The information on this page is an update of that presented in Dolphin (2000), and is published in Dolphin (2009). The necessitation of the update is for a few reasons:

More recent observations of Omega Cen (through June 2007)
Improved versions of HSTphot to reduce the data
Improved functional forms for the fitting

The limitation of the new calibration equations is that they only consider cold (after April 1994) observations.

Contribution for 2002 HST Calibration Workshop proceedings available here.

Equations last updated May 13, 2009.

Previous equations:

WF4 Anomaly

Since SM3B (March 2002), WF4 data have suffered from what is called the "WF4 Anomaly". Further details about this can be found at STScI's WFPC2 pages, most notably ISR 0502.

From the residuals to the CTE and zero point correction solutions presented here, two key times can be located. Beginning at the time of SM3B (March 2002), an increasing number of images with low bias appeared (as has been documented well in the STScI sources referenced above). In addition, my preliminary analysis indicates a significant change to the XCTE losses at this time (perhaps tripled or more).

The second key time was the temperature reductions in the WF4 electronics that were designed to combat the anomaly. This had the effect of significantly reducing the YCTE loss (perhaps by 20%).

The photometric effects have not yet been adequately calibrated in this work, so I have omitted all WF4 data from March 2002 onwards in deriving the equations below. This means that calibration of WF4 data may not be as reliable as the other chips, even if one applies the streak and count level corrections as recommended in ISR 0502.

The remaining data (PC, WF2, and WF3) fit the lifetime curves very well, with average residuals under 1% per chip or filter, and less than 0.02 magnitudes per dex of star brightness or background level.

CTE Correction

The recommended CTE correction below is more complex than usual CTE equations, to allow for the fact that the star brightness is not constant as it is read out, and therefore that the CTE loss per pixel changes during readout. The recipe for correction is as follows:

First, calculate the following variable values:

lbg = ln(sqrt ( background/electrons^2 + 1 )) - 1
yr = (MJD - 49461.9) / 365.25

Second, correct for the CTE loss in X readout:

XCTE (mags) = 0.0077*exp(-0.50*lbg)*(1+0.10*yr)*x/800

Third, calculate lct using:

lct = ln(counts/electrons) + 0.921*XCTE - 7

Finally, correct for the CTE loss in Y readout:

c1 = max(1.0-0.201*lbg+0.039*lbg*lct+0.002*lct,0.15)
c2 = 0.96*(yr-0.0255*yr*yr)*exp(-0.450*lct)
YCTE (mags) = 2.41*ln(exp(0.02239*c1*y/800)*(1+c2)-c2)

Uncertainties of the parameters:

49461.9 +/- 0.1
0.0077 +/- 0.0008
0.50 +/- 0.06
0.10 +/- 0.03
0.201 +/- 0.002
0.039 +/- 0.002
0.002 +/- 0.003
0.15 +/- 0.03
0.96 +/- 0.02
0.0255 +/- 0.0004
0.450 +/- 0.004
2.41 +/- 0.02
0.02239 +/- 0.00001

Note that the background level should equal the true background of the image. For a sky measured near the star, there is usually some starlight in the sky annulus that can cause confusion. For images with low background levels, this can become a major fraction of the measured background.

Also note that the choice of photometry parameters can affect the CTE solution, as CTE loss affects the PSF for very faint sources. The solution here is for the default HSTphot parameters -- a PSF-fit inside a small (3 pixel PC, 2 pixel WFC) aperture.

Zero Points relative to Holtzman et al. (1995)

GAIN=7 GAIN=14

Filter PC1 WFC2 WFC3 WFC4 PC1 WFC2 WFC3 WFC4

F439W 0.065 +/- 0.008 0.067 +/- 0.004 0.060 +/- 0.004 0.073 +/- 0.004 0.045 +/- 0.002 0.065 +/- 0.001 0.041 +/- 0.001 0.063 +/- 0.002

F555W 0.045 +/- 0.003 0.044 +/- 0.001 0.039 +/- 0.002 0.048 +/- 0.001 0.040 +/- 0.002 0.034 +/- 0.001 0.036 +/- 0.001 0.051 +/- 0.002

F675W 0.060 +/- 0.007 0.061 +/- 0.004 0.052 +/- 0.004 0.070 +/- 0.003 0.041 +/- 0.002 0.054 +/- 0.001 0.046 +/- 0.001 0.047 +/- 0.003

