The Chart Tab

Film Charts

Select the “Chart” tab and you’ll see a chart in the left pane of the window and a list of 6 charts in the information panel at the right. The name of the chart being displayed is highlighted. The charts are: Dev. Time/SBR; Dev. Time/G; Dev. Time/N; EFS/SBR; EFS/G; and EFS/N. The EFS charts demonstrate the effect of development variations on effective film speed; the Dev. Time charts relate developing time to subject range as it may be expressed in stops, as calculated from curve gradient and film DR, or as represented in the Zone System as an “N-number.”

Although these “Dev.” and “EFS” charts are calibrated and proportioned differently in the screen display, the individual charts in each group provide the same information, so you can refer to any one of them for working data.

The information panel offers you the same options that were available in the “Analyze” tab window: The “Paper ES” field will contain the default value of 1.0 unless you’ve changed it; the “Flare Density” and “Exp. Adj.” fields are empty by default but will contain any values you’ve entered previously.

The final field, “Zone Spread,” refers to the difference between the Zones you’ve chosen to meter. For example, if you’ve “placed” your low luminance value in Zone III and are checking to see how the high value relates to Zone VII, the Zone spread is 4 (3 from 7). The Zone spread field is enabled only when one of the N charts is being displayed.

You can change any of these values and watch the effects immediately as the program recalculates the chart coordinates.

Tracking Dev. Time

The “Track” tool is enabled when one of the Dev. Time charts is showing. Select it and you can run the mouse cursor along the curve for an instant readout of developing time for any value of subject range (or G-bar, or N) that interests you. This information also appears in the Status Bar at the bottom of the screen. This “Track” feature is not enabled when the EFS charts are displayed.


Paper Charts

The information panel in the paper “Chart” tab window offers you two choices: ”ISO Range Chart” and “Paper Grade Chart.” The Paper Grade Chart plots paper ES values against grade or filter numbers. The ISO Range Chart multiplies the ES values by 100 then rounds them off to the nearest multiple of 10, in accordance with industry practice.

By default the data points in these charts are connected to make it easy to estimate intermediate values but in some cases you may prefer to have one or more of these points standing alone. Typically, when testing a variable-contrast (VC) paper, the first curve will represent a “no filter” exposure and it serves no useful purpose to have that data point connected to any of the filter data points. You can control the connection by checking or unchecking the “Don’t connect in chart” box in the “Curve Details” dialog box that’s available from a button in the “Data” tab window. If the box is checked, that curve data point will not be connected to the others in the chart displays.

The Paper Grade chart combines both ES and conventional paper grade values; ES values on the right, and grade numbers on the left, making it easy to relate the ES values to the older grade categories.