Sekonic SR-1800 Operating Manual page 49

SR-1800
(5) Colors that can be used as dropout colors differ depending on the model, but with some
models, even regular ballpoint pen ink drops out and cannot be used. In such cases, you need
special OCR ballpoint pens that are rarely available today. See table below for relationships
between wavelengths and colors.
Peak sensitivity wavelength
740(nm)
660
570
530
a) It is important to control the PCS value to print dropout colors. (You need to choose a
printer equipped with devices that can measure PCS values.)
b) If you want to use an abundance of colors, we recommend printing in ink other than
dropout colors as a "black frame sheet."
No feed
Refers to the sheet doesn't get fed during sheet feeding operations.
If such an error occurs, the device assesses it as a sheet feeding error, and notifies user of the
error.
PCS (printed contrast signal)
Refers to the reflectance ratio (contrast) of printed marks, symbols, and letters as opposed to
reflectance of non-printed areas. The calculation formula is as follows.
PCS = White reflectance - black reflectance PCS = White reflectance - black reflectance
White reflectance White reflectance
When reflectance of areas with no printing is 70%, and reflectance of printed marks, symbols,
and letters is 10%, the PCS will be 0.857.

Color
Sepia
Magenta
Purple
Abundant dropout colors
Brown
Some ballpoint pens cannot be used.
Bluish tones
Greenish tones
Rose
Pink For red end colors only, rose aniline, purplish red, deep red
Red Regular ballpoint pens can be used.
Orange
As in fax scanners, it's difficult
to see with human eyes → should be avoided.
Yellow
Regular ballpoint pens can be used.
Blue
Regular ballpoint pens can be used for blue-end colors
only. Green
Green
Remarks