F814W 0.013 +/- 0.002 0.036 +/- 0.001 0.030 +/- 0.001 0.032 +/- 0.001 0.025 +/- 0.001 0.036 +/- 0.001 0.024 +/- 0.001 0.030 +/- 0.001

note: add these values to Holtzman-calibrated magnitudes

	GAIN=7	GAIN=14
Filter	PC1	WFC2	WFC3	WFC4	PC1	WFC2	WFC3	WFC4
F439W	0.065 +/- 0.008	0.067 +/- 0.004	0.060 +/- 0.004	0.073 +/- 0.004	0.045 +/- 0.002	0.065 +/- 0.001	0.041 +/- 0.001	0.063 +/- 0.002
F555W	0.045 +/- 0.003	0.044 +/- 0.001	0.039 +/- 0.002	0.048 +/- 0.001	0.040 +/- 0.002	0.034 +/- 0.001	0.036 +/- 0.001	0.051 +/- 0.002
F675W	0.060 +/- 0.007	0.061 +/- 0.004	0.052 +/- 0.004	0.070 +/- 0.003	0.041 +/- 0.002	0.054 +/- 0.001	0.046 +/- 0.001	0.047 +/- 0.003
F814W	0.013 +/- 0.002	0.036 +/- 0.001	0.030 +/- 0.001	0.032 +/- 0.001	0.025 +/- 0.001	0.036 +/- 0.001	0.024 +/- 0.001	0.030 +/- 0.001

Additional Offsets for Non-Standard Filters

Filter Std Filt offset

F300W F336W -0.000 +/- 0.000

F380W F439W 0.077 +/- 0.003

F410M F439W 0.051 +/- 0.003

F450W F439W -0.007 +/- 0.003

F467M F439W -0.068 +/- 0.003

F547M F555W -0.004 +/- 0.002

F569W F555W -0.021 +/- 0.002

F606W F555W -0.017 +/- 0.002

F622W F675W -0.013 +/- 0.005

F702W F675W 0.006 +/- 0.003

F785LP F814W 0.007 +/- 0.003

F791W F814W -0.018 +/- 0.003

F850LP F814W 0.008 +/- 0.005

F1042M F814W 0.071 +/- 0.010

note: add these values plus the corresponding calibration from the standard filter table to Holtzman-calibrated magnitudes

Filter	Std Filt	offset
F300W	F336W	-0.000 +/- 0.000
F380W	F439W	0.077 +/- 0.003
F410M	F439W	0.051 +/- 0.003
F450W	F439W	-0.007 +/- 0.003
F467M	F439W	-0.068 +/- 0.003
F547M	F555W	-0.004 +/- 0.002
F569W	F555W	-0.021 +/- 0.002
F606W	F555W	-0.017 +/- 0.002
F622W	F675W	-0.013 +/- 0.005
F702W	F675W	0.006 +/- 0.003
F785LP	F814W	0.007 +/- 0.003
F791W	F814W	-0.018 +/- 0.003
F850LP	F814W	0.008 +/- 0.005
F1042M	F814W	0.071 +/- 0.010

WFPC2 Instrumental Magnitudes

GAIN=7 Zero Points for 1 DN/sec

Filter PC1 WFC2 WFC3 WFC4
F380W 21.000 +/- 0.009 21.012 +/- 0.005 21.012 +/- 0.005 20.996 +/- 0.005

