Unless noted, all CCD characteristics refer to unbinned readout mode.
| Parameter | Slit-Viewing Guider |
Offset Guider |
|---|---|---|
| Camera Head | Photometrics CH250 | Photometrics CH250 |
| Camera Electronics | Photometrics CE200 | Photometrics CE200 |
| Camera Controller | Photometrics CC200 | Photometrics CC200 |
| Detector | Thomson 7863 CCD | Thomson 7863 CCD |
| Detector Type | Front-side illuminated | Front-side illuminated |
| Detector Cooling | Thermoelectric with glycol heat exchanger | Thermoelectric with glycol heat exchanger |
| Inverse Gain | 1.66 e-/ADU | |
| Readnoise* | 146 e- | |
| Detector Size | 384 × 288 px | 384 × 288 px |
| Pixel size | 23 µm | 23 µm |
| Pixel scale | 0.239 arcsec/px | 0.213 arcsec/px |
| Field of view | 91.8 × 68.8 arcsec | 82.6 × 61.3 arcsec |
| Sensitivity Limit (unfiltered) | TBD | TBD |
| Orientation for SKYPA=0 | North right, East up | North right, East up |
| Filters | See table below | See table below |
| Focal Plane Coordinates of Camera Center | X=7.33 mm Y=-260.47 mm |
X=-241 mm -219<Y<-309 mm |
| LRIS pixel coordinates of camera center | N/A | |
| Usable modes | Longslit spectroscopy Multislit spectroscopy** |
Longslit spectroscopy Multislit spectroscopy Direct imaging |
| Effective Date | 02-Jul-1999 |
As of March 2001, the two LRIS guide cameras have identfical filter complements, as specified in the tables below. To insert a particular filter, use the modify (m) command in conjunction with the appropriate keyword name (tv1filt for the offset guider and tv2filt for the slit-viewing guider) and filter position number to select the filter.
| Guider | Offset (Movable) | Slit-viewing (Fixed) |
|---|---|---|
| Keyword | tv1filt | tv2filt |
| Filter 1 | Clear glass | Clear glass |
| Filter 2 | B | B |
| Filter 3 | V | V |
| Filter 4 | R | R |
For example, to select the V filter on the offset guider, you would type the following command at the shell prompt on lrisserver:
lrisserver{lris1}: m tv1filt=3
If the computer believes that a certain filter is inserted,
requesting that filter again will have no effect. Hence, if you
believe the wrong filter is in place, move to another filter and
then back to the desired filter. For example, to ensure that
the clear filter is in position on the slit-viewing guider:
lrisserver{lris1}: m tv2filt=2
lrisserver{lris1}: m tv2filt=1