How many Dimmer Channels ?
Sun, 22 June 2008, 07:35 pmDon Allen28 posts in thread
How many Dimmer Channels ?
Sun, 22 June 2008, 07:35 pmWith the offer of state funding in WA for amateur theatres, the decisions on what to apply for need researching and some professional advice is required to explain the theatre lighting requirements of amateur theatre groups.
One ideal "Square One" lighting design, (so called because if you put everything back to "square one" you will be able to provide good lighting for any basic production ) is to:
Divide the stage into the nine basic acting areas ie DSL, DSC, DSR, MSL, MSC, MSR, USL, USC, USR.
Allocate two key lights to each area (the McAndless method see lighting links, this takes you to 18 lights from the front. at 45 degrees to the centre of each acting area.
Allocate a back light to each acting area, directly behind the centre of each acting area, this takes another six channels
You now have an ideal lighting design that uses 24 dimmer channels for individual control of each light. In a usual amateur theatre situation, you will have to parallel lights if you have less dimmer channels.
You now need to allow three dimmer channels if you have a cyclorama and additional channels for specials, so the ideal number of channels takes you up to 36, which is three dimmer racks, of 12 channels each, with a channels capacity of 2400 watts.
Any questions ?
Sodium
Mon, 23 June 2008, 08:20 pmI like to use sodium when going for a late afternoon general yellow look. I find the long 'warm up' time to accurately reflects the gradual yellowing of the light as the sun goes down.
I have a problem though. How can you get them to dim??? As they are gaseous discharge lamps, they don't work on a standard variable voltage triac dimmer, such as the Jands.
I have been considering developing a variable frequency dimmer, using commercially available variable frequency motor drives. By using the Jands dimmer to lower the voltage, and at the same time increasing the frequency of the supply delivered to the lamp, the lamp is able to be dimmed to approx 30% of brightness before it shuts down.
I'm wondering if anyone has tried this before?
And to answer your previous question, yes I am in WA, and do most of my work at Melville Theatre. Ian Black and I both work for the same electrical contractor.