F410M 19.360 +/- 0.009 19.373 +/- 0.006 19.373 +/- 0.005 19.356 +/- 0.005

F439W 20.874 +/- 0.008 20.886 +/- 0.004 20.886 +/- 0.004 20.870 +/- 0.004

F450W 21.970 +/- 0.009 21.982 +/- 0.005 21.982 +/- 0.005 21.966 +/- 0.005

F467M 19.895 +/- 0.009 19.908 +/- 0.006 19.908 +/- 0.005 19.891 +/- 0.005

F547M 21.618 +/- 0.003 21.627 +/- 0.002 21.630 +/- 0.003 21.609 +/- 0.002

F555W 22.508 +/- 0.003 22.517 +/- 0.001 22.520 +/- 0.002 22.499 +/- 0.001

F569W 22.181 +/- 0.003 22.190 +/- 0.002 22.193 +/- 0.003 22.172 +/- 0.002

F606W 22.850 +/- 0.003 22.859 +/- 0.002 22.862 +/- 0.003 22.841 +/- 0.002

F622W 22.329 +/- 0.009 22.340 +/- 0.006 22.338 +/- 0.007 22.327 +/- 0.006

F675W 22.033 +/- 0.007 22.044 +/- 0.004 22.042 +/- 0.004 22.030 +/- 0.003

F702W 22.432 +/- 0.008 22.443 +/- 0.004 22.442 +/- 0.005 22.430 +/- 0.004

F785LP 20.635 +/- 0.003 20.668 +/- 0.003 20.670 +/- 0.003 20.642 +/- 0.003

F791W 21.441 +/- 0.004 21.473 +/- 0.004 21.475 +/- 0.004 21.447 +/- 0.004

F814W 21.591 +/- 0.002 21.624 +/- 0.001 21.625 +/- 0.001 21.598 +/- 0.001

F850LP 19.899 +/- 0.005 19.932 +/- 0.005 19.934 +/- 0.005 19.906 +/- 0.005

F1042M 16.189 +/- 0.010 16.222 +/- 0.010 16.224 +/- 0.010 16.196 +/- 0.010

Filter	PC1	WFC2	WFC3	WFC4
F380W	21.000 +/- 0.009	21.012 +/- 0.005	21.012 +/- 0.005	20.996 +/- 0.005
F410M	19.360 +/- 0.009	19.373 +/- 0.006	19.373 +/- 0.005	19.356 +/- 0.005
F439W	20.874 +/- 0.008	20.886 +/- 0.004	20.886 +/- 0.004	20.870 +/- 0.004
F450W	21.970 +/- 0.009	21.982 +/- 0.005	21.982 +/- 0.005	21.966 +/- 0.005
F467M	19.895 +/- 0.009	19.908 +/- 0.006	19.908 +/- 0.005	19.891 +/- 0.005
F547M	21.618 +/- 0.003	21.627 +/- 0.002	21.630 +/- 0.003	21.609 +/- 0.002
F555W	22.508 +/- 0.003	22.517 +/- 0.001	22.520 +/- 0.002	22.499 +/- 0.001
F569W	22.181 +/- 0.003	22.190 +/- 0.002	22.193 +/- 0.003	22.172 +/- 0.002
F606W	22.850 +/- 0.003	22.859 +/- 0.002	22.862 +/- 0.003	22.841 +/- 0.002
F622W	22.329 +/- 0.009	22.340 +/- 0.006	22.338 +/- 0.007	22.327 +/- 0.006
F675W	22.033 +/- 0.007	22.044 +/- 0.004	22.042 +/- 0.004	22.030 +/- 0.003
F702W	22.432 +/- 0.008	22.443 +/- 0.004	22.442 +/- 0.005	22.430 +/- 0.004
F785LP	20.635 +/- 0.003	20.668 +/- 0.003	20.670 +/- 0.003	20.642 +/- 0.003
F791W	21.441 +/- 0.004	21.473 +/- 0.004	21.475 +/- 0.004	21.447 +/- 0.004
F814W	21.591 +/- 0.002	21.624 +/- 0.001	21.625 +/- 0.001	21.598 +/- 0.001
F850LP	19.899 +/- 0.005	19.932 +/- 0.005	19.934 +/- 0.005	19.906 +/- 0.005
F1042M	16.189 +/- 0.010	16.222 +/- 0.010	16.224 +/- 0.010	16.196 +/- 0.010

GAIN=14 Zero Points for 1 DN/sec

Filter PC1 WFC2 WFC3 WFC4
F380W 20.234 +/- 0.004 20.255 +/- 0.003 20.237 +/- 0.003 20.258 +/- 0.003

