In order to enhance the visual effect of an evening sky or the horizon of a Seepanoramas this inexpensive Verlauffilterset is very well suited. They consist of three screw filters, blue, gray and orange. and they are on the front of the lens screwed .There are filters made of resin and the screw sockets are made of plastic should .MAN handle it carefully because the fine thread can be easily damaged when screwing on the lens !!. , The filters themselves are sensitive .. ... you are in transit but (together) secured with a front and end cap .. they are but for this price useful and give good results !!. They are available in almost all lens diameters .Damit are the camera's internal filter is no longer absolutely necessary, and the subsequent processing in the image processing program may also be omitted .man should always make test shots.! The use in co-rotating lenses is a bit difficult .. because there are half notched colored filter ... You always have the gradient horizontally for image stehen.Schnelle delivery Amazon and solid packaging, therefore from me four Sterne..Nachtrag. (The filter lift very well out the clouds and moods .... see my set test images)