Olympus has published the third installment of its video series celebrating the 50th anniversary of its Pen cameras. The compact, cropped-format cameras evolved into the Pen-F, one of the smallest mass-market interchangeable lens cameras ever made. The site says there will be another installment next week but, with few milestone Pen series cameras left to cover, its layout appears to leave room for more videos. Coincidentally, Olympus has said there would be more news this summer about its Micro Four Thirds camera, a distinctly retro mockup of which has been shown at recent trade shows. Update: Olympus UK has told us there will be a public hands-on event in London on June 25th at a venue to be announced soon. We'll bring you more details as soon as we have them.