Need recommendations for auditorium stage lights

I

Imamacuser

Veteran
My church is thinking about getting a PTZ camera and installing some stage lights, and I was hoping people here could give me some pointers and check my methodology.


The primary use case is to illuminate the center stage area for the speaker and music team, and the secondary use case is to illuminate the whole width of the stage for the choir & drama events.

There’s a projector screen on the back wall starting at about 5.5’ off the floor, so I need to look at lights with beam angels and modifiers that won’t spill onto the screen.

The lights will be controlled with a DMX board in the back of the sanctuary.

I still need to decide on a color temperature, as there’s tons of ambient light from windows, but the ceiling lights are a mixture of warmer color temperatures.


I haven’t been given a target budget, but I’m looking at the best bang for the buck options, as this application doesn’t warrant Arri lights.


Stage dimensions:

9’ deep (approximately)

Can't remember the width offhand.


Measurements:
  • Distance from light to subject = 29.83-ft.
  • Ambient light meter reading for typical Sunday service = f/1.0 at 1/60th of a second shutter speed.

Calculations:
  • Target lens maximum aperture = f/5.6
  • Assuming a base ISO of 100, I need +5 EV of light to attain proper exposure at f/5.6.
  • 5 EV converted = 7.43224 Foot-candles or 80 LUX
  • Factoring the inverse Square law to determine falloff over distance = 6689.0189 Foot-candles or 72000 LUX

Questions:
  1. How do I determine the base gain/ISO of a PTZ camera (I started out in photography, so I think in terms of ISO rather than gain)? The Canon CR-N300 specs list the gain as 6 to 33 dB, but what is the equivalent ISO to 6 dB, 50, 100, 200, 800?
  2. Is there an online calculator that simplifies things? I used this online table to make the stated conversions.
  3. What type of lighting fixtures should I be looking at? I’m not familiar with stage lighting, but have run across PAR cans, floods, and spots with focusing lenses.
 
First off I don't know where you got a base sensitivity of 100 ISO from. Cameras are far more sensitive than this these days. I would start at 400 ISO. I also don't know why you need a T5.6 aperture as that is very slow. T2.8 is likely enough but even to be safe you could go to T4. I don't follow your exposure calculations because ISO 400 at T4 requires 800 footcandles or about 8600 lux. A far cry from your 72000, which would be extremely bright and uncomfortable in your church.

For your lighting I suggest a mix of COB LED lights with various lens attachments. I highly suggest that these days you want to use bicolor lights at a minimum but ideally some form of RGB color tunable light. Full disclosure -- I work for a lighting manufacturer of RGB technology lights, but I would make this recommendation anyway. You want the flexibility to adjust the color of the lighting for day or night use and will regret not doing so. If you just wish to illuminate than bicolor is likely fine for your purpose but if you wish to artistically use color in any way than you should definitely consider some RGB type lighting. There are three basic types of RGB lights: basic RGB which is good only for backgrounds & effects as they do not have a complete color spectrum so look bad on people, RGBW which mixes in white light and is mainly used for standard white light illumination with a little color adjustment range included, and RGBACL which uses the multiple colors to give great white light while allowing the most flexibility in color. As these lights get more complex the increase in cost but also increase in flexibility and usefulness.

A COB LED light is an open face hard light. They all come with reflector dishes to be hard, somewhat directional lights, but the lights used in this way are quite harsh and unflattering. There are two main optical attachments you could use instead. The first is a fresnel lens which is an adjustable beam focusing lens that has a slightly soft quality while remaining directional and roughly controllable. It can be used with barndoors to help control the beam and prevent spill on the projection screen. I would suggest fresnel lenses as your primary solution for this. The other optical solution is a projector, which generally come with either a fixed lens or interchangeable prime (not zoom) lenses. These are very precise beam optics which can use internal shutters or cutout frame "gobos" to shape the light or project patterns onto surfaces. This would be the most precise way to control your lights.

