LenticularBlog.com

Different “pitches”

Mechanical pitch: The exact physical count of lenticules per inch. Pitch value is measured in Lenticules Per Inch (LPI).

Visual pitch: the distance at which we have the best visual result.

Prototype pitch: determined from the visual pitch, is the pitch in which we must interlace the document to acquire an appropriate prototype.

Printing press pitch: determined from the visual pitch, is the pitch in which we must interlace the document to acquire an appropriate final print.

Why different pitches?

Mechanical pitch: for exemple, a 75 LPI lens is not exactly composed of 75 lenses by inch. The pitch is more of 75.52. So, it is composed exatly of 75.52 lenses by inch.

Prototype pitch vs. printing press pitch: The lens strips are round and on a 20″ X 28″ lens format it is impossible at a short distance to visualise the center of each strips (necessary data for interlacing). We use a linear sample, a “pitch tester”. With this tool we determine at which resolution the pitch is locate for a maximum visual effect.

WHy do we have different pitches for the prototype and for the final print ?

The prototype is an ink jet print laminated manually on a lens. The final print is printed directly on the lens. These 2 kinds of print are diffrent in many ways (paper/plastic lens, resolution…) So for all different kind of printing, there’s a different pitch.

This entry was posted on Friday, June 27th, 2008 @ 12:31 pm on the category Uncategorized. You can follow any responses to this entry through the RSS 2.0 You can leave a response, or trackback from your own site.