F410M 18.595 +/- 0.004 18.616 +/- 0.004 18.598 +/- 0.004 18.618 +/- 0.004

F439W 20.108 +/- 0.002 20.129 +/- 0.001 20.111 +/- 0.001 20.132 +/- 0.002

F450W 21.204 +/- 0.004 21.225 +/- 0.003 21.207 +/- 0.003 21.228 +/- 0.004

F467M 19.130 +/- 0.004 19.151 +/- 0.004 19.133 +/- 0.004 19.153 +/- 0.004

F547M 20.867 +/- 0.003 20.863 +/- 0.002 20.871 +/- 0.002 20.884 +/- 0.002

F555W 21.757 +/- 0.002 21.753 +/- 0.001 21.761 +/- 0.001 21.774 +/- 0.002

F569W 21.430 +/- 0.003 21.426 +/- 0.002 21.434 +/- 0.002 21.447 +/- 0.003

F606W 22.099 +/- 0.003 22.095 +/- 0.002 22.103 +/- 0.002 22.116 +/- 0.002

F622W 21.564 +/- 0.006 21.579 +/- 0.005 21.576 +/- 0.005 21.576 +/- 0.006

F675W 21.268 +/- 0.002 21.282 +/- 0.001 21.280 +/- 0.001 21.279 +/- 0.003

F702W 21.667 +/- 0.004 21.682 +/- 0.003 21.679 +/- 0.003 21.679 +/- 0.004

F785LP 19.902 +/- 0.003 19.915 +/- 0.003 19.908 +/- 0.003 19.912 +/- 0.003

F791W 20.707 +/- 0.004 20.720 +/- 0.004 20.713 +/- 0.004 20.717 +/- 0.004

F814W 20.857 +/- 0.001 20.870 +/- 0.001 20.863 +/- 0.001 20.867 +/- 0.001

F850LP 19.166 +/- 0.005 19.179 +/- 0.005 19.172 +/- 0.005 19.176 +/- 0.005

F1042M 15.456 +/- 0.010 15.468 +/- 0.010 15.462 +/- 0.010 15.466 +/- 0.010

Filter	PC1	WFC2	WFC3	WFC4
F380W	20.234 +/- 0.004	20.255 +/- 0.003	20.237 +/- 0.003	20.258 +/- 0.003
F410M	18.595 +/- 0.004	18.616 +/- 0.004	18.598 +/- 0.004	18.618 +/- 0.004
F439W	20.108 +/- 0.002	20.129 +/- 0.001	20.111 +/- 0.001	20.132 +/- 0.002
F450W	21.204 +/- 0.004	21.225 +/- 0.003	21.207 +/- 0.003	21.228 +/- 0.004
F467M	19.130 +/- 0.004	19.151 +/- 0.004	19.133 +/- 0.004	19.153 +/- 0.004
F547M	20.867 +/- 0.003	20.863 +/- 0.002	20.871 +/- 0.002	20.884 +/- 0.002
F555W	21.757 +/- 0.002	21.753 +/- 0.001	21.761 +/- 0.001	21.774 +/- 0.002
F569W	21.430 +/- 0.003	21.426 +/- 0.002	21.434 +/- 0.002	21.447 +/- 0.003
F606W	22.099 +/- 0.003	22.095 +/- 0.002	22.103 +/- 0.002	22.116 +/- 0.002
F622W	21.564 +/- 0.006	21.579 +/- 0.005	21.576 +/- 0.005	21.576 +/- 0.006
F675W	21.268 +/- 0.002	21.282 +/- 0.001	21.280 +/- 0.001	21.279 +/- 0.003
F702W	21.667 +/- 0.004	21.682 +/- 0.003	21.679 +/- 0.003	21.679 +/- 0.004
F785LP	19.902 +/- 0.003	19.915 +/- 0.003	19.908 +/- 0.003	19.912 +/- 0.003
F791W	20.707 +/- 0.004	20.720 +/- 0.004	20.713 +/- 0.004	20.717 +/- 0.004
F814W	20.857 +/- 0.001	20.870 +/- 0.001	20.863 +/- 0.001	20.867 +/- 0.001
F850LP	19.166 +/- 0.005	19.179 +/- 0.005	19.172 +/- 0.005	19.176 +/- 0.005
F1042M	15.456 +/- 0.010	15.468 +/- 0.010	15.462 +/- 0.010	15.466 +/- 0.010

note: WFPC2mag = -2.5 log (DN/s) + ZP(FG) - CTE
ZP(FG) from above tables
CTE calculated from above equations

UBVRI Transformations

GAIN=7

Filter SMAG SCOL ZP(PC1) ZP(WFC2) ZP(WFC3) ZP(WFC4) T1 T2 Cmin Cmax

F380W B (B-V) 21.025 21.037 21.037 21.021 -0.581 0.777 ... 0.5

F380W B (B-V) 21.377 21.389 21.389 21.373 -0.943 0.103 0.5 ...

F410M B (B-V) 19.670 19.683 19.683 19.666 -0.183 -0.287 ... ...

