Model 617A Reflective Condensing System / Focusing Accessory is useful for coupling broadband light sources to McPherson monochromators. It uses 2 reflective optics to focus a source to the entrance slit, usually 1:1. The reflective system eliminates chromatic aberration, provides maximum spectral range, and does not require refocusing. An aperture is provided to match f/nos. McPherson accessory light chopper and filter wheels fit inside this housing next to the slit. Works with most McPherson sources and fiber accessories.