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1. Spatial Vignetting on the chip and the Acquisition TV Reported by : dlp,pms Date : August 1997 On the lamps flats (+ sky flats) quite severe vignetting is seen on the bottom end of the chip over about 50 pixels. The drop-off is quite sharp. This appeared to be a transient feature. SJST could not reproduce the effect two nights after it was reported, either with lamp-flats, sky-flats or moving a star up and down the previously observed vigentted region. Has re-appeared once since the original report. If an object is moved along the slit to the left of the TV, it appears also to be vignetted on the screen in the control room. However it is likely that these are unrelated effects, as the TV vignetting can be reproduced when the chip effect is not observed. The TV vignetting is not a problem mbrox/crb/dlp had a look inside IDS, but could not see any obvious cause.
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