LDSS3 – Updates

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LDSS3 – Updates


Any binning other than 1x1 with LDSS-3 could cause issues with the bias levels. It has also been reported that the shutter fails to open 30% of the times using binning 2x2.

New instructions for LDSS-3 masks

As of February 2022, the mask-blanks stock is critically low. For this reason the science programs that need to cut their masks in the central position only, should follow the instructions below until further notice.

Experiments with LDSS-3 masks indicate that the blank position4 only has small measured offsets at +/- 1.5 pixels or less and therefore astronomers are requested to extend slits by about 0.5” in each direction, when possible without conflict, so that the masks can be cut from used blank stock at position4. In order to achieve this, when creating the .nc file, the same .SMF file needs to be repeated 5 times, so that positions-0 to 4 are populated. Then the local crew can select and cut only position-4. 


As of Nov 18th (2021) a new version of the LDSS-3 GUI (Version 0048) is running on guanaco.

May 2017

  • As of May 2017 the subraster mode is not offered because of problems with the readout of the images. 
  • The 'slow' mode in readout speed should not be used (details in the manual) 

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