Properties of Ly alpha z=8.2 filter (+PK50), measured by TRG on Feb 2, 2004       

Center: 1.1232um 
FWHM:   0.0092um 

Absolute Transmission at center: ~55%  (~67% of J order-sorting filter at 1.12um, 
which has a measured transmission of 84% at 1.12um)


trans*    wavelengths            OH contamination


50%   1.1186um and 1.1278um     none
10%   1.1168um and 1.1306um     weak lines near 1.1300
 3%   1.111 um and 1.136 um     weak lines at 1.1140, 1.1156, 1.1323;
                                med lines at 1.131,1.133, 1.135 
 1%   1.07um   and 1.18um       many OH lines

*relative to peak transmission 


No sign of significant long wavelength leaks.