Olen tehnyt tuollaisen Cokin-X koon suodinpitimen Tokina 16-28/2,8 linssiin. Ebaysta löytyy halvat osat, joten vain suotimet tulevat hintoihinsa. Tosin ebaysta löytyy myös kohtuuhintaisia filttereitä. Itse olen tilannut Lee-suotimia Robert White-liikkeestä. Haidalla on isojakin (yli 100mm) pyöreitä suotimia kohtuuhintaan ebayssa. Suunnittelin tilaavani 150 millisen ja leikkaan siitä pari senttiä pois. http://www.ebay.com/sch/i.html?_from=R4 ... x&_sacat=0
This filter holder is made for Tokina 16-28 lens but the same construction technique is probably usable for other lenses too. I shoot with 5Dmk2.
From Ebay I've bought cheap Chinese Cokin X holder and 95mm ring which is only 2mm bigger than the lens hood outer dimension. Also from Ebay Lens Coat hoodie 3.25 "which is a neoprene and tight enough for Tokina. These cost about 40-50 € in total.
Bottom of hoodie is taken out and glued to the ring with super-epoxy. I used a suitable thick roll of (scotch ) tape inside hoodie to help keep it in place until glue was dry. Helix of the ring facing towards camera.
Outside the ring I glued small pieces of metal wire as guides for lens hood grooves. So that holder is in the correct position and at just the right depth for the filter. Then it's also possible to rotate the holder and use the 17mm wide-angle lens.16mm is vignetting slightly. Two filters can be used when the holder is pulled out a little, about 20mm is good and no longer vignetting.
The mount is really nice and tight enough to keep the holder closed and in the correct position.