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Set units of measurement

With this function you can set and change all the units of measurement being used. When you click on the icon, the following dialog box will appear:

Normally, you will use the fields for pre-defined measurement units on the right side of the dialog box. This is first of all the Base measure, which is the unit that Calamus uses internally for computation. You may choose between 1/10 æm (1/10 of a micrometre or 100 nanometres!) or mpt which are milli-pica points (1/72,000 of an inch or around 353 nanometres). In principle it does not matter much which unit you choose here. To prevent round-off errors in character and frame calculations, however, you should choose the unit that you use most often for working with Calamus. So if you measure pages, characters and lines in centimetres or millimetres but Calamus is working internally with milli-pica points, round-off errors may occur.

The measurement unit for Page measure can be set to cm (centimetre), cic (cicero), inch or pica by clicking on the appropriate button. This choice will affect the Coordinate display (at right of the Top row) and the layout rulers which you can display on screen around the document (to be described later). This unit of measurement is also used for various guidelines. If you are new to DTP, you will probably want to work in inches or centimeters. For more advanced work, picas (1/6 " or around 4.23 mm) allow greater precision. The cicero (4.5 mm) is used mainly by professionals in Continental Europe, including Germany.

The table compares the different units of measure:

The font measure unit is specified in the next line. This applies for example not only for the font size, but also word, line, and paragraph spacing as well as underline thickness and offset. English speaking users will normally use points pica (pt) for these measurements, while Central Europeans usually use millimetres (mm) or points cicero (p).

The last selection will set the measurement units for lines and raster areas. This selection is separate from the text measurement unit for good reasons. In professional layout, font sizes will usually be given in points pica (pt) or cicero, while various page elements like lines and rasters will use inch or millimetre measurements.

Because for text setting it is often desired to use a unit of measure for text rulers, kerning and frame anchors that differs from that used for the font size, there are three popup menus for these items at the bottom where you can choose which of the four previously defined measure units should be used for each.

For very special applications, experienced DTP professionals can select a base unit of measurement suiting their requirements, and enter the name of this unit into the field supplied. In the next two fields enter the values for this basic unit as a fraction of a millimetre. Thus the unit "1/10 æm" corresponds to 1/10,000 mm, and "1 mpt" corresponds to 254/720,000 mm. Any other units must be given as vulgar fractions of the base measurement unit.

All units of measurement can also be altered while working with Calamus without affecting the document being edited.

Tip: If during working you find that the measurements you input strangely alter slightly, then the cause could be that you are working with an unfavourable base unit size. For instance, if you use mpt as the basic unit, you can expect round-off errors if you input any dimensions in mm. In case of doubt, always select the smallest possible base unit size that Calamus offers: 1/10 micrometer.