Anti-reflection

It took me relatively long time to finish the measure onto DIY extension tubes for Canon EOS system applying  anti-reflection construction utilizing flocking Non-Reflective cloth yesterday. Considerably strong reflection light noise was observed on internal barrel concave surface as shown, it is a matter for no neglect. All the lens and camera production makers are exerting themselves in researching in eliminating the harmful barrel internal reflections before  prior to the releases. Inconvenient reflecting phenomena occurs not only on the barrel internal surfaces but also on lens element, on shiny bayonet mount rear surface, on helicoid thread waving grooves, body mirror box and also on image sensor surface. Any measures for this unacceptable phenomena for the users should be done with some definite efforts if some clear and fine imaging results are desired. Consequently, did I apply some pieces of Non-reflective flocking cloth inside walls of EOS extension tubes following the concept that any factory designers do on their products.