With an angle of 114°, the Zuiko 7–14mm approaches the limits of wide angle optics. The highly convex front lens is one of the constraints building such a lens.
It also features a built-in lens hood that doesn’t allow screw-in type filters.
I took some measurements and found out, that a filter size of 100×75mm (4×3″) may be used under certain circumstances without vignetting.
I therefore designed a filter holder that accepts Cokin X-PRO filters or similar sized filters.
My prototype is built from black plastic using SLS technology. Two o-rings provide enough friction along the thin edge of the filter to keep it in place.
I have launched the production of the holder in a small batch. This has reduced the costs per piece significantly. A large number of items have already been sold and shipped. The design allows the use of Cokin X-PRO style filters. A filter has to cover at least an area of 100×128mm and is allowed a maximum width of 130mm to fit. Filter thickness may vary between 2.5 and 3.5mm. The filter will be kept in place by two guiding rails on both sides of the frame. Up to two high quality o-rings provide additional friction if necessary.
The filter holder extends the built-in lens shade. It reduces flares caused by stray light.
Filter holders have been built with vacuum forming in a silicone mould. This technique combines die cast quality with a reasonable pricing for small batches.
The mould doesn’t allow further casting, so the filter holder isn’t available in vacuum dye-casting anymore. To provide the filter holder at reasonable costs, I decided to upload the shape to shapeways. Prints of the filter holder are built there in SLS laser sinter technology. You have to stick felt pads to the inner side of the tube to adapt the holder to your lens. This will prevent scratching of the lens barrel. You may use two rubber bands or o-rings (NBR 70, 65×1.5mm) around the guiding rails which will add friction to keep the filters in place.
You may replace the felt pads by textile adhesive tape. You may replacec the o-rings by common rubber bands,
In the video, you see the usage of the filter holder. Reinhard Wagner took the video during a trip to the island of Helgoland.
Please note, that Shapeways delivers printable parts only. It’s up to you to get the felt pads or o-rings!
Please place orders directly through my webshop at Shapeways.