We hear a lot about lens sharpness; but what does it actually mean? It’s not easy to quantify but for images to appear sharp, both sharpness and contrast are involved. However, you can’t measure ...

Ronkonkoma, N.Y. — Sigma of America said Monday that it is releasing a Geometrical Modulation Transfer Function (MTF) chart and a Diffraction MTF chart for use in measuring the performance of all of ...