English
10
Operation
Operation
When the unit is plugged into a power source, the red OFF button (G) is illuminated.
To select a light source simply press the desired button. When a source is selected
the appropriate green button will illuminate to verify your selection. Pressing a
different source button will turn on the selected source and turn off the original
source. Turn off all sources using the OFF button. UV (B) is independently controlled
and can be used with another source or by itself. If the Home Light (E) is selected
and not switched for 15-20 minutes, the unit will turn all lamps off (this is a lamp
and energy saving feature).
Programming a Sequence
Press and hold the yellow SEQ button (A). While holding the SEQ button, press the
buttons for the sources you wish to turn on in the order you want them activated
(up to 10). After selecting your light sources, while still holding the SEQ button,
press the OFF button for the length of time you want each source to be on (note: all
sources will be turned on for the same time period - if you want an individual light
source to be on 2 or 3 times longer, simply press its button two or three times while
programming the sequence. The sequencing “On” period has been programmed
to not allow “On” times to be less than 5 seconds). After releasing the OFF button,
you can release the SEQ button. The SEQ button will stay illuminated. To use the
automatic sequence simply press the illuminated yellow SEQ button. The sequence
will remain in memory until a new program is entered, or, if you press the SEQ
button and hold while pressing the OFF button, this will also clear the sequence.
You can use the selection buttons to operate the unit normally even though a
sequence is stored.
Adjusting for Sample Brightness
For optimum viewing of color samples, dark materials require more light and light
materials less light. When viewing very dark materials, the samples should be raised
closer to the light source and moved away from the source when viewing very light
samples. As a “rule of thumb” very light materials should be placed at the bottom
of the booth, material of medium lightness should be raised approximately 13 cm (5
in) from the bottom, and very dark materials raised 25 cm (10 in) from the bottom.
This is an approximate light intensity range of 100 to 200 footcandles, covering
virtually all viewing requirements.
Detecting “Metamerism”
When two color samples match under one light source, but not under one or more
other light sources, the “color-match” is metameric. This means that the colorant
formulation in one sample differs from the formulation in the other, resulting in
differing spectral reectance factor curve shapes. A metameric color match can
also be referred to as a “conditional” color match, since the quality of the color
match is conditional to the type of light source under which it is viewed.
While it may not be possible, with the colorants available, to completely eliminate
metamerism, the byko-spectra lite provides colorists with the means of visually
“indexing” the degrees of metamerism under three spectrally dissimilar light
sources. The formulation may then be adjusted to provide the “best match” under
a specied lighting condition, or the least metameric match under all three lighting
conditions.
For obtaining the best correlation with instrumental measurements, calculated color
differences and metameric indices, the spectral power distribution of the sources in
the booth should be used in the computations.
