Just a thought.. That darkslide is weird and not needed unless you intent on taking off the back all the time ..and microspcopes don't have a shutter... (hence the use of adapters and normal SLR backs)... BUT... I was just editing the Konica I page on Camerapedia and saw that the Rubicon (the 1940s predecessor of the Konica I) was made as a camera back for x-ray photography (on 35mm film)....with the darkslide as shutter...