The scale of a tilted photograph of focal length f taken from an altitude H, along the plate parallel through principal point is

A. $$\frac{{\text{f}}}{{{\text{H}}\sec \theta }}$$

B. $$\frac{{{\text{f}}\sec \theta }}{{\text{H}}}$$

C. $$\frac{{\text{f}}}{{\text{H}}}$$

D. $$\frac{{\text{f}}}{{{\text{H}}\cos \frac{1}{2}\theta }}$$

Answer: Option A