Old Speed Graphics had two controls for the focal plane shutter. The first was a spring tension adjustment that determined how fast the fp shutter moved across the film plane. The second adjustment cranked into place fp shutter slits of differing widths. By combining different speeds of travel and different shutter slit widths, you had a continuously variable set of shutter speeds, the fastest being the narrow fp slit moving at the highest speed across the film plane. You set the combination based on the effect that you wanted, the brightness of the scene, film speed, etc.
At certain slit and speed combinations--most notably a narrow slit moving slowly in a vertical direction across the film plane, the forward lean of a moving subject resulted. I will visit Warren's web site and take a look at his train photo made with the fp shutter when I exit my e-mail. However, if you ever get a chance to see it, there is a TREMENDOUS action photo of a ca. 1910 automobile race made by Jacques Henri Lartigue and a camera with a focal plane shutter. He panned the race cars as they sped past his camera, but he panned a little too slowly and the cars moved past the camera. This resulted in the circular wheels being recorded as ovals leaning forward!!! Not only that, telephone poles and spectators in the background were recoded as leaning in the opposite direction as he quickly panned the camera across the sene. It looked as if the wind created by the fast-moving cars had blown them over!!! He did not intend to do this, it just happened as he panned the photo. I truly believe that this image gave rise to still-frame and motion picture cartoonists drawing circular car wheels as ovals to imply speed, and drawing telephone poles and fence posts as being blown backward as the fast car went by. I have a Xerox of this photo somewhere here, but it will take me 2 or 3 years to locate it. Anyone else out there have a copy of this photo that you could send to the SPORRS group as a file attachment? You gotta see this photo! I tried to duplicate these effects 25 years ago with my ancient wooden Speed Graphic, but never even came close. John B. Corns --> SPORRS: Serious Photographers of Railroad Related Subjects X-Mozilla-Status: 0011 Content-Length: 3015
