Figure 4: The command ccdinfo produces a listing of the current parameters in effect, and reminds you of the gain.

ccdinfo
        (gain = 1)              Gain setting 
    (preflash = 0.)             Preflash time (seconds) 
        (xsum = 1)              pixels summed in X direction 
        (ysum = 1)              pixels summed in Y direction 
      (xstart = 1)              Start of ROI in X 
      (ystart = 1)              Start of ROI in Y 
       (xsize = 4096)           Size  of ROI in X 
       (ysize = 4096)           Size  of ROI in Y 
      (extend = "separate")     Method of extending ROI to include overscan 
      (xskip1 = 0)              X pixels to skip at start of overscan  
      (xskip2 = 0)              X pixels to skip at end   of overscan  
      (xtrim1 = 0)              X pixels to trim at start of data  
      (xtrim2 = 0)              X pixels to trim at end   of data  
      (ytrim1 = 0)              Y pixels to trim at start of data  
      (ytrim2 = 0)              Y pixels to trim at end   of data  
  (amplifiers = "lowerfour")    Readout amplifiers to be used 
     (pixsize = 15.)            Pixel size in microns
    (nxpixels = 4096)           Detector size in X 
    (nypixels = 4096)           Detector size in Y 
   (noverscan = 64)             Number of overscan pixels 
     (detname = "MM2")          
        (mode = "ql")           
 

                        *** Table of gain values ***

       Detector = Mini-Mosaic, 4160 x 4096 (64 overscan)
                  
       dcsT  GAIN   Read_Noise        Gain      Readout Time
       (us)   #        (e-)         (e-/ADU)      (sec)
        ---  ---   -------------   -----------   --------
 1:    5      3         6.0           1.4         182
 2:    8      4         4.5           0.9         207 
        
               Default Gain setting is #3                      

        *** Select gain setting from the first column

        *** The current gain setting is 1