Olympus U-BI90CT Observation Tube

The Olympus U-BI90CT is a binocular observation tube for Olympus IX series inverted microscopes, featuring an integrated centering telescope (Bertrand lens) for phase ring centering, condenser alignment, and conoscopic observation. In standard binocular heads, the operator must use a separate centering telescope or remove an eyepiece and insert a centering tool to view the objective back focal plane for phase ring alignment. The U-BI90CT eliminates this inconvenience by incorporating the centering telescope directly into the observation head — the Bertrand lens can be swung into the optical path to image the objective back focal plane for phase ring centering and condenser alignment, then swung out for normal observation, all without removing eyepieces or changing accessories. The centering telescope also enables conoscopic observation of birefringent specimens for polarized light interference figure analysis. Compatible with the full range of Olympus IX series inverted microscopes including the IX50, IX51, IX53, IX70, IX71, IX73, and IX81. This unit is in excellent, as-new condition at a significant discount from the list price.