The Calibrate command will calibrate the currently selected image. If a valid calibration is not set, then an error message appears. If the calibration was set on a previous MaxIm DL session, the calibration files will be loaded again, if still available.

The FITS key CALSTAT will be updated after an image is successfully calibrated.  Four different letters may appear in this key.  'B' appears to indicate that the image was bias-corrected, 'D' to indicate that a dark frame was applied, and 'F' indicates that a flat field was used.  The letter 'M' may also appear, but not as a result of this command; it indicates that the image was generated by MaxIm's Create Master Frames function.

Both monochrome and color images may be calibrated. Subframe images, of either type, may be calibrated using groups of full-frame calibration images.