The manufacturers all have the photometrics of their lights available on their websites. The big task is that your lights are so far from the stage at nearly 30' (most lighting specs are given in meters so I would use 10m). You would need multiple smaller lights or a few very powerful ones to properly illuminate from that great a distance. My company Prolycht makes the Orion 675 FS and the Orion 300 FS lights, and while the 675 could easily provide that much illumination with its fresnel set to even the widest beam angle, the 300 would need to be focused in some to be bright enough. That means you'll need a bunch of lights to provide the coverage and illumination.

At this point I should say that you're really best off hiring an integration company that specializes in such work. There are a number who do a lot of work with churches and understand the needs, and can also help with the installation and implementation. I'd be happy to suggest some but would also say that many churches belong to affiliated groups of churches and I know that there's a lot of suggestions within these groups.

For me to make specific suggestions beyond this is quite difficult. Usually such work involves a lighting plot, stage layout and site visit. There's a lot of ways to do this and a bunch of factors that need consideration. This is where an integrator is helpful so you don't spend good money after bad.
 
At this point I should say that you're really best off hiring an integration company that specializes in such work. There are a number who do a lot of work with churches and understand the needs, and can also help with the installation and implementation.
Click to expand...

Thats what I was thinking as well, Mitch. Barbizon is a good one, but I’m not sure where Imamacuser is located.
 
100 ISO is a guess, as I can't figure out the base sensitivity of the PTZ camera.

PTZ cameras have variable aperture lenses, e.g. the aperture diaphragm stops down to f/5.6 as the lens zooms in.

I used the conversion charts on the Draco Broadcast site to arrive at my calculations, and the calculator academy Inverse Square Law calculator to compensate for falloff over distance. I'm open to a better method if you have any suggestions.

My church is a little NW of Des Moines IA.

My day job is as an AV Tech (basically the AV equivalent to desktop support IT), and in the course of my job, I have either coordinated with the local AV integration companies on installs or dealt with the systems they installed, and they have often proved to be incompetent, and in some cases charlatans, so I'm reticent to use a local integrator.
 
I would suggest assuming that the base iso as far as maximum dynamic range is probably 400 iso. I have ran Canon XF605's with Canon PTZ cameras and the PTZ's have no problem matching the XF605's at 500 ISO and f/5.6. In fact, that seems to be where most of the events I shoot are lit for. Maybe even a stop or two lower. I would just take a standard indoor event level lighting output and let that be your baseline. The cameras will be able to keep up.
 
If you believe your local integrators are not up to snuff than I suggest working with a more substantial service provider such as Sweetwater in Wisconsin.

Your calculations don't make sense because you were calculating the wrong things. The first number you need to determine is the brightness level you need on stage. If you go with 400ISO and T5.6 (which I still say is quite high and you should consider better PTZ cameras from Panasonic or Canon), then the normal exposure illumination level would be 800 footcandles / 8600 LUX.

Before you calculate what lighting is required to achieve that illumination, you need to design the lighting. Should there be bright areas that separate from other parts of the stage, such as at a podium or pulpit? What about some side lighting and backlighting in addition to frontal? There's a music performance area which needs consideration and that is separate from lighting the full stage for a choir.

It's VERY easy to blow through $100K on the lighting design of a small church without knowing what you want it to look like. And that's for the lights -- don't forget about what it will take to rig all that stuff on ceiling truss, run power & DMX and install a lighting board. And just how are these PTZs being controlled? They need to be mounted and feeds run to a control room or station with switcher, monitors, graphics board, streaming encoder, etc. And the audio mix needs to be separate for any recording or video stream to the house PA, so that's an audio console as well. I don't know the size of your church but is there a plan for IMAG (a big monitor so people at a distance can see what's happening on stage)? That's more gear to consider, including placement so the lighting doesn't interfere.

I really wouldn't half-ass this. This is why good integrators exist. If you don't like the local ones call Sweetwater. Or Texas Media Systems, Omega Broadcast, AbelCine, Midwest AV, or even The Studio at B&H (their inhouse integrator boutique). You will be FAR better off than doing this yourself.
 
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