1. 1 PreCam Flat Field QA Sahar Allam and Douglas Tucker 27 January 2011

2. 2 Flat Field Lamp Control Box

3. 3 DES grizy Filters by Asahi 470nm740nm905nm970nm1000nm

4. 4 Flat Field Brightness vs. Time (MJD) Measured in a 100x100 pixel “box” in Amp A of CCD 1

5. 5 Flat Field Brightness vs. Time (MJD) Measured in a 100x100 pixel “box” in Amp A of CCD 1

6. 6 Flat Field Brightness vs. Time (MJD) Measured in a 100x100 pixel “box” in Amp A of CCD 1

7. 7 Flat Field Brightness vs. Time (MJD) Measured in a 100x100 pixel “box” in Amp A of CCD 1

8. 8 Flat Field Brightness vs. Time (MJD) Measured in a 100x100 pixel “box” in Amp A of CCD 1

9. 9 Flat Field Brightness vs. Time (MJD) Measured in a 100x100 pixel “box” in Amp A of CCD 1

10. 10 Results 1.Dome lights on during flats for the night of MJD 55537? 2.Shutter problems between MJD 55553 and 55566 Broken or sticky 3.No problems with i- or y-band flats aside from period where we experienced shutter problems. 4.Problem with z-band flats starting on MJD 55545. Problem with 905nm LED? No apparent problems with i-band flats, which might indicate the 970nm or 1000nm LED. 5.Problem with g- and r-band flats starting on MJD 55572. As Pat Seitzer reported, white light LED was not working when he arrived.