
Review Summary
Some wide-angle and video zooms have a retractableactable lens assembly which means that the COKIN Filter Holder may inhibit the use of some focal lengths. To remedy this situation, use a protective screw-in filter (UV or SKY1A) and add one or several "extension rings" between the screw-in filter and the adaptor ring of the filter-holder.
Extension rings are also useful with some home video cameras which have elements obstructing the free rotation field of the filter-holder.