ISO TS 20793:2019 pdf download.Photography – Lenticular print for changing images – Measurements of image quality.
Lenticular printing is a technology wherein lenticu tar lenses are used to produce printed images with an illusion of depth, i.e. three-dimensional (3D) effect, or the ability to change or move as the image is viewed from different angles. Lenticular prints to display changing images are built up with a lenticular lens sheet and a printed sheet that contains at least two images, interleaved with the same spacial frequency as the lenticular lens sheet.
Lenticular tenses are an array of magnifying lenses.
Widespread applications of lenticular printing are signage, display posters, business cards, multilingual message boards and packages with changing images or 3D effects.
It has been reported that the market size of lenticular prints is over 100 million m2 and that the market is growing. Furthermore, the potential image qualities of lenticular printing have dramatically improved and further improvements are expected in the future. While production of lenticular sheets with a lens frequency of 100 Ipi (tines per inch) is routine, products with a 200 Ipi frequency are also currently available.
ISO TS 20793 specifies the measurement methods and specification of image quality of lenticular prints that are used for changing images. ISO TS 20793 does not cover lenticular prints that are used for 3D images.
NOTE Lenticular prints for 3D images can be measured with the same types of procedures. However, it needs more information, such as the dependence of the measurement distance, to evaluate the 3D performance.
ISO TS 20793 specifically describes measurement methods for cross-talk, viewing angle range, angular misalignment from the designed viewing angle and the uniformity of the image within the printing area of the lenticular print images. These are critical for the image quality of lenticular prints for changing images.
ISO TS 20793 is applicable to lenticular prints produced by printing technologies that include impact and non-impact printing. Examples of the former are off-set, gravure and flexography, while the examples of the latter are silver halide, inkjet, dye diffusion thermal transfer and electrophotography. The multiple laser images (MU) and changeable laser images (CLI) process of using a laser to write through a lenticular screen at different angles to create multiple images is also used.
For standard dark room conditions, the ambient illuminance at any position on the lenticular print is below 0,3 lx in all directions or the illuminance shall at least be less than a level that does not influence the measurement results.
When directional illumination is used, standard dark room conditions shall be applied unless ttie instrumentation used is effective in suppressing background illumination.
When the sample is set in an integrated sphere, dark room may not be required.
5 Measurement conditions
5.1 General
For the measurements, the lenticular print samples shall be illuminated with hemispherical di[tuse lighting. Directional illumination can also be used when it is appropriate for simulating the use application.ISO-TS-20793-2019