Tool for visual inspection
Test report by Eddy Senn, P/B/U Beratungs AG, on Visual Print Reference and the Altona Test Suite.
a print or proof environment. As the colorimetric evaluation in the
Generally, the software generates bare figures, which users usually
are overwhelmed and can also be misguided, the
visual inspection provides an immediate, albeit subjective, statement of the
playback quality. A test form can be used to measure and analyze the
densitometric evaluation of the tone value increase and the colorimetric
Evaluation of the integrated wedge plus a visual interpretation
qualitatively well-founded statements about the existing quality
become. This makes it possible to optimize processes in a targeted manner.
reach.
WW: For which user group was the Visual Print Reference (VPR) developed?
The VPR is interesting for users who want to print proofs and printed matter under
standardized conditions and not only measure them
or by determining the tone value increase, but the proofs and
prints visually as well. Among the
customers are print shops, prepress companies and agencies.
WW: If
apart from the subjects used, the two types of
Test forms Altona Testsuite (ATS) and VPR. Where they differ
after all? Senn:
In contrast to the widely used Altona test suite, the Visual
Print Reference does not contain any rip-sensitive elements; a rip assessment is
therefore not possible to the same extent as with the ATS. On the other hand
the VPR through the images it contains.
WW: What exactly are the advantages here?Senn:
The images used for a qualitative assessment on the ATS
are relatively small and arranged in a compact form. This makes
thus their qualitative assessment. Due to the mutual
influence, the subjects on the VPR are therefore large and topic-related
illustrated. The arrangement of the images also allows quick
Visual check of the reproduction quality in the proof used or
on the printed sheet.
WW: How great is the demand for the VPR test form?Senn:
Demand is encouragingly high; more than 120 VPR packages have been delivered to date.
WW: How do you explain the great interest?
The need for test forms such as the VPR is explained by the fact that
companies are increasingly standardizing their production, the structure and
Development of own test forms but a lot of time and know-how
require. Due to the widespread use of test forms, there are also
Cross-comparisons and quality assessments
possible immediately.
WW: Which test form should a user choose, which is the "right" test form?
According to my practical experience, the use of both test forms
make sense, as they complement each other perfectly. Unfortunately, in practice the
test forms are often equal in their functionality, which proves that
clearly still needs to be clarified here; after all, we are pursuing
The two test forms have different objectives. The
Rip functionality is better tested with the Altona test suite, for which
Checking the reproduction quality of proofs and prints in the ISO standard
however, the Visual Print Reference is more suitable.
WW: What is included in the VPR packages available for commercial and newspaper printing?
In the package designed for commercial printing, the basic data in the
PDF/X-plus format in CMYK for three paper qualities (ISOcoated,
ISOuncoated and ISOwebcoated) and in RGB (in ECI_RGB_v1).
In addition to settings for Adobe Photoshop and the associated ISO ICC profiles
are a detailed manual as well as a manual in compliance with the
reference prints produced to the relevant ISO standards.
The version for newspaper printing differs above all by
the structure of the pages in broadsheet and tabloid format and the
Photoshop settings.
WW: What requirements must be met in order to assess the visual print reference test form?
colors, is all too often undervalued. The light source
decisive influence on the color rendering. The qualitative
The test form should therefore always be assessed under standard light (5000°
Kelvin). Color indicators also help the user
determine whether an assessment of colors under suitable
conditions. These are therefore an ideal
Tools for making initial assessments
can.
Interview: Jürgen Franck
