Abstract
Microscope objectives have long been tested visually using the specimens suitable for the evaluation of their optical performance.
In this paper, we investigate the reliability of the visual testing by comparing with the testing based on the interferometric measurement of wavefront aberrations. Forty objectives were evaluated visually by four experienced observers and classified into five grades. Wavefront aberration of each objectives was also evaluated and the relation was investigated between the aberration and the visual performance. Through this investigation, following facts have been found. 1) In the visual testing, the objectives are differently classified from one observer to the other even when they are all experienced in the testing. 2) Unsymmetrical aberration should be made as small as possible, even smaller than the Rayleigh limit, in order to obtain the best performance that can be recognized by human eyes. 3) It is believed that the performance of the objectives can be evaluated objectively with the multiple bearm lens interferometer developed by us.
