title: Slanted edge MTF evaluation with ImageJ plugin
body: <p>I am trying to evaluate an optical system by calculating the MTF with the slanted edge method. For this I use the following ImageJ plugin:
  <a href="https://imagej.nih.gov/ij/plugins/se-mtf/index.html" rel="nofollow noreferrer">https://imagej.nih.gov/ij/plugins/se-mtf/index.html</a></p>
  <p>No I want to calculate the MTF with the frequency units &quot;lp/mm&quot;. For this I have to insert the &quot;Sensor size (mm)&quot; and the &quot;Number of photodetectors&quot;. Sadly I cannot find any description and what these values are exactly. If I use the diagonal of the sensor in mm and the number of pixels my sensor has as the second value, I get nonsense values (very high frequencies, higher than 100000 lp/mm).
  Does anyone have experience with this tool and can give me a hint on what values I need here?
  Thanks a lot in advance!</p>