Lighting : Lighting June 2014 - Vol 34 Issue 3
28 LIGHTING MAGAZINE | June/July 2014 CASE STUDY THE BRIEF Lecture theatres have come a long way in 30 years, when the Hugh Mackenzie Lecture Theatres were built multimedia meant an overhead or slide projector. Now almost every lecture involves a combination of PowerPoint and YouTube. Lecturers bring their own laptops with their notes and students bring tablets to take them. Universities are expected to have equipment suitable for the professions they teach and cater for a wide range of accessibility needs. In the refit of the first three of five lecture theatres in the Hugh Mackenzie block at Victoria University all these considerations were taken into account, however for the fourth lecture theatre an additional requirement was added, this would be the primary lecture theatre for the Media Studies department and so would have as much of the THX specifications included as practical to make it into a movie theatre without compromising its main use for delivering lectures. For this design I incorporated design principles for lecture theatres with my experience in design of theatrical (stage) lighting and lighting for movie theatres. In planning the fit out of the first of these lecture theatres the first issue I had dealt with was the mutually exclusive nature of the various requirements. For example the Universities brief required that for optimal projection of presentations the screen should have no more than 35 lux but for reading and taking notes the presenter and students should have 300 lux on their work area. Since using very dark colours everywhere was not an acceptable option it was important to let the client know about the conflict and find a solution. Scenes for the lecture theatres were developed and the requirements were assigned to specific scenes, for example the maximum light level on the projection screen is achieved for the ‘AV’ scene while on the desks By Michael Warwick, BBSC, TECH IES Lecture Theatre, Movie Theatre the light level targeted was lower than the overall brief, however in the ‘present’ scene the lighting on the desks was at the target level of 300 lux while the light level on the screen was higher than the optimal level. We also worked closely with the architects and through modelling identified the surfaces that had the highest levels of light reflection towards the screen, for this reason the back wall was a dark brown of about 15% reflectance and the side walls at the front were a textured concrete grey finish with a reflectance of about 30%. The flooring was also selected in dark colours. MOVIES In the ‘Movie’ scene the lights are not simply all turned off. While this would seem the obvious solution to creating a dark environment other considerations were the potential for students to arrive late or leave early and the requirement that the doors have a vision panel. While people coming and going is not ideal it does happen so step lights were installed under the tread, these are dimmable and DALI controlled as with all of the room lighting. In the Movie mode they are as low as the controller would allow. The vision panel in the doors at the front meant that there would be spill light from lobby and, once your eyes had adjusted to the darkness, a glare issue. The glare problem is accentuated by the fact that the doors are just to the side of the screen and so are in the part of the field of view most sensitive to brightness. To minimise the glare the lights in the entry are kept on, again dimmed down to a very low level. The effect is to reduce the light contrast and therefore glare. June/July 2014 | LIGHTING MAGAZINE 29 RIGHT: Step lighting for ease of access. WHAT IS THX? THX is a certification for movie theatres, instigated by Lucasfilm for the release of Star Wars VI its aim was to align movie theatre experiences for patrons. Primarily dealing with acoustic issues and picture quality, it also touches on lighting. The lighting section is descriptive, no specific levels are prescribed. The main guideline for lighting is that it should dim before the feature starts and lighting of the steps and egress should remain on.
Lighting April 2014 - Vol 34 Issue 2
Lighting August 2014 - Vol34 Issue 4