HCT User Guide
page 5
Copyright © 2001 HutchColor, LLC
User_Guide_43.docx 2/10/19
Reflection:
5x7 inch Fuji Crystal Archive paper.
Kodak Ultra Endura.
Transmission:
4x5 inch Ektachrome™ and Fujichrome™.
6x7cm (2-1/4 x 2-3/4 inch) Ektachrome and Fujichrome.
35mm Ektachrome and Fujichrome.
NOTE
: 35mm and 6x7 cm targets are cut to size from 8x10 inch sheet film and are not created on
actual 35mm or 120 film, however because similar dyes are used in all product sizes, they produce
equivalent results.
Choosing an emulsion:
Either Fujichrome or Ektachrome HCT targets seem to reproduce Agfachrome™, Ektachrome and
Kodachrome originals quite well on Heidelberg (Hell) 3000-series and Fuji (Crosfield) Drum scanners.
Other scanners like the ICG drum scanner and most CCD desktop scanners require custom
Ektachrome or Fujichrome profiles for optimum color matching. If only one emulsion is chosen for
general use, pick the film type you scan most often.
Differences from IT8.7/1 and 2 scanner targets
•
The IT8 was designed in the 1980s as a visual scanning guide, then adopted for scanner
profiling with no change. The HCT was designed specifically for scanner profiling.
•
With over 500 discrete patches the HCT contains around twice as many samples as the IT8’s
252 (Kodak) or 288 (Fuji and Agfa) patches.
•
All HCT targets (except 35mm) are individually measured for highest accuracy. 35mm targets
are produced in very small batches on a sheet of 8 x 10 inch film. Two 6x7 cm targets on the
same sheet are measurement and averaged to produce an extremely accurate “batch-
averaged” data file for the whole sheet.
•
The HCT specification does not define colorimetric values for any patch, but allows the widest
dynamic range and color gamut possible with the base material. HCT colorimetric values are
proportional to, and distributed more evenly throughout, the media’s available color space.
•
Special emphasis is given to very dark patches, colored and neutral, so the HCT can better
characterize deep shadow details, which are virtually ignored by the IT8.
•
Special manufacturing gives the HCT a wide density range that better represents the dynamic
range of live originals. This means there is less chance that an HCT profile will ‘clip’ or ‘plug’
important detail in over- or under-exposed areas.
•
A 63-step gray scale improves the analysis of non-linear scanner performance, especially in very
light and dark tones – especially important with older or badly-calibrated scanners.
•
The gray scale contains 21 “nominally neutral” patches plus 42 “not-quite-gray” patches (absent
from the IT8) with subtle red, green, blue, cyan, magenta and yellow color biases, to more
accurately characterize a device’s near-neutral performance.
•
Twelve scales of fully saturated color extending from white through maximum saturation to
black, replace the six scales in the IT8 which extend only from white to maximum saturation.