I am displaying my ignorance here for all to see, but I am searching for the type or name of a filter which came with a OM kit I have recently bought, it seems to have 5 different prisms (right word?) within the lens, I can see what it is trying to do, 5 different scenes within the image. Can anybody tell me what style of lens this is, thus I can search and learn how to use, it is the type of filter they must have used for those old Led Zeppelin clips back in the seventies if you know what I mean. It is a IZUMAR filter 58m size and fits my OM-2, there is no model name on this filter. Thank you in advance for your advice I feel such a numpty that I can find this on Google and I have indeed tried rather than waste your time.