What lights to use for backlighting?

[DonAllen]

The use of backlight is most effective when the audience does not see the source of light. The fresnels with barn doors are most practical or the par cans if they have a long nose or snoot. Having the backlight directly behind the actors will provide the best silhuette effect, which will make the followspot on the single performer more effective. Strand Lighting put out a free guide to Lighting The Amateur Stage as part of their Tabs magazine http://www.theatrecrafts.com/archive/documents/lighting_the_amateur_stage_1.pdf . Page 6 has a useful guide to what the various angles do. Remember that very little light will be reflected off the top of the actors shoulders and head, so it needs to be a bright light. There will be a lot of bounce off the stage floor towards the audience.

 

[DELO72]

For a true silhouette effect, you want to light a surface behind them (like a cyc) and leave them completely unlit in front of it. If that isn't an option, then the Fresnels or S4 PARs would both be fine options from a high back angle, but it won't really cause the silhouette that I think you are looking for. Try them at very dim settings and play with the contrast to see what you can achieve. Also- you could play with different ends of the visible spectrum to mess with the eyes of the audience and try to achieve some separation that way? Maybe a saturated Blue top light/backlight and a dim red side light. The eye's wanting to focus on those colors in different ways (areas of the retina) might cause a fun effect.

 

[Painterspoon]

@Painterspoon You've mentioned you have 60 dimmers, here are a few more queries which would be useful for you to answer and would permit many of us to more easily and quickly answer some of your questions:
- What is the rating of your dimmers, how many Watts per dimmer?
- Are all of your dimmers identical, the same make, model and wattage rating?
- How are your dimmers housed; possibly 1 rack containing all 60, 2 racks of 30 each, 2 x 24 + 1 x 12. Maybe 5 x 12 per pack, maybe even 15 x 4 per pack?
- The manufacturer of your dimmers is considerably less important to know but none the less useful. In Canada they could be Strand, Strand Century, Century Strand, ETC, or any of a myriad of other brands and models.
- Where are your dimmers located? Possibly overhead on your grid, or in an adjacent room SL, SR or US? Maybe even in your FOH booth?
- Do the load circuits from your dimmers pass through what is commonly referred to as a "Hard Patch", a cross patching facility which patches the actual output voltage and current of your dimmers?
- How does your control board connect to your dimmers? Possibilities: Hard wired, plug connected, via analogue utilizing one conductor per dimmer in a cable, via AMX, DMX or some other control protocol?
- What make and model of control board do you have?
- Where is your control board located; possibly in an FOH booth, on a table at the rear of your audience, maybe back stage somewhere?
- Do you only have one location for your control board or are you able to relocate to various locations while hanging and focusing Vs. rehearsing Vs. performing?
- Does your control board (or control console if you prefer) include a feature commonly referred to as a 'soft patch' which allows your various dimmers to be controlled by various control channels ranging from 60 channels controlling your 60 dimmers on a one to one basis all the way to one single control channel controlling all 60 dimmers simultaneously?
- Does your controller include manual sub-masters?
- Does your controller include "Groups"? (Groups are effectively sub-masters without physical sliders.)
P.S.: Thinking of your Chauvet PAR64 LED's; You'll likely also learn from their owner's manual that they may be operated (Without modification) from a variety of line voltages and frequencies thus identical models may be sold and easily successfully powered world wide. If you read your manual closely you can likely daisy-chain even more fixtures if you have a higher line voltage available: In Peterborough, Ontario, Canada you'll likely have voltages of 120, 208 and possibly 240 volts available. You MAY also have 347 and 600 volts available fairly conveniently but I'd strongly suggest you DO NOT entertain utilizing line voltages nominally higher than 208 and 240 volts.
This, to me at least, feels like enough keyboard bashing for the nonce; Back to you Missy Spoon @Painterspoon
Edited to insert a closing bracket I'd inadvertently omitted.
Toodleoo!
Ron Hebbard

These are all really good questions which I unfortunately don't have the capacity to answer at this moment. Had a great day taking students to see Come From Away in Toronto today - go see it if you haven't! Lighting was spectacular

 

[kicknargel]

can I use an extension cord with a couple of inputs as a twofer, in case I run out of channels right where these lights need to go?

Need to point out that per code (NEC) regular, store-bought extension cords are not OK to use in any theatre lighting scenario. There are a couple factors. One is the durability of the jacket and another is the electrical capacity of the wire itself. The first doesn't cause immediate problems, it's a long-term risk factor. However if you try to pull too much power through an undersized cable, there's an immediate fire risk.

Now, if you're plugging into your dimmers, you can make some assumptions. It's a pretty safe bet that the dimmers are rated for 2400 watts each. To check, look at the breaker switch on each dimmer. 20 amps is 2400 watts (120v x 20a = 2400w). To not push it, 2000 watts is a good limit. So if your two lights total less than 2000 watts (likely) you should be OK to put them on one dimmer. But go to a theatrical supplier to buy or rent the proper cable and twofer.

 

[RonHebbard]

Yeah, totally! There's more than one way to skin a cat - I'm learning how to express myself clearly as a lot of this stuff is still new lingo for me. I appreciate everyone's patience! Great place to be. Every time I'm at school and run into something I'm not sure about, I know that I can post a question on here and get a host of great answers and ideas that get me excited to move forward. Much appreciated, always.

@Painterspoon How did you light your 'Cabaret' scene, were you happy with the look and would you do it the same way again?
Toodleoo!
Ron Hebbard