Pin registered slides and multi-projectors alignment

Written by Paul Cordwell, UK :

Each projector has to be aligned with every other projector using a gradated image in a pin registered glass slide mount. The gradated images were produced on a rostrum camera. It had to be glass because the film could buckle very slightly and registration was lost. Even the brand new slides out of the box always need polishing and dusting. There was zero margin for error.

The projector staging was very substantial too, even so, unless something had seriously gone wrong the whole crew didn't move at all during the show, because even a cough could cause misalignment.

Also the Kodak SAV2020's projectors, the preferred choice of multi screen producers, had an automatic bulb swap, should one blow during the show. Most industrial presentations used 9 projectors, three banks of three to achieve a wide screen format. However, there were, 24, 49 and 96 projector set ups, a few of which I've worked on.

One of the companies I shot for won a prize at BAFTA. I often went to the shows, predominately because I was nervous about my work, and there's always something else to learn. Also working on installations gave a different perspective about how the images were used, which became fuel for the next shoot.

The pin reg shoots were always exceptionally stressful because in addition to all the normal photographic requirements, exposure depth of field etc, there was a script to follow, continuity, sequencing, and remembering to engage the pins which sometimes made shooting very laborious.

Shooting a sequence in the studio was no certainty because quite often one out of the six flash heads being used would not give the power required and the everything had to be re-shot. The cable as shown allows the motor drive to function on the F2 as the pins are removed. And even if you got it all correct sometimes errant E6 processing created re-shoots.

Things got really complicated when clients and agencies started asking for pin reg 3D photography. This employed a bracket to which the F2 was mounted, which racked left and right to accurately produce two slightly converging pin registered images that created the 3D effect. The angles set incrementally and the separation between each image was different for every lens and focus. It made the surveys for the shoot incredibly important to ensure all to different formulas were worked out with a calculator before the shoot started.

This medium was fabulous for car launches, where the products moved on screen using still photography, sometimes at 24 frames a second which was movie quality. Product build up shots were fantastic to work on, but it was necessary to be organised because one error or omission meant starting from the beginning. All the graphics for the shows were shot on a pin reg rostrum camera, the effects achieved were breathtaking, especially set to music. the track of choice then was Jean-Michel Jarre and Oxygen.

Clients loved multiscreen product reveals, ideal for still photography. Really happy days, from tools to perfume to furniture, cars, boats, trains and aeroplanes, we shot it all. After that video took over, I got a film cameraman's ticket and started shooting commercials, features and most enjoyably, pop promos all over the world.