NIRCam Filters

JWST NIRCam offers 29 bandpass filters in the short wavelength (0.6–2.3 μm) and long wavelength (2.4–5.0 μm) channels.

On this page

Each of the 2 NIRCam modules carries a nearly identical set of 29 filters. Most filters are located in the filter wheel and are used in combination with pupil wheel elements including CLEAR, grisms, coronagraph Lyot stops, and weak lenses.

The 6 filters located in the pupil wheels (F162M, F164N, F323N, F405N, F466N, and F470N) include their individual pupil aperture stops and are used in combination with a second filter in the filter wheel (F150W2, F322W2, or F444W) because the filter wheels contain no CLEAR elements.

 


Filter transmissions

Filter transmissions (including all system throughputs) are plotted in Figures 1 and 2; ASCII tables are also provided.

Throughputs vary somewhat between the detectors due to differences in detector quantum efficiencies. Total throughputs are shown in Figures 1 and 2. Figure 1 shows the throughput averaged over all detectors, while Figure 2 shows the throughputs for each detector separately, as well as averaged across all detectors.

 

Table 1.  Numbers of extra-wide, wide, medium, and narrow filters in each wavelength channel

FiltersR = λ/Δλ

Short wavelength channel
(0.6–2.3 μm)
Number of filters

Long wavelength channel
(2.4–5.0 μm)
Number of filters

All~1–921316
Extra-wide~1–211
Wide~4–553
Medium~82048
Narrow~78–9234

Figure 1. NIRCam + JWST Optical Telescope Element (OTE) filter throughputs

Total system throughput for each NIRCam filter, including contributions from the JWST Optical Telescope Element (OTE), NIRCam optical train, dichroics, filters, and detector quantum efficiency (QE). Throughput refers to photon-to-electron conversion efficiency. Averages across all detectors are plotted. The vertical gray bar marks the approximate dichroic cutoff between the short and long wavelength channels. Filters marked "P" are located in the pupil wheel, requiring transmission through a second filter in the filter wheel, either F150W2, F322W2, or F444W. In these cases, the combined transmissions are plotted. (Figure version 5.0: Nov 2, 2022)
Figure 2. NIRCam filter throughputs in all detectors

System throughput for each of the NIRCam filters shown in Figure 1 (with the same colors). In this case the throughput for each detector is shown for each filter, as a series of lines of the same color. Plots with a black outline correspond to the mean throughput across all detectors, identical to what is shown in Figure 1. (Version 5.0 data)


Filter lists

Download all JWST + NIRCam throughput curves (version 5.0: November 2022): (tar.gz) (zip)

The JWST + NIRCam throughput curves archive file contains:

  • Both data (ASCII) and plots (PDF);
  • For each filter, throughput curves for each detector as well the average across detectors;

Detector-averaged total system transmission curves for all filters are available via the links in column 1 of Tables 2 and 3.

 

Tables 2 and 3. Characteristics of mean throughputs in the short and long wavelength channels

Short wavelength channel (0.6–2.3 µm)

Filter
(module-
average)

Pivot*
λ (µm)

BW
Δλ (µm)
Effective
response
Blue§
λ-
(µm)
Red§
λ+
(µm)
Use
F070W0.7040.1280.2370.6240.781General purpose
F090W0.9010.1940.3180.7951.005General purpose
F115W1.1540.2250.3331.0131.282General purpose
F140M1.4040.1420.4341.3311.479Cool stars, H2O, CH4
F150W1.5010.3180.4761.3311.668General purpose
F162M1.6260.1680.4691.5421.713Cool Stars, off-band for H2O
F164N1.6440.0200.3851.6351.653[FeII]
F150W21.6711.2270.4891.0072.38Blocking filter for F162M, F164N, and DHS
F182M1.8450.2380.5051.7221.968Cool stars, H2O, CH4
F187N1.8740.0240.4341.8631.885Pa-alpha
F200W1.9900.4610.5251.7552.227General purpose
F210M2.0930.2050.5221.9922.201H2O, CH4
F212N2.1200.0270.4202.1092.134H2

 

Long wavelength channel (2.4–5.0 µm)

Filter
(module-
average)
Pivot*
λ (µm)
BW
Δλ (µm)
Effective
response
Blue§
λ-
(µm)
Red§
λ+
(µm)
Use
F250M2.5030.1810.3702.4122.595CH4, continuum
F277W2.7860.6720.4122.4233.132General purpose
F300M2.9960.3180.4322.8313.157Water ice
F322W23.2471.3390.4992.4324.013Background min. Primarily used w/ grisms. Blocking filter for F323N.
F323N3.2370.0380.2903.2173.255H2
F335M3.3650.3470.4803.1773.537PAH, CH4
F356W3.5630.7870.5303.1353.981General purpose
F360M3.6210.3720.5153.4263.814Brown dwarfs, planets, continuum
F405N4.0550.0460.4184.0304.076Br-alpha
F410M4.0920.4360.4993.8664.302Brown dwarfs, planets, H2O, CH4
F430M4.2800.2280.5264.1674.398CO2, N2
F444W4.4211.0240.5333.8814.982General purpose. Blocking filter for F405N, F466N, F470N.
F460M4.6240.2280.4604.5154.747CO
F466N4.6540.0540.3204.6294.681CO
F470N4.7070.0510.3164.6834.733H2
F480M4.8340.3030.4474.6624.973Brown dwarfs, planets, continuum


Table notes:

All values are based on commissioning flight data.

Linked throughput tables include the effects of the JWST OTE as well as all NIRCam optics and detector QE.

* The pivot wavelength satisfies the equation F_\lambda \lambda_{pivot}^2 = F_\nu c, relating the flux measured in wavelength versus frequency units (F_\lambda d \lambda = F_\nu d \nu). It is calculated as \lambda_{pivot} = \sqrt{\frac{\int d\lambda T \lambda}{\int d\lambda T / \lambda}}, where T is the transmission. See Tokunaga & Vacca 2005.

 Bandwidth is the integral of the normalized transmission curve: BW = \frac{\int d\lambda T}{T_{max}}. See equation 1 in appendix E of Rieke, G. H. et al. 2008

 Effective response is the mean transmission value over the wavelength range of \lambda_{pivot} \pm BW ~ / ~ 2.

§ The half power wavelengths of a passband are the wavelengths at which the transmission falls to 50% of its peak value.



References

Rieke, G. H., Blaylock, M., Decin, L., et al. 2008, AJ, 135, 2245
Absolute Physical Calibration in the Infrared

Tokunaga, A. T., & Vacca, W. D., 2005, PASP, 117, 421
The Mauna Kea Observatories Near-Infrared Filter Set. III. Isophotal Wavelengths and Absolute Calibration




Latest updates
  •  
    Updated throughputs in tables and figures using in-flight data
Originally published