Negative, Paper & Darkroom

This page is a collection of useful files, all concerned with the process of developing film, creating a negative and making a fine print in the darkroom. A more in-depth description of most techniques can be found in the first and second edition of 'Way Beyond Monochrome'.
Regular Densities This table includes common values for relative negative transmission and absolute print reflection densities, as well as appropriate computer monitor equivalents. Individual values may vary, but this is a good starting point to compare values.

Film Test Procedure A proper film test requires six rolls of film to be exposed, developed and graphically evaluated, precisely following a procedure outlined in the book ‘Way Beyond Monochrome’. The attached spreadsheet (supplied in .xls and .xlsx format) turns this manual evaluation into an automated numerical analysis, reducing an otherwise laborious process to the following steps and simplifying the task significantly.
Exposure Using the film’s advertised speed, fill five sheets or rolls of film with identical exposures of a transmission step tablet.
Development Develop each film for 4, 5.5, 8, 11 and 16 min and process normally.
Data Collection Measure the resulting densities and enter them into the spreadsheet.
Speed Test Fill another test film with increasing exposures before developing it normally.
Analysis Summary Enter the effective film speed and get all other exposure and processing data for your favorite film/developer combination in return. Film Development This is a table of my favorite films and their development times in Ilford ID-11 or Kodak D76 for subject brightness ranges from N-3 to N+3. The corresponding film speeds are listed in the file ‘Film Exposure’ in the ‘Camera Library’. Depending on your development equipment, materials and processes, these values may change. Consequently, they are only offered as a starting point for your own evaluations.
f/stop Timing A numerical f/stop timing table is a convenient way to determine precise printing times. It also includes dodging and burning times as small as 1/6-stop increments. It can be used with any darkroom timer, but print it large to see it clearly in the dark. Determine the base print exposure time, rendering significant print highlights to your satisfaction, and find this 'base exposure' in the center column. Base exposure times are incremented in 1 stop (black), 1/3 stop (dark grey), 1/6 stop (light grey) and 1/12 stops. After adjusting overall print contrast, rendering significant print shadows as desired, find related dodging and burning times in 1/6 stop increments left and right to the base exposure to fine-tune the final print.
Clock Dial An analog f/stop dial from 8 to 64 seconds in 1/3, 1/6 and 1/12-stop increments. You may print the dial and attach it to any analog timer.

Paper-Grade Dial With only two disks required, the Paper Grade Dial provides a quick method to calculate the overall paper contrast required to transfer the negative density range to the print density range. Using a densitometer or a simple darkroom timer, take a tonal shadow reading and set the negative density or the estimated exposure time on the dial. Then, take a tonal highlight reading, and next to its location on the dial, read off the required ISO paper grade to capture the entire tonal negative density range on paper. Note, the numbering system of variable contrast filers are only an approximation of ISO paper grades.
Paper Exposure Compensation Most manufacturers claim that their filters, or filtration values, allow for a constant exposure from grade 0 to 3, with a simple doubling of this exposure for grade 4 and 5. This is only true for the ISO 'speed point' (print density 0.6 above b+f), which is somewhere between Zone V and VI, and consequently, not very practical for pictorial photography. To obtain a consistent highlight exposure, when switching from one paper contrast to the next, an exposure compensation needs to be made. The individual exposure compensation depends on the paper, light source and color-filtration system used. It is easily determined through the following test and then recorded in a spread sheet (download the sample, and select 'cancel' if you are asked for a password). For each filter setting, create a test strip showing a highlight exposure sequence in 1/12 f/stop increments. The goal is to determine which exposure time is required to generate a Zone VIII equivalent density for each filter setting. Zone VIII has a density of 0.09 above b+f, which clearly differs from paper white but still is a very light gray (see the ‘Digital Zone Tablet’ above as a rough guide). Enter the timing results into the left column of the spread sheet, and the exposure table will be completed automatically. The value shown at the intersection of 'old' and 'new' grade shows the exposure compensation required to keep a constant highlight density for any paper contrast change in 1/12 stops. Dual-Filtration Grades Color enlargers with dichroic filters are very useful tools for B&W printing. They are typically equipped with a dichroic filter head, containing Yellow and Magenta filtration. These filters are used to alter the contrast in VC papers, and no additional investment is required. Even minute but precise contrast changes are simple. Manufacturers of enlargers and papers often include tables with Yellow and Magenta filter recommendations to approximate the paper contrast. However, these recommendations are limited, because they are based on assumptions about the light source and papers used. A custom calibration allows precise paper grade settings in accordance with ISO standards. This calibration turns the dichroic color head into a precision VC diffusion light source, ideally suited for flexible and consistent monochrome printing. The attached large dual-filtration table includes the filtration values for several papers, when using Durst (max 130M) filtration. The values of the dual-filtration table above are designed to minimize the exposure and keep it within 1/6 stop from grade 1 to 3. Nevertheless, to be more accurate, they too need an exposure adjustment when switching from one paper contrast to the next. Below are the individual dual-filtration and exposure compensation tables for several papers.
Dual-Filtration Tables
Agfa Multicontrast-RC
Ilford Multigrade IV-FB
Ilford Multigrade IV-RC
Kodak Polymax II-RC
Exposure Compensation Tables
Agfa Multicontrast-RC
Ilford Multigrade IV-FB
Ilford Multigrade IV-RC
Kodak Polymax II-RC The dual-filtration tables for the individual papers (on the left) contain the same data as the large dual-filtration table above, but they are small enough to be easily attached to your enlarger. Use the exposure compensation tables (on the right) when an exposure for a particular grade has been determined already, but a new paper contrast is required. Two tables, one for Zone VII and one for Zone VIII highlights are included.

Enlarger Height Compensation Any adjustment to the enlarger height requires a change to the print exposure. This chart provides the means to determine the exposure compensation required without calculations.
Measure the easel-to-lens distances before and after the adjustment to the enlarger. Then, find the upper 'easel-to-lens distance' on the vertical axis and the lower 'easel-to-lens distance' on the horizontal axis of the chart. The intersection of the two will indicate the exposure compensation. A previously verified exposure is increased by that compensation if the enlarger was raised and decreased if it was lowered.
The compensation can be applied either to the aperture of the enlarger lens or to the exposure time, but the use of a separate f/stop timing table may be advantageous if a modification of the exposure time is preferred. It is recommended, and more practical, to make small modifications by changing the exposure time. Larger changes, of 1 or 2 stops, are easier made by modifying the aperture of the enlarger lens. This will also keep exposure times at manageable levels.
Note, this chart does not compensate for any reciprocity failure. Paper reciprocity failure is can be estimated as being approximately 1/12 stop (5%) for each stop of exposure-time alteration. Light-Tight Drawer This is a plan to build a light-tight darkroom drawer, providing room for up to 16x20 inch paper. It should keep your favorite papers accessible and safe. I received this drawing in April of 1999, while attending John Sexton's Expressive Black and White Print Workshop in California. The file is posted here with his permission to download for your use, but not for further distribution. Please also, visit his excellent site at www.johnsexton.com to see more of his fantastic work.