OSU Interference Filter Set (2015Aug13)
60 mm square interference filters permanently mounted in cells for the 12-position Buckeye filter wheels with direct imaging cameras or in the OSMOS filter wheels.
Note that when using the filters in OSMOS the bandpasses will blueshift and slightly broaden from what is listed below because the filter wheels are tilted by 8ยบ.
All wavelengths below are in nanometers. Click on the individual filterID numbers for transmission curves.
CenLam = central wavelength
W50 = full width at 50% peak transmission
W90 = full width at 90% peak transmission
Red-Shifted H-alpha Filters:
FilterID
CenLam
W50
W90
Defects
2.7
661.4
4.0
outer 2mm border low
666.3
3.9
2.5
measles at the periphery
3.8
671.4
5.2
no defects
676.3
4.2
2.6
outer 2mm border low
2.7
680.9
4.2
no defects
Red-Shifted [OIII] 5007 Filters:
FilterID
CenLam
W50
W90
Defects
1.2
503.7
3.0
outer 4mm border low
507.1
2.9
1.2
outer 5mm border low
1.5
509.6
2.9
outer 3mm border low
512.8
2.9
1.4
outer 3mm border low
1.5
515.7nb3
515.9
2.9
no defects
2.0
520.0
3.5
outer 3mm border low
Nebular Filters:
Line
CenLam
W50
W90
Defects
2.5
H-alpha
656.8
4.0
outer 4mm border low
H-beta
486.5
2.7
1.5
outer 8mm border low
1.5
[OIII]
501.0
2.9
measels central 38mm
[NII]
575.5
2.6
1.6
transmission degraded
2.2
630.2
3.1
outer 4mm border low
1.7
HeII
468.7
3.3
no defects
1.2
436.4
2.85
no defects
1.2
H-gamma
433.6
2.8
no defects
FilterID
[OI]
[OIII]