Digital Projector Calibration

A small but technically and visually astute group (eh?) took on the serious objective of eliminating the guesswork from setting up the digital equipment to project a consistently perfect image on Thursday 6th December 2007. The meeting to properly calibrate the Canon SX60 and Shuttle took place at 53 Cavendish Rd. Previously both our projectors Standard default settings had been tweaked to generate saturation, contrast and colours which appeared to match what the author expected. This method would clearly be seen as too unscientific if it came to convincing external contributors to our inter-club competitions that their image hadn’t lost a mark as a result of our imperfect projection quality.

To standardise our method (and bearing in mind that other organisations may wish to follow the procedure), we used a readily available and widely acknowledged professional calibration kit the Spyder 2 Pro. The latest software update was downloaded from the ColourVision website (version 2.3.5) onto the Shuttle. The equipment was arranged to project an image which accurately filled the large screen (using the projector’s Auto Set-up facility) in a completely dark room, the only ambient light being the small amount reflected from the neutral walls and ceiling. The projector’s default settings using sRGB mode were selected as recommended and from this point on no further manual settings would be made. Any adjustment to the projector’s output would in future be decided upon by the profile now to be installed on the Shuttle. The sensor was held, facing the screen, approximately one foot from the screen and the standard Spyder 2 Pro calibration procedure followed.

Following installation of the profile we were able to view the “before & after” results. Using a wide range of our well-known pictures, together with a number kindly supplied to us by Ed Roper of the L&CPU (and Wigan 10) we spent time casting a very critical eye over them. A projected test page and step wedge with white to black gradients, as supplied by Marrutt Digital Solutions, was also closely scrutinised. The consensus of opinion was that the new profile had added a subtle improvement, in that the saturation, contrast and colour looked to be as pleasingly accurate as we could imagine with detail retained in both highlights and shadows (subject to them having been present in the original of course).

Although conscious of the fact that a different screen and a different room could have a bearing on the perceived result we consoled ourselves in the knowledge that this has always been the case, be it for slides or any other projected image, and should prove to be negligible in practice. The group involved directly at this session were: Brian Turnbull, Bill Chadband (Exhibition Sec.) Barry Pearson (Competition Sec.) Roger Dye (President Elect) and Tony Redford (President) all of whom felt this had been a very satisfactory exercise. There will be a number of opportunities for the whole membership to view their own pictures over the coming weeks, and your feedback will, as always, be welcomed.

Tony Redford