Contraction is taking a wide range of light levels ("a lot of zones") and conracting (not concentrating) them down to fit on the film by a combination of increased exposure and reduced development. See any zone system text (e.g. The Negative by Ansel Adams) for details.(posted 8710 days ago)Most modern 35mm films will be OK with N-1 (a 1 stop conraction), some might just make it to N-2 (a 2 stop contraction).