Filters - 01/04/03



The relative throughput of MegaPrime versus CFH12K in its current environment, with the current BVRIz' filters.
No U on CFH12K, and a big overlap between I and z'.



Same thing (without 12K and MegaCam QE), this time with the SDSS filter set.
u' is poor in shape compared to the other filters.



A possible new u' filter for MegaPrime. The lower and upper cuts can be easily changed without modifying the overall transmission characteristics of the filter.


SDSS u', g', r', i', z' filters

NAME  CENTER(nm)  FWHM(nm) TMAX(%) DIMENSIONS(mm)  TRACE      
--------------------------------------------------------------
u'       350       600     0.778    76x76x3         N/A       
g'       480       140     0.919    76x76x3         N/A      
r'       625       140     0.976    76x76x3         N/A      
i'       770       150     0.987    76x76x3         N/A      
z'       910       120     0.980    76x76x3         N/A
Note: SITe CCDs are not sensitive to the "Red leak".

u', g', r', i', z' combined trace
 
 
Filters effective wavelength full width at half maximum Wavelength range limiting magnitude for S/N 5:1
u' 3540 570 3250-3800 22.3
g' 4770 1370 4085-5455 23.3
r' 6230 1370 5550-6915 23.1
i' 7630 1530 6850-8400 22.5
z' 9130 950 8650-9600 20.8

Table 1: filter characteristics of the SDSS.