The transmission values given here were read off by eye from spectrophotometer tracings (not made by me; I do not guarantee their accuracy). Dashes mean no readable values are available at the given wavelength. The BVRI filters were made according to the prescription given by Bessel (PASP 1990, 102, 1181), and are intended to transform well to the Johnson-Cousins system when used with CCDs. The Rs is the Spinrad night-sky suppression filter, discussed in detail by Djorgovskii (PASP, about 1982, I think). Note red leak comments at end of table. Angstroms B V R I Rs 3500 .01 3600 .02 3700 .09 3800 .25 3900 .40 4000 .51 4100 .58 4200 .63 4300 .66 4400 .66 4500 .63 4600 .58 4700 .47 .01 4800 .33 .02 4900 .19 .38 5000 .10 .79 5100 .04 .88 5200 .01 .88 5300 .85 5400 .79 .01 5500 .72 .02 5600 .61 .15 5700 .50 .47 5800 .37 .71 .01 5900 .24 .73 .03 6000 .15 .72 .15 6100 .09 .71 .55 6200 .05 .68 .74 6300 .02 .64 .79 6400 .59 .84 6500 .54 .01 .89 6600 .49 -- .89 6700 .44 -- .88 6800 .39 -- .89 6900 .34 -- .89 7000 .29 .02 .85 7100 .24 -- .75 7200 .21 -- .73 7300 .15 -- .84 7400 .12 -- .69 7500 .11 .68 .65 7600 -- -- -- 7700 -- -- -- 7800 -- -- .01 7900 -- -- -- **note change of wavelength scale here** 8000 .03 .85 8500 .83 9000 .79 9500 .75 10000 .66 10500 .45 11000 .25 11500 .07 12000 .02 Red Leak Second line below is approximate start of red leak in microns, third line is approximate peak strength of red leak on same scale as used in table above: B V R I Rs 1.4 1.4 (none 1.55 1.0 32 39 shown) 32 85 rem@ucolick.org 7 July 1994