F439W B (U-B) 20.861 20.873 20.873 20.857 -0.103 -0.046 ... ...

F439W B (B-V) 20.874 20.886 20.886 20.870 0.003 -0.088 ... ...

F439W B (B-R) 20.868 20.880 20.880 20.864 0.019 -0.049 ... ...

F439W B (B-I) 20.871 20.883 20.883 20.867 0.005 -0.023 ... ...

F450W B (B-V) 21.972 21.984 21.984 21.968 0.230 -0.003 ... ...

F467M B (B-V) 19.902 19.915 19.915 19.898 0.480 -0.299 ... 0.5

F467M B (B-V) 19.853 19.866 19.866 19.849 0.432 -0.002 0.5 ...

F547M V (B-V) 21.613 21.622 21.625 21.604 0.031 -0.039 ... 1.0

F547M V (B-V) 21.565 21.574 21.577 21.556 0.056 -0.016 1.0 ...

F547M V (V-I) 21.613 21.622 21.625 21.604 0.027 -0.032 ... 1.1

F547M V (V-I) 21.565 21.574 21.577 21.556 0.049 -0.013 1.1 ...

F555W V (U-V) 22.489 22.498 22.501 22.480 -0.014 0.005 ... ...

F555W V (B-V) 22.508 22.517 22.520 22.499 -0.060 0.033 ... ...

F555W V (V-R) 22.513 22.522 22.525 22.504 -0.121 0.120 ... ...

F555W V (V-I) 22.508 22.517 22.520 22.499 -0.052 0.027 ... ...

F569W V (V-I) 22.179 22.188 22.191 22.170 0.089 -0.003 ... 2.0

F569W V (V-I) 22.511 22.520 22.523 22.502 -0.125 0.022 2.0 ...

F606W V (B-V) 22.859 22.868 22.871 22.850 0.293 0.015 ... 1.7

F606W V (B-V) 23.649 23.658 23.661 23.640 -0.284 0.081 1.7 ...

F606W V (V-I) 22.859 22.868 22.871 22.850 0.254 0.012 ... 2.0

F606W V (V-I) 23.649 23.658 23.661 23.640 -0.247 0.065 2.0 ...

F622W R (V-R) 22.343 22.354 22.352 22.341 -0.252 -0.111 ... ...

F675W R (U-R) 22.053 22.064 22.062 22.050 0.039 -0.007 ... ...

F675W R (B-R) 22.034 22.045 22.043 22.031 0.092 -0.017 ... ...

F675W R (V-R) 22.033 22.044 22.042 22.030 0.253 -0.125 ... ...

F675W R (R-I) 22.024 22.035 22.033 22.021 0.273 -0.066 ... ...

F702W R (V-R) 22.437 22.448 22.447 22.435 0.343 -0.177 ... 0.6

F702W R (V-R) 22.315 22.326 22.325 22.313 0.486 -0.079 0.6 ...

F785LP I (V-I) 20.638 20.671 20.673 20.645 0.091 0.020 ... ...

F791W I (V-I) 21.441 21.473 21.475 21.447 -0.029 -0.004 ... 1.0

F791W I (V-I) 21.482 21.514 21.516 21.488 -0.084 0.011 1.0 ...

F814W I (U-I) 21.567 21.600 21.601 21.574 -0.018 0.002 ... ...

F814W I (B-I) 21.587 21.620 21.621 21.594 -0.031 0.007 ... ...

F814W I (V-I) 21.591 21.624 21.625 21.598 -0.062 0.025 ... ...

F814W I (R-I) 21.591 21.624 21.625 21.598 -0.112 0.084 ... ...

F850LP I (V-I) 19.881 19.914 19.916 19.888 0.160 0.023 ... ...

F1042M I (V-I) 16.136 16.169 16.171 16.143 0.350 0.022 ... ...

