Epson Stylus Pro 7900 User Report page 7

Ultrachrome HDR
In the beginning there was Ultrachrome. Ultrachrome K3 added the light light black, and K3 with Vivid Ma-
genta saw a reformulation of the magenta and light magenta inks. The Espon X900 showcases the latest
Ultrachrome variant, dubbed Ultrachrome HDR (High Dynamic Range). This new version adds an orange and
green ink to the mix. At the same time the ink set features an improved pigment encapsulation that is sup-
posed to eliminate bronzing and gloss differential. Gloss differential seems virtually nonexistent. Bronzing is
still present, although it is fairly minimal. While the HP Z3200 manages to eliminate bronzing using a clear
gloss enhancer, this increases the total amount of ink used considerably. Epson has struck a different balance
by significantly reduced bronzing, without the need for any sort of coating.
Orange and Green
The added inks are designed to expand the gamut, and this is fully
examined below. However, the added inks have other advantages.
They help to reduce ink costs since the printer can now produce
green using a single drop of green, rather than mixing yellow and
cyan. They are also help produce more uniform solid colors and
improve tints and transitions. Epson's screening on the X880
series printers was exceptional and I'm happy to report that it as
good if not better on the x900. The improved screening means that
these printers can produce very high quality results at 720x720dpi
and benefit from the speed afforded by this resolution.
Gamut Comparisons
While they don't tell the whole story, I've included several gamut
plots in this review. The plots are useful in showing the general
shape and size of the printer's gamut. Compared to the Epson
X880, the X900 shows a dramatic expansion in gamut in the
orange and green regions, exactly what you would expect from
the added orange and green inks. This advantage is most evident
in the midtones and 3/4 tones. When compared to the Z3200 it's
much harder to draw any meaningful conclusions from the three-
dimensional plots. The X900 and Z3200 excel in different areas,
and overall the differences are fairly small, although the total
gamut volume of the x900 is larger than the Z3200.
To fully evaluate the output produced by the 7900, I made a num-
ber of prints which were then printed on the Z3200 and Epson
7880. The test prints were made on both photo and matte papers
using both custom and canned profiles and different rendering
intents. The images featured both photographic imagery and test
imagery such as color ramps and rainbows. After carefully digest-
ing all of the results, I came to the profound conclusion that all of
the printers tested produced excellent results. That's not intended
as a cop out, but rather the endorsement of a belief that the aque-
ous inkjet printer has reached a level of maturity. That said, I don't
want to imply that there aren't differences between printers or objective improvements, simply that in regards
to color gamut the benefits will not be appreciated by every user. The subtle difference in the test prints were
almost completely invisible unless the images were in the ProPhoto RGB color space.
Epson 7900 Prem Luster - Color Wire Frame
HP Z3200 Pro Satin - Solid White
Top view
Epson 7900 Prem Luster- Color Wire Frame
HP Z3200 Pro Satin - Solid White
Lower view