Recent Info

Recent Information Not Yet In the Manual

September 10, 1999: On-chip binning (2x2) has been tested for acquisition and preliminary processing (through CCDPROC). Readout time is about 70 seconds.
August 26, 1999: Astrometry Error: See message from Frank Valdes
August 13, 1999: New filters have arrived -- we now offer Washington M and DDO 51 filters. The characteristics of these filters are now posted on the Mosaic Filter page.
April 20, 1999: The U-band filter vignettes slightly at the 4-m. At the edges, the degree of vignetting produces a 20% loss of light. The affected region ramps up to 0% loss at 150-200 pixels from the edge.

April 7, 1999: The manual refers to the dither pattern as lauer.dat. That pattern was devised to correct for the bad columns in the engineering CCDs. With the new CCDs, we are using the dither pattern referred to as todd.dat, shown below:

# Todd Boroson's canned dither scheme for the NOAO mosaic
# Offset relative to current telescope position
# RA (pixels)   Dec (pixels)
   0               0
 200            -200
-200             200
 100             100
-100            -100

April 7, 1999: Focus in the U filter at the 4-m is 300 units more negative than the R filter. The manual incorrectly states 100 units more negative.

Last Modified by George Jacoby on 10 September 1999