Filter assembly and method of manufacturing same

A method of manufacturing a filter assembly comprising at least two planar optical filters including a first optical filter and a second optical filter, the method comprising:

• providing a frame-shaped base part for accommodating the first and second optical filters, wherein the frame-shaped base part comprises a planar support part for supporting edge portions of lower surfaces of the first and second optical filters, and a wall part for laterally enclosing at least part of the first and second optical filters;
• inserting the first and second optical filters into the frame-shaped base part;
• providing a frame-shaped clamp part releasably fixable to the frame- shaped base part for securing the first and second optical filters against the frame-shaped base part, by contacting upper surfaces of the first and second optical filters and pressing the first and second optical filters towards the support part;
• and
• fastening the frame-shaped clamp part to the frame-shaped base part, wherein:
• the frame-shaped clamp part comprises a first pressing portion for pressing the first optical filter towards the support part and a second pressing portion for pressing the second optical filter towards the support part;
• and
• the first and second pressing portions of the frame-shaped clamp part are offset from each other in a direction perpendicular to the upper or lower surfaces of the first and second optical filters so as to allow the frame-shaped clamp part for accommodating different thicknesses of the first and second optical filters.