In the geometric optics approximation, an image formed by an objective lens replicates the distribution of intensity at the front focal plane of the objective. Although this fact represents a fundamental optical principle, its application to analysis of bright-field microscopic images was developed only recently and has not been tested experimentally. In this paper, we applied simple ray tracing to compute an image of a glass cylinder at various positions of the objective and to compare it to the experiment. We obtained a close match between theory and observation, except for a slight underestimation of the intensity in the middle part of the cylinder. The likely reason for this minor difference was constructive interference due to lens-like properties of a cylinder, which could not be accounted for by geometric approximation. We expect that such artifacts would be negligible in imaging of live cells, and the geometric approach would successfully complement the existing quantitative phase methods. This article is protected by copyright. All rights reserved.

中文翻译：

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明场显微成像几何模型的实验测试

在几何光学近似中，由物镜形成的图像复制了物镜前焦平面处的强度分布。虽然这一事实代表了一个基本的光学原理，但它在明​​场显微图像分析中的应用是最近才开发出来的，还没有经过实验测试。在本文中，我们应用简单的光线追踪来计算物镜不同位置的玻璃圆柱体图像，并将其与实验进行比较。我们获得了理论和观察结果的密切匹配，只是略微低估了圆柱体中部的强度。这种微小差异的可能原因是由于圆柱体的透镜状特性造成的相长干涉，几何近似无法解释这一点。我们预计这种伪影在活细胞成像中可以忽略不计，几何方法将成功补充现有的定量相位方法。本文受版权保护。版权所有。