I am looking for a lens for a DX DSLR camera either Canon or Nikon to videotape an orthodontics veneers procedure. Need something sharp for extreme closeups from a distance of about 4 feet. What's your recommendations?
A 100mm macro will give you about 16" horizontal field of view at 4 feet on a full frame (ca. 36mm) sensor, so you could extrapolate from there for your specific sensor. If you needed a tighter fov you might choose a longer focal length and supplement with an extension tube as required. I recall this being asked in the past so there might be some more info in the archives. As focal length and length of tubes increases so does your light requirement.
