title: On buying a telescope for videolaryngoscopy.
abstract: The purpose of this article is to compare aspects of the performance of three widely-used rigid laryngoscopy telescopes. The Nagashima SFT-I, Wolf 4450.57, and Karl Storz 8702 D were used with a JVC GX-N8U camera and Panasonic PV 8600 VCR to make recordings of a one-tenth-inch grid at various distances between the lens and the grid and at two telescope holding angles. Measurements were made of the anteroposterior and mediolateral viewing fields at all distances and holding angles on maximum and minimum zoom. The telescopes were compared for viewing field, lens angle effects, holding angle effects, plane distortion effects, effects due to lens distance, color, edge definition, focus control, light source compatibility, stroboscopic use, cross-sectional diameter, fogging, and cost. An overview enables laryngologists to assess their needs before buying.
mesh_terms: D006801:Humans; D020704:Laryngoscopes; D055095:Optics and Photonics; D014741:Video Recording / Q000295:instrumentation