The maximum scale error of the Lambert Conformal Projection is what?

• A. 2 1/2 percent
• B. 1 percent
• C. 5 percent
• D. 0.5 percent

Answer: (A)

Lambert conformal conic keeps shapes locally accurate because it is conformal, so the scale is the same in all directions at a point. However, the scale factor varies with distance from the standard parallels, being true along those parallels and gradually increasing (or decreasing) away from them. In typical two-standard-parallel setups, the distortion is kept small over the mapped region, with the maximum scale error around 2.5 percent. That’s why the figure 2 1/2 percent is cited as the maximum error for this projection. The other values would imply distortions outside what this projection configuration usually yields.