• The linearity correction applies to the detector and so only needs one set of calibration data and is independent of filter.

• Flats are obviously filter dependent.

• And, dark current is integration time-dependent, so dark image exposure times must match science and flat exposures. The old trick of scaling flats by the time fraction doesn't work here.

• the "exposure time" you set and that shows up in the FITS headers is not correct, as the time for one readout of the detector must be added. The current "exposure time" is the dwell time between the end of the first readout and the start of the second readout.

• One measures the readout time by comparing the dark-corrected count rates for two different exposure time images from the linearity series and fitting for the read time.

Adjusting Bypass Valve