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--- wiki:darkroom:film:film_development [2022/01/22 22:37] – created henpe
+++ wiki:darkroom:film:film_development [2022/01/31 14:03] (current) – henpe
@@ Line 3: / Line 3: @@
 ===== Dimensions =====
 Film dimensions
-^  Format  ^    Dimension    ^  Surface (per sheet/roll) ^  •   ^
+^  Format  ^  Dimension      ^  Surface (per sheet/roll) ^  •    ^      • ^
-|   135    |   24mm x 36mm   |  311 $cm^2$ (36 exp)      |  1   |
+|  135     |  24mm x 36mm    |  311 cm² (36 exp)      |  1    |  0.67  |
-|   120    |  61mm x 760mm   |       464 $cm^2$          |  1.5 |
+|  120     |  61mm x 760mm   |  464 cm²               |  1.5  |  1     |
-|   4x5    |  100mm x 125mm  |       125 $cm^2$          |  0.4 |
+|  4x5     |  100mm x 125mm  |  125 cm²               |  0.4  |  0.27  |
 ===== Rules of thumb =====
+==== Exposure Index (vs. SBR)====
 The table below suggests how to select film exposure index (relative to box-speed) and adapt film development time (relative to datasheet) given an expected subject brightness range (SBR).[(biblio:Lambrecht2011)]
-^  SBR	^    EI    ^  Time  ^
+^  SBR  ^  EI      ^  Time  ^                        ^
-|  L	|  -       |  -     |
+|  L    |  -       |  -     | rainy or foggy day     |
-|  N	|  -2/3    |  -15%  |
+|  N    |  -2/3    |  -15%  | bright but cloudy day  |
-|  H	|  -1 1/3  |  -30%  |
+|  H    |  -1 1/3  |  -30%  | bright sunny day       |
+==== Expansion / Contraction (N +/- development) ====
+In general, a rule of thumb is to[(biblio:Lambrecht2011)]:
+  * increase exposure by 1/3 stop whenever the SBR is increased by one zone (N-1), while decreasing development by 15%.
+  * decrease exposure by 1/3 stop whenever the SBR is decreased by one zone (N+1), while increasing development by 25%.
+From another source (?), the following reccomendation is given:
 The table below suggests how to adjust film development to accomplish N+/- development.
 ^N-1	| -15% < N-1 < -25% |