We have created the new free online lens calculator that shows field of view in 3D and displays DORI zones.
https://www.jvsg.com/calculators/cctv-lens-calculator/
For additional convenience you can choose camera models from a database of camera models.
The database of camera models is the same as in IP Video System Design Tool.
You can switch the lens calculator to Imperial (Feet) or Metric (meters) mode.
Fisheye and multi-sensor cameras are not supported in the calculator.
Pixel density values for DORI zones are based on EN62676 standard. Additionally the user can load a site map.