I try to improve this site while benefitting from what I learn, notably during my explorations on Internet.I will note here the addresses of the sites where I made loans. The Japanese or Russian sites were translated thanks to the Google linguistic tools.
A big thank you to Jean Louis PRINCELLE and his "The authentic guide to Russian and Soviet Cameras", ie my Bible, always at hand (I have sometimes found some inaccuracies, but I had Internet and www.zenitcamera.com to help me).
Logos: www.zenitcamera.com/qa/qa-logoshttp://cccpcamera.photo-web.cc/RussianCamera/Kaisetsu/FACTORY/FACTORY.htmlLenses: www.zenitcamera.com/catalog/lenseslist.html(I borrowed there the most part of optical schemes)www.photohistory.ruHistory of brand names: www.zenitcamera.com/archive/history/marks.html
A wealth of information for the amateurs of Praktica:www.praktica-collector.de
Essential, but unfortunately disappeared:The Sub Club (www.subclub.org)
Make do with:Submin.com
Essential too:Asahi Optical Historical Club
This site was initially written in Flash thanks to Cariboost (now WebAcappella). It is now written in HTML5-CSS3, a huge thank to Mathieu Nebra, his tutorial on OpenClassRooms is absolutely perfect!