MIRI has an 18 position filter wheel (filter wheel schematic) located in the imager module. There are 10 filters for imaging, 4 filter and diaphragm combinations for the coronagraphy, 1 neutral density filter, 1 ZnS-Ge double prism for the LRS mode, 1 opaque position for darks and 1 for a lens for ground test purposes. The instrument control electronics (ICE) moves the filter wheel when commanded by the MIRI flight software (FSW). The ICE can measure the absolute position of the filter wheel before and/or after movement of the filter wheel. The ICE can move the filter wheel to the next adjacent position in either direction.
The table below lists all the MIRI filters.
| λ(μm) | Δλ(μm) | Comment | |
|---|---|---|---|
| F560W | 5.6 | 1.2 | Broad Band |
| F770W | 7.7 | 2.2 | |
| F1000W | 10 | 2 | Silicate, Broad Band |
| F1130W | 11.3 | 0.7 | PAH, Broad Band |
| F1280W | 12.8 | 2.4 | Broad Band |
| F1500W | 15 | 3 | Broad Band |
| F1800W | 18 | 3 | Silicate, Broad Band |
| F2100W | 21 | 5 | Broad Band |
| F2550W | 25.5 | 4 | Broad Band |
| F2550WR | 25.5 | 4 | Redundant Filter, Risk Reduction |
| FND | Neutral Density | For Coron. Acquis. | |
| F1065C | 10.65 | 0.53 | Phase mask, NH3, silicate |
| F1140C | 11.4 | 0.57 | Phase mask, cont. or PAH |
| F1550C | 15.5 | 0.78 | Phase mask, cont. |
| F2300C | 23 | 4.6 | Focal Plane Mask, Debris Disk |
| OPAQUE | Blackened Blank | N/A | For Darks |