When viewing extended objects, the apparent brightness seen in the eyepiece is a function only of aperture and magnification, it is not related to focal ratio.

当观察扩展光源时，目镜中所看到的亮度只跟孔径和放大率有关，它跟焦比并没有关系。

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At high magnification, the dark red thrombus is apparent in the lumen of the coronary. The yellow tan plaques of atheroma narrow this coronary significantly, and the thrombus occludes it completely.

放大后可见冠状动脉管腔内的暗红色血栓较明显，粥瘤的黄褐色斑块使得冠状动脉明显狭窄，并且血栓完全阻塞了管腔。

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