In the latest tips article to be added to the site, I explain How to Calculate Lens Working Distance
While this distance is easy to calculate with a tape measure or other distance measurement tool, you can also use the site's Lens Specifications and Measurements
tool to obtain this information without leaving your seat.
Those having read the yesterday-posted Sigma 105mm f/2.8 EX DG OS HSM Macro Lens Review
will recognize the discussed formula.