分划板
英文名：Reticle
可检验分辨率和光学传递函数
分划板一般安装在望远镜的右目镜焦平面上，它是一块极簿的表面刻有分划密位线的薄玻璃，由于这块薄玻璃理论上讲也参与了成像，延长了物镜的焦距，会对右目镜的长度有或多或少的影响。分划板对洁净度要求极高，任何微小的灰尘都会在观测时产生很大的黑点，同时分划板的安装位置精度要求极高，因此，尽量不要拆卸，如果拆卸，一定要按原样复原。
Reticle
From Wikipedia, the free encyclopedia
A comparison of different reticles used in telescopic sights. The lower right represents a reticle found in the scope of a Russian SVD sniper rifle."Reticle" redirects here. For the pattern used in photolithography, see photomask.
"Crosshair" redirects here. For the fictional characters in Transformers, see Crosshairs (Transformers).
A crosshair or reticle is a shape superimposed on an image that is used for precise alignment of a device. Crosshairs are most commonly represented as intersecting lines in a "+" shape, though many variations exist, including dots, posts, circles, scales, chevrons, or a combination of each. Most commonly associated with telescopic sights for aiming firearms, crosshairs are also common in optical instruments used for astronomy and surveying, and are also popular in graphical user interfaces as a precision pointer. The crosshair was invented by Robert Hooke, and dates to the 17th century.
The word reticle is from the Latin meaning "net", a network or grid of lines displayed in an optical instrument. The minimum reticle consists of simple "cross-hairs", as described above.