The exterior coating on the Tau, Tau2, Quark, and Quark2 front lens is designed to be salt/fog tolerant and sand/dust tolerant. All default configurations of Tau and Quark lenses come with a ‘hard carbon coating’ which is one of the most resistant coatings in the industry for LWIR lenses. If the Tau or Quark lens becomes noticeably dirty, then a light dusting of air should be enough to dislodge any dust particles (although small amounts of dust will not noticeably affect image quality). If the lens is still noticeably dirty, then the lens should be cleaned according to the following procedure: use 75% isopropyl alcohol and lens tissue, and use light wiping motions. Use a fresh section of tissue with each swipe so as not to drag dust or dirt particles back over the lens surface.For all legacy Photon cameras:
Legacy Photon cameras used germanium optics. The anti-reflection coating on these optics is easily scratched. If it is absolutely necessary to clean the lens surface, use the same procedure as above — 75% isopropyl alcohol and lens tissue, and use extremely light wiping motions. Use a fresh section of tissue with each swipe so as not to drag dust or dirt particles back over the lens surface.