New Dome Flat Exposure Times


In August 2003 a new flat field spot was installed at the 4 meter (see the picture below). The flat field source lamps and the filters in front of the low lamps were all replaced. As a result, we've found the dome flat exposure times listed in the manual have changed. New suggested lamp settings and exposure times are listed below. These give around 10,000 counts above bias.

The New Flat Field at the 4 meter

Flat Field Lamp Settings and Exposure Times

Filter
Lamp Setting
Exposure Time
U
High 53V
8s
B
Low 53V
18s
V
Low 53V
12s
R
Low 53V
12s
I
Low 53V
15s
Ha
High 20V
9s
Ha4
High 20V
8s
Ha16
High 20V
9s
O3
High 53V
2s
g
Low 53V
10s
r
Low 53V
12s
i
Low 53V
18s
z
Low 53V
22s
D51
High 20V
35s
Wash M
Low 53V
18s
VR
Low 53V
8s
Bw
Low 53V
15s
wh
Low 53V
3s


Updated November 14, 2003   heidis@noao.edu