Filter Summary
The following tables show the three cameras’ filters’ properties. The definitions of the columns below are those of the BANDPAR task. These definitions are summarized here. For further details please see the on-line help on BANDPAR. Here ‘INT’ refers to an integral over wavelength, and ‘THRU’ is the throughput of the filter at that wavelength. ‘LAM’ is wavelength.
Central Wavelength = bandpar.pivwv
defined as PIVWV = SQRT(INT(THRU * LAM) / INT (THRU / LAM))
Mean Wavelength = bandpar.avgwv
defined as AVGWV = INT(THRU * LAM) / INT(THRU)
Peak Wavelength = bandpar.wpeak
defined as wavelength at peak throughput (WPEAK)
FWHM = bandpar.fwhm
defined as FWHM = SQRT(8 * LOG(2)) * BANDW
Max Transmission = maximum transmission OF THE FILTER ONLY
(no other optical components) as measured pre-launch in the lab
Max Throughput = bandpar.tpeak
defined as peak bandpass throughput
The Range column describes the total range in wavelength where the filter throughput (by itself, no other optical components) is larger than 0.05%. For low-pass filters, the range is open-ended; the table lists in this case the range as the maximum range listed in the SYNPHOT/pysynphot throughput reference files.
The rightmost column, Fraction, is the fraction of light falling on the central pixel, assuming the point source PSF is centered on that pixel as estimated by Tiny Tim PSF simulations (3-gyro mode).
All data in these tables (except for the PSF-related ‘Fraction’) are generated from the STScI CDBS tables, which are updated as more accurate information is obtained. The observer is strongly advised to regenerate these tables from the most up-to-date data in CDBS if the exact values are critical to planning observations. The SYNPHOT user's guide (Bushouse, 1998) is the best guide on how to do this.
HRC Filters |
||||||||
Filter |
Central |
Mean |
Peak |
FWHM |
Range |
Trans |
Thru |
Fraction |
F475W |
4775.7 |
4794. |
5000.2 |
986.23 |
1800 |
0.913701 |
0.24735 |
0.17 |
F502N |
5022.9 |
5023. |
5005.5 |
85.867 |
145 |
0.7135654 |
0.19196 |
0.169 |
F550M |
5579.9 |
5582.4 |
5550.3 |
389.02 |
740 |
0.8770255 |
0.24687 |
0.153 |
F555W |
5356. |
5368. |
5059.8 |
841.13 |
1720 |
0.885 |
0.24037 |
0.159 |
F606W |
5888. |
5926.1 |
6689.8 |
1565.5 |
2570 |
0.9517956 |
0.27447 |
0.143 |
F625W |
6295.5 |
6309.2 |
6479.9 |
977.51 |
1720 |
0.915 |
0.26496 |
0.134 |
F658N |
6583.8 |
6584. |
6592. |
136.27 |
180 |
0.9118735 |
0.26505 |
0.128 |
F775W |
7665.1 |
7677.5 |
7320.1 |
1017.4 |
1910 |
0.947 |
0.23605 |
0.107 |
F850LP |
9145.2 |
9161.6 |
8859.5 |
1269.1 |
>3080 |
0.976 |
0.13813 |
0.086 |
F892N |
8916.1 |
8916.4 |
8915.4 |
237.98 |
320 |
0.9182586 |
0.13461 |
0.091 |
F220W |
2255.4 |
2264.4 |
2219.9 |
441.03 |
1350 |
0.361 |
0.050401 |
0.175 |
F250W |
2715.9 |
2727.4 |
2520.1 |
563.76 |
1980 |
0.48071 |
0.061124 |
0.166 |
F330W |
3362.7 |
3367.2 |
3460.3 |
409.16 |
790 |
0.751 |
0.10714 |
0.156 |
F344N |
3433.7 |
3433.8 |
3430.2 |
64.922 |
95 |
0.67994 |
0.10093 |
0.156 |
F435W |
4311. |
4322. |
4760.1 |
728.95 |
8780 |
0.92799 |
0.22602 |
0.17 |
F660N |
6599.1 |
6599.3 |
6595.4 |
175.72 |
100 |
0.7178267 |
0.20719 |
0.128 |
F814W |
8115.3 |
8146.9 |
7459.5 |
1656.6 |
2870 |
0.991 |
0.23965 |
0.099 |
POL_UV |
6231.7 |
6607. |
7399.7 |
4943.9 |
>18000 |
1.0 |
0.088816 |
0.135 |
POL_V |
6943.2 |
7184. |
9206.6 |
4134.8 |
>16500 |
1.0 |
0.086172 |
0.121 |
PR200L |
5650.2 |
6051.9 |
6460.4 |
4830.5 |
>9392 |
0.93 |
0.26908 |
0.151 |
CORON |
5472. |
5926.3 |
6460.4 |
4926.1 |
|
0.475 |
0.13743 |
0.156 |
G800L |
7506.4 |
7594.9 |
7000. |
2614.3 |
>6000 |
0.902 |
0.22724 |
0.110 |
Ramp Filters |
|||
Filter |
Central |
Δ λ |
Camera |
FR388N |
3710-4050 |
2% |
HRC |
FR656N |
6270-6850 |
2% |
HRC |
FR914M |
7570-10710 |
9% |
HRC |
FR459M |
3810-5370 |
9% |
HRC |
FR505N |
4820-5270 |
2% |
HRC |
Please refer to Bohlin and Tsvetanov (ISR ACS 00-05) for details about calculation of peak transmission for ramp filters.