水下变焦镜头的设计

通过对光在水中传播特性的分析，讨论水下摄影中需要特殊考虑的关键因素，如光能衰减、镜头视场损失和内腔防水等，分析普通相机加隔水窗后在水中拍摄时像质变差的规律。为了适应深水探测，获得清晰成像质量，基于光焦度分配公式，提出了水下变焦镜头设计思想。用实例说明水下镜头的设计方法，设计的镜头相对孔径为F/1.6。设计结果表明：该镜头克服了普通镜头水下使用像质变差和最大视场渐晕等缺点。

Design of underwater zoom lens

Based on the analysis for propagation characteristics of the light traveling in water, several essential factors in underwater photography, such as energy attenuation, field loss and water proof, are discussed. The regularity of image quality degradation due to defocus was analyzed when ordinary cameras installed with water proof windows were used under water. To achieve high quality images in deep water exploration, the design concept of the underwater zoom lens is proposed based on the focal power division formula, and an example is given for further explanation of the design consideration. The relative aperture of the zoom lens is F/1.6 in this design. The image quality of the zoom lens is improved, and the maximum FOV vignette is avoided.