Similarly, if it is dusty or there are a lot of other larger particles in the air, this will filter out larger wavelengths, resulting in a red sky and red sun.
同样，如果空气中尘埃比较多，或是空气中有很多其它大颗粒，那么那些较长的光波就会被过滤掉，于是天空就会是红色，太阳也会是红色。
A graduated neutral density filter will also help you make sure the sky isn't overexposed.
累进中性密度滤镜将保证你照片里的天空不会曝光过度。
The principle, the system concept and the choice of lamp, spectrum, filter of the night sky radiation simulator for the performance evaluation of lowlevellight night vision systems is introduced.
介绍用于微光夜视仪性能评价的夜天光模拟器的原理和系统概念以及对光源、光谱、滤光片等的选择。
应用推荐