DOLORES (Device Optimized for the LOw RESolution), LRS in short, is a low resolution  spectrograph and camara permanently installed at the Nasmyth B focus of the Telescopio Nazionale Galileo. Its design allows to perform imaging and low resolution spectoscopy observations. The instrument is based on a collimator and on a  focal reducer and camara. To select the observing mode GRISMS, for the low resolution spectroscopy, or optical filters,  for multiband photometry can be inserted into the optical path soon after the collimator. Slits are carried by a slider, Tram , located at the telescope focal plane. The Tram can carry up to 5 long slits or Multi Object Spectroscopy ( MOS ) plates. Thanks to its design switching from imaging to spectroscopy takes a short time ( about 2 minutes in the worst case ). The camera is equipped with a 2048 x 2048 E2V 4240 Thinned back-illuminated, deep-depleted, Astro-BB coated CCD with a pixel size of 13.5 µ.
The Field of view is 8.6 x 8.6 arcmin with a 0.252 arcsec/pix scale.