Ricoh (Pentax) filed a patent for a DSLR cameras focusing screen (JP 2018-151549): PROBLEM TO BE SOLVED: To provide a diffusing plate easy to see a subject image (real image) and a single lens reflex camera using the diffusing plate for a focusing screen. SOLUTION: In order to observe a real image through an eyepiece … Continue reading Ricoh (Pentax) filed a patent for a DSLR cameras focusing screen