To search for photos with a specific EXIF Focal Length:
  1. Click View | Search to open the Search pane.
  2. In the Search pane, scroll down to Properties.
  3. Click Add to open the Add Search Criteria dialog box.
  4. Expand EXIF.
  5. Expand Image.
  6. Click the Focal Length check box to add Focal Length as a search criterion.
  7. Click OK.
  8. In the Search pane, in Properties, click the Focal length is placeholder to open the Edit Rational dialog box.
  9. If the Focal Length is 50mm, for example, type 100 and 2 in the search panel (100/2=50). If the Focal Length is 7.1mm, for example, type 71 and 10 in the search panel (71/10=7.1).
  10. Click OK.
  11. In the Search pane, click Start.
Photos with a matching EXIF Focal Length display in the File List pane.