Optical sight having an unpowered reticle illumination source

An optical sight comprising

• an optical train having an optical path therethrough;
• a reticle coincident with the optical path;
• and
• an unpowered reticle illumination source comprising
• an ambient-light receiver,
• a light filter positioned so that ambient light entering the ambient-light receiver is incident upon the light filter and the light filter transmits filtered light,
• a light-gathering prism that receives the filtered light and has a diffusing surface disposed to illuminate the reticle using reflected filtered light, and
• an unpowered light source positioned to emit light through the diffusing surface to be incident upon the reticle.

An optical sight comprising

• an optical train having an optical path therethrough, wherein the optical train comprises
• an optically powered objective having at least one objective lens, and
• an optically powered eyepiece having at least one eyepiece lens;
• a reticle coincident with the optical path;
• and
• an unpowered reticle illumination source comprising
• an ambient-light receiver,
• a light filter positioned so that ambient light entering the ambient-light receiver is incident upon the light filter and the light filter transmits filtered light,
• a light-gathering prism that receives the filtered light and has a diffusing surface disposed to illuminate the reticle using filtered light, and
• an unpowered tritium light source positioned to emit light through the diffusing surface to be incident upon the reticle.