NOTE Filters B#8, V#9, R#10, g'#83, Clear#126 are to be used for FIES target acquisition as well.
NOTE estimated focus offset based on the thickness of the filter
The relative focus offset can be calculated knowing that it has been measured to be about 19 TCS units per mm.
NOTE, while SOFIN is mounted the red light from SOFIN makes SDSS z-filter imaging virtually impossible.
Optical filter data base