Filter	SMAG	SCOL	ZP(PC1)	ZP(WFC2)	ZP(WFC3)	ZP(WFC4)	T1	T2	Cmin	Cmax
F380W	B	(B-V)	21.025	21.037	21.037	21.021	-0.581	0.777	...	0.5
F380W	B	(B-V)	21.377	21.389	21.389	21.373	-0.943	0.103	0.5	...
F410M	B	(B-V)	19.670	19.683	19.683	19.666	-0.183	-0.287	...	...
F439W	B	(U-B)	20.861	20.873	20.873	20.857	-0.103	-0.046	...	...
F439W	B	(B-V)	20.874	20.886	20.886	20.870	0.003	-0.088	...	...
F439W	B	(B-R)	20.868	20.880	20.880	20.864	0.019	-0.049	...	...
F439W	B	(B-I)	20.871	20.883	20.883	20.867	0.005	-0.023	...	...
F450W	B	(B-V)	21.972	21.984	21.984	21.968	0.230	-0.003	...	...
F467M	B	(B-V)	19.902	19.915	19.915	19.898	0.480	-0.299	...	0.5
F467M	B	(B-V)	19.853	19.866	19.866	19.849	0.432	-0.002	0.5	...
F547M	V	(B-V)	21.613	21.622	21.625	21.604	0.031	-0.039	...	1.0
F547M	V	(B-V)	21.565	21.574	21.577	21.556	0.056	-0.016	1.0	...
F547M	V	(V-I)	21.613	21.622	21.625	21.604	0.027	-0.032	...	1.1
F547M	V	(V-I)	21.565	21.574	21.577	21.556	0.049	-0.013	1.1	...
F555W	V	(U-V)	22.489	22.498	22.501	22.480	-0.014	0.005	...	...
F555W	V	(B-V)	22.508	22.517	22.520	22.499	-0.060	0.033	...	...
F555W	V	(V-R)	22.513	22.522	22.525	22.504	-0.121	0.120	...	...
F555W	V	(V-I)	22.508	22.517	22.520	22.499	-0.052	0.027	...	...
F569W	V	(V-I)	22.179	22.188	22.191	22.170	0.089	-0.003	...	2.0
F569W	V	(V-I)	22.511	22.520	22.523	22.502	-0.125	0.022	2.0	...
F606W	V	(B-V)	22.859	22.868	22.871	22.850	0.293	0.015	...	1.7
F606W	V	(B-V)	23.649	23.658	23.661	23.640	-0.284	0.081	1.7	...
F606W	V	(V-I)	22.859	22.868	22.871	22.850	0.254	0.012	...	2.0
F606W	V	(V-I)	23.649	23.658	23.661	23.640	-0.247	0.065	2.0	...
F622W	R	(V-R)	22.343	22.354	22.352	22.341	-0.252	-0.111	...	...
F675W	R	(U-R)	22.053	22.064	22.062	22.050	0.039	-0.007	...	...
F675W	R	(B-R)	22.034	22.045	22.043	22.031	0.092	-0.017	...	...
F675W	R	(V-R)	22.033	22.044	22.042	22.030	0.253	-0.125	...	...
F675W	R	(R-I)	22.024	22.035	22.033	22.021	0.273	-0.066	...	...
F702W	R	(V-R)	22.437	22.448	22.447	22.435	0.343	-0.177	...	0.6
F702W	R	(V-R)	22.315	22.326	22.325	22.313	0.486	-0.079	0.6	...
F785LP	I	(V-I)	20.638	20.671	20.673	20.645	0.091	0.020	...	...
F791W	I	(V-I)	21.441	21.473	21.475	21.447	-0.029	-0.004	...	1.0
F791W	I	(V-I)	21.482	21.514	21.516	21.488	-0.084	0.011	1.0	...
F814W	I	(U-I)	21.567	21.600	21.601	21.574	-0.018	0.002	...	...
F814W	I	(B-I)	21.587	21.620	21.621	21.594	-0.031	0.007	...	...
F814W	I	(V-I)	21.591	21.624	21.625	21.598	-0.062	0.025	...	...
F814W	I	(R-I)	21.591	21.624	21.625	21.598	-0.112	0.084	...	...
F850LP	I	(V-I)	19.881	19.914	19.916	19.888	0.160	0.023	...	...
F1042M	I	(V-I)	16.136	16.169	16.171	16.143	0.350	0.022	...	...

GAIN=14

Filter SMAG SCOL ZP(PC1) ZP(WFC2) ZP(WFC3) ZP(WFC4) T1 T2 Cmin Cmax

F380W B (B-V) 20.259 20.280 20.262 20.283 -0.581 0.777 ... 0.5

F380W B (B-V) 20.611 20.632 20.614 20.635 -0.943 0.103 0.5 ...

F410M B (B-V) 18.905 18.926 18.908 18.928 -0.183 -0.287 ... ...

