Fixed focal length lenses from the UAV ...
series
The Cx series lenses feature an easy accessible middle section, which allows simple integration of filters, liquid lenses, or powered irises: using filters within the lens both improves performance while reducing cost due to smaller filter size. The use of liquid lenses, mostly limited due to small clear apertures, is easily facilitated and grants higher performance as compared to positioning it at the front or rear of a fixed focal length lens. The integration of powered irises enables control of depth of field and light throughput in applications with varying lighting conditions.