Point Resolution

Point Resolution (or Point-to-Point, or Directly Interpretable Resolution) of a microscope corresponds to the to the point when the CTF first crosses the k-axis at the extended scherzer defocus and can be expressed as:

Phase contrast images are directly interpretable only up to the point resolution (Scherzer resolution limit). If the information limit is beyond the point resolution limit, one needs to use image simulation software to interpret any detail beyond point resolution limit.