Hi Christian,
Now i want to ad the color attributes of this filter somehow to this cylinder:
I think the best way to simulate this, is to use the 'trans' material because the surface shouldn't be so shiny or polished like the glass material.
I made an Excel sheet to calculate the 'trans' parameters but it's confusing.
Why is the filter material not shiny? Does it have a rough texture that scatters light? If it is solid and transmits light, then it also reflects light. It might have a low index of refraction if it is a gel filter, similar to water with n=1.3, whose surface reflection is around 2%. You can give the index of refraction to the glass type as a fourth argument. (If you give a value of 1.0, there will be no reflection at all.)
Whether you end up using 'glass' or 'trans' as your material, be sure to leave a small gap between the surface you use for your filter and the surfaces you use for your cylinder. Otherwise, the rays will see one or the other surface at random.
-Greg