Tag Archive: adjustable objective

Derivation of Riflescope Parallax Equation

Derivation of Riflescope Parallax Equation Workbook

Click the link below to open/download an Excel (xlsx) workbook that allows you to enter your scope’s values and visually observe on a graph the amount of parallax errors which might be incurred.  The workbook and calculations are derived from the article/post:  “Derivation of Riflescope Parallax Equation” by Michael G. Tappy, December 30, 2008 (Revision 1: 14 Jan. 2009).  The article is posted at the forum on rimfirecentral.com.

Link to open/download the workbook:  Derivation of Riflescope Parallax Equation.xlsx

Note:  The workbook does assume you have either read the article or have a basic understanding of parallax errors.