The Purchase of Sloan Filters for Use at MRO

 

In July of 2001 a set of Sloan Filters was purchased for use at the Manastash Ridge Observatory. These filters were purchased from Asahi Spectra Company, Ltd. in Japan. Our filters are square 50x50 mm with a uniform thickness of 5 mm. On average, these filters cost us about $770/filter. Their delivery was on time and with excellent documentation of the filter characteristics. A good contact person for the purchase of such filters is Mr. Toshihiko Kimura. He can be reached at the email address of:

t-kimura@asahi-spectra.co.jp

The following figures show the transmission curves for our Sloan filters as of 18 July, 2001.

Figure 1 . The u' band transmission curve. The central wavelength of this filter is approximately 353 nm and the FWHM bandpass is 62.5 nm. The peak transmission is 76%.

Figure 2. The g' band transmission curve. The central wavelength of this filter is approximately 486 nm and the FWHM bandpass is 152.7 nm. The peak transmission is 90%.

Figure 3. The r' band transmission curve. The central wavelength of this filter is approximately 626 nm and the FWHM bandpass is 134.2 nm. The peak transmission is 95.6%. Note the red-leak beyond 1130 nm. This leak is unimportant for CCD detectors.

Figure 4. The i' band transmission curve. The central wavelength of this filter is approximately 767 nm and and the FWHM bandpass is 133.3 nm. The peak transmission is 97%. Note that the red-leak beyond 1133 nm is unimportant for CCD detectors.

Figure 5. The z' band transmission curve. This is a long-pass filter with a cut-on wavelength of 835 nm.