DOLORES (DEVICE OPTIMIZED FOR LOW       
        RESOLUTION)
=================================

  Instrument Overview                                                         
  ===================                                                         
    DOLORES (Device Optimized for LOw RESolution) is a focal reducer          
    instrument installed at the Nasmyth B focus of the Telescopio Nazionale   
    Galileo at La Palma. The detector is a 2048 x 2048 E2V 4240 thinned       
    back-illuminated, deep-depleted, Astro-BB coated CCD with a pixel size of 
    13.5 microns. The scale is 0.252 arcsec/pixel which yields a field of view
    of about  8.6 x 8.6 arcmin. The instrument allows imaging through broad   
    and narrow band filters as well as spectroscopic observations with        
    resolving powers between RS = ~500 and RS = ~6000. A multi-slit mode,     
    based on custom masks manufactured by a dedicate cutting machine, is also 
    available.                                                                
                                                                              
    Grisms:                                                                   
                                                                              
    Name    disp.   wavelength range (A)    Resolution                        
            A/Pix   min     central max     (1' slit)                         
                                                                              
    LR-B    2.52    3000    5850    8430    585                               
    LR-R    2.61    4470    7400    10073   714                               
    V390    0.26    3634    3900    4166    3766                              
    V486    0.20    4612    4725    4838    5953                              
    V510    0.22    4875    5100    5325    5950                              
    V589    0.27    5619    5895    6171    5502                              
    V656    0.32    6232    6560    6888    5248                              
    V860    0.44    8149    8600    9051    4000                              
    VHRV    0.95    4752    5725    6698    1527                              
    VHRR    0.70    6238    7000    7717    2513                              
    VHRI    0.68    7433    8130    8826    3035                              
                                                                              
    Notes:                                                                    
                                                                              
    1.  The LR-R Grism has a built-in order-blocking filter cutting blueward  
    ~5000 angstroms; nevertheless, blue objects will show noticeable          
    second-order                                                              
    overlap above ~9500 angstroms.                                            
    2.  The V390 Grism is not mounted on the grism wheel and may be used ONLY 
    in                                                                        
    visitor mode. Users interested in using this grism must explicitly request
    it in the Observing Proposal.                                             
    3.  The V860, VHRR, and VHRI Grisms suffer from significant second-order  
    effect and will be automatically coupled  with the ~560 nm cut-on filter  
    available on the filters wheel.                                           
    4.  Resolution calculated for a 1' Slit.                                  
    5.  Please note that there aren't suitable wavelength calibration lamps   
    for                                                                       
    the V486 GRISM.