F439W B (U-B) 20.095 20.116 20.098 20.119 -0.103 -0.046 ... ...

F439W B (B-V) 20.108 20.129 20.111 20.132 0.003 -0.088 ... ...

F439W B (B-R) 20.102 20.123 20.105 20.126 0.019 -0.049 ... ...

F439W B (B-I) 20.105 20.126 20.108 20.129 0.005 -0.023 ... ...

F450W B (B-V) 21.206 21.227 21.209 21.230 0.230 -0.003 ... ...

F467M B (B-V) 19.137 19.158 19.140 19.160 0.480 -0.299 ... 0.5

F467M B (B-V) 19.088 19.109 19.091 19.111 0.432 -0.002 0.5 ...

F547M V (B-V) 20.862 20.858 20.866 20.879 0.031 -0.039 ... 1.0

F547M V (B-V) 20.814 20.810 20.818 20.831 0.056 -0.016 1.0 ...

F547M V (V-I) 20.862 20.858 20.866 20.879 0.027 -0.032 ... 1.1

F547M V (V-I) 20.814 20.810 20.818 20.831 0.049 -0.013 1.1 ...

F555W V (U-V) 21.738 21.734 21.742 21.755 -0.014 0.005 ... ...

F555W V (B-V) 21.757 21.753 21.761 21.774 -0.060 0.033 ... ...

F555W V (V-R) 21.762 21.758 21.766 21.779 -0.121 0.120 ... ...

F555W V (V-I) 21.757 21.753 21.761 21.774 -0.052 0.027 ... ...

F569W V (V-I) 21.428 21.424 21.432 21.445 0.089 -0.003 ... 2.0

F569W V (V-I) 21.760 21.756 21.764 21.777 -0.125 0.022 2.0 ...

F606W V (B-V) 22.108 22.104 22.112 22.125 0.293 0.015 ... 1.7

F606W V (B-V) 22.898 22.894 22.902 22.915 -0.284 0.081 1.7 ...

F606W V (V-I) 22.108 22.104 22.112 22.125 0.254 0.012 ... 2.0

F606W V (V-I) 22.898 22.894 22.902 22.915 -0.247 0.065 2.0 ...

F622W R (V-R) 21.578 21.593 21.590 21.590 -0.252 -0.111 ... ...

F675W R (U-R) 21.288 21.302 21.300 21.299 0.039 -0.007 ... ...

F675W R (B-R) 21.269 21.283 21.281 21.280 0.092 -0.017 ... ...

F675W R (V-R) 21.268 21.282 21.280 21.279 0.253 -0.125 ... ...

F675W R (R-I) 21.259 21.273 21.271 21.270 0.273 -0.066 ... ...

F702W R (V-R) 21.672 21.687 21.684 21.684 0.343 -0.177 ... 0.6

F702W R (V-R) 21.550 21.565 21.562 21.562 0.486 -0.079 0.6 ...

F785LP I (V-I) 19.905 19.918 19.911 19.915 0.091 0.020 ... ...

F791W I (V-I) 20.707 20.720 20.713 20.717 -0.029 -0.004 ... 1.0

F791W I (V-I) 20.748 20.761 20.754 20.758 -0.084 0.011 1.0 ...

F814W I (U-I) 20.833 20.846 20.839 20.843 -0.018 0.002 ... ...

F814W I (B-I) 20.853 20.866 20.859 20.863 -0.031 0.007 ... ...

F814W I (V-I) 20.857 20.870 20.863 20.867 -0.062 0.025 ... ...

F814W I (R-I) 20.857 20.870 20.863 20.867 -0.112 0.084 ... ...

F850LP I (V-I) 19.148 19.161 19.154 19.158 0.160 0.023 ... ...

F1042M I (V-I) 15.403 15.415 15.409 15.413 0.350 0.022 ... ...

Filter	SMAG	SCOL	ZP(PC1)	ZP(WFC2)	ZP(WFC3)	ZP(WFC4)	T1	T2	Cmin	Cmax
F380W	B	(B-V)	20.259	20.280	20.262	20.283	-0.581	0.777	...	0.5
F380W	B	(B-V)	20.611	20.632	20.614	20.635	-0.943	0.103	0.5	...
F410M	B	(B-V)	18.905	18.926	18.908	18.928	-0.183	-0.287	...	...
F439W	B	(U-B)	20.095	20.116	20.098	20.119	-0.103	-0.046	...	...
F439W	B	(B-V)	20.108	20.129	20.111	20.132	0.003	-0.088	...	...
F439W	B	(B-R)	20.102	20.123	20.105	20.126	0.019	-0.049	...	...
F439W	B	(B-I)	20.105	20.126	20.108	20.129	0.005	-0.023	...	...
F450W	B	(B-V)	21.206	21.227	21.209	21.230	0.230	-0.003	...	...
F467M	B	(B-V)	19.137	19.158	19.140	19.160	0.480	-0.299	...	0.5
F467M	B	(B-V)	19.088	19.109	19.091	19.111	0.432	-0.002	0.5	...
F547M	V	(B-V)	20.862	20.858	20.866	20.879	0.031	-0.039	...	1.0
F547M	V	(B-V)	20.814	20.810	20.818	20.831	0.056	-0.016	1.0	...
F547M	V	(V-I)	20.862	20.858	20.866	20.879	0.027	-0.032	...	1.1
F547M	V	(V-I)	20.814	20.810	20.818	20.831	0.049	-0.013	1.1	...
F555W	V	(U-V)	21.738	21.734	21.742	21.755	-0.014	0.005	...	...
F555W	V	(B-V)	21.757	21.753	21.761	21.774	-0.060	0.033	...	...
F555W	V	(V-R)	21.762	21.758	21.766	21.779	-0.121	0.120	...	...
F555W	V	(V-I)	21.757	21.753	21.761	21.774	-0.052	0.027	...	...
F569W	V	(V-I)	21.428	21.424	21.432	21.445	0.089	-0.003	...	2.0
F569W	V	(V-I)	21.760	21.756	21.764	21.777	-0.125	0.022	2.0	...
F606W	V	(B-V)	22.108	22.104	22.112	22.125	0.293	0.015	...	1.7
F606W	V	(B-V)	22.898	22.894	22.902	22.915	-0.284	0.081	1.7	...
F606W	V	(V-I)	22.108	22.104	22.112	22.125	0.254	0.012	...	2.0
F606W	V	(V-I)	22.898	22.894	22.902	22.915	-0.247	0.065	2.0	...
F622W	R	(V-R)	21.578	21.593	21.590	21.590	-0.252	-0.111	...	...
F675W	R	(U-R)	21.288	21.302	21.300	21.299	0.039	-0.007	...	...
F675W	R	(B-R)	21.269	21.283	21.281	21.280	0.092	-0.017	...	...
F675W	R	(V-R)	21.268	21.282	21.280	21.279	0.253	-0.125	...	...
F675W	R	(R-I)	21.259	21.273	21.271	21.270	0.273	-0.066	...	...
F702W	R	(V-R)	21.672	21.687	21.684	21.684	0.343	-0.177	...	0.6
F702W	R	(V-R)	21.550	21.565	21.562	21.562	0.486	-0.079	0.6	...
F785LP	I	(V-I)	19.905	19.918	19.911	19.915	0.091	0.020	...	...
F791W	I	(V-I)	20.707	20.720	20.713	20.717	-0.029	-0.004	...	1.0
F791W	I	(V-I)	20.748	20.761	20.754	20.758	-0.084	0.011	1.0	...
F814W	I	(U-I)	20.833	20.846	20.839	20.843	-0.018	0.002	...	...
F814W	I	(B-I)	20.853	20.866	20.859	20.863	-0.031	0.007	...	...
F814W	I	(V-I)	20.857	20.870	20.863	20.867	-0.062	0.025	...	...
F814W	I	(R-I)	20.857	20.870	20.863	20.867	-0.112	0.084	...	...
F850LP	I	(V-I)	19.148	19.161	19.154	19.158	0.160	0.023	...	...
F1042M	I	(V-I)	15.403	15.415	15.409	15.413	0.350	0.022	...	...

note: SMAG = -2.5 log (DN/s) + ZP(FS) + T1 SCOL + T2 SCOL^2 - CTE
ZP(FS), T1, and T2 from above tables
CTE calculated from above equations

References

"The Charge Transfer Efficiency and Calibration of WFPC2." Dolphin, 2000, A. E. PASP, 112, 1397

"WFPC2 Stellar Photometry with HSTphot." Dolphin, A. E. 2000, PASP, 112, 1383

"A Revised Characterization of the WFPC2 CTE Loss." Dolphin, A. E., PASP, 121, 655