your Zone VIII development test, if you have not, then there is no point in discussing this, and if you have you would know the above already, you must do the tests yourself, no one can give you their times, it will not work for you, it must be geared to your equipment and development techniques. Pat

-- pat j. krentz (krentz@cci-29palms.com), September 28, 1999.

Sorry Pat, but you can too do expansions and contractions on 35mm and 120 film. The problem, though, is that you do it to the whole roll.

Hamad, the best thing for you to do is to get a copy of Davis' Beyond The Zone System. This book will tell you everything you ever wanted about how to determine your true film speed, processing times for expansion and contraction, etc. The problm is that what works in my hands may not work exactly the same way in your hands because in using the Zone System you are calibrating your whole system. Differences in the sensitivity of your meter versus mine, differences in the accuracy of your shutter times versus mine, differences in temperature control between your darkroom and mine etc all effect your final speed rating, development times and contrast indeces. You really have to figure it all out for yourself. Get a copy of BTZS and you will be able to work it all out for yourself.

As far as ID11, that is a perfectly good general purpose developer. In fact virtually all films are designed to work well with D-76 which is essentially identical to ID11 (they used to be identical but I think that Ilford has tweaked the ID11 formula, but not in ways that effect its properties).

Learning the Zone System, even if you dont use it per say, is a very useful exercise. You learn much along the way about exposure, film response, development, visualising the scene, determining your desired image, etc. Charge ahead.

-- Fritz M. Brown (brownf@idhw.state.id.us), September 28, 1999.

The above advice is all good; if you want a starting point for experimentation, add 10-15% to increase contrast n+1; double it for n+2. Decrease by the same percent for n-x.

My experience with sheet film is that you should be able to get N+/-2 with FP4+ and N+3/-2 with HP5+

-- John Lehman (ffjal@uaf.edu), September 30, 1999.