| Telescope | MDM 1.3m |
| Date | 11/21/97 |
| Instrument | Echelle CCD |
| Filter | V |
| Exposure Time |
15 sec |
| Other | twilight flat |
Problem:The dark current structure does not show up in this image due to the fact that the exposure time is short (15 s), so the dark current levels are very small, and the fact that the signal level in this twilight flat is significantly higher than the signal due to the dark current. Since dark current did not affect this flatfield image, the data images retained a dark current signature after processing. |
Fix:Make sure the CCD is appropriately cooled or take dark frames with which to subtract out the dark current. |
0 sec Zero frame with different structure
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