You are in: Instruments > AcqCam > Performance and Use > AcqCam Components > Filters

Acquisition Camera Filters

The Acquisition Camera contains two filter wheels whose details are summarised here. Although similar to the standard UBVRI filters, some photometric differences might be expected and users are cautioned for those programs that depend on direct comparison with previous observations. We are establishing empirical transformations between the Acquisition Camera instrumental magnitudes and the Johnson-Kron-Cousins system as part of the calibration process (details to follow).

The wavelength interval given in the tables in the interval within which the transmission is larger than 50%. If transmission graphs or data are available, click on the "data" or "plot" label in the tables below to retrieve them. The sky brightness in these filters as a function of lunar phase is given as part of a description of observing condition constraints.

Color Filters

Gemini filter Number	Filter name	Wavelength Interval (nm)	Transmission curve	Instrument	Notes
G0101	U_G0101	-		AcqCam-N	(1)
G0102	B_G0102	-		AcqCam-N
G0103	V_G0103	495 - 625	data, plot	AcqCam-N
G0104	R_G0104	605 - 750	data, plot	AcqCam-N
G0105	I_G0105	725 - 1000+	data, plot	AcqCam-N

G0151	U_G0151	355 - 395	data, plot	AcqCam-S	(1)
G0152	B_G0152	370 - 480	data, plot	AcqCam-S
G0153	V_G0153	495 - 630	data, plot	AcqCam-S
G0154	R_G0154	610 - 750	data, plot	AcqCam-S
G0155	I_G0155	720 - 1040	data, plot	AcqCam-S

Neutral density Filters

Gemini filter number	Filter name	Average Transmission	Transmission Curve	Instrument	Notes
G0156	ND001_G0156	0.01%	data, plot	AcqCam-S	(2)
G0157	ND01_G0157	0.1%	data, plot	AcqCam-S	(2)
G0158	ND1_G0158	1%	data, plot	AcqCam-S	(2)
G0159	ND25_G0159	25%	data, plot	AcqCam-S

Notes to the table:
(1) Optical path difference (OPD) compensation for the U-band filter is to be determined. The neutral density filters cannot be used with the U filter because they have no transmission within the U passband.
(2) These neutral density filters are yet to be delivered.

Last update February 16, 2002; Cláudia Winge
In original form February 28, 2001; Phil Puxley