Wanting to control bounce light is being discussed in the ControlBooth Lighting and Electrics forum; I will try to explain my task to the best of my ability, but without measurements and angles to reference, ...

1. Wanting to control bounce light