Magnifying Ratio and Resolution in Electronic Endoscopy Systems

Abstract

The 1990s were a boom time for magnifying colonoscopy, with a succession of reports along the lines “On examining the pit pattern with a magnifying colonoscope at 100× magnification….” However, magnification is relative, and I remember feeling a vague sense of unease at the use of the term magnification.

At the 2000 Endoscopy Forum Japan (EFJ), I asked Mr Hisao Yabe, an engineer with Olympus Medical Systems Corp., to make a presentation easily understandable by endoscopists, regarding the difference between an endoscope’s magnifying ratio and resolution. Mr Yabe was kind enough to lend me some of the slides he used in that presentation, and here I will present some extracts from his paper, along with some thoughts of my own, in a simple explanation of the difference between magnifying ratio and resolution in an electronic endoscopic system.

Definitions of magnifying ratio and resolution, and the systems of measurement and notation, vary between electronic equipment manufacturers, so this should be considered no more than a rough guide.