The current filter wheel has J, H, H+ND, K', K'+ND and a blocker; where
ND = 5% neutral density filters. Please rotate the wheel CLOCKWISE,
It appears that selecting different filters does not have a strong effect
on the positions of the beams on the nicmos. However, to be cautious, I
usually double check from time to time that this is really the case.
to Instrument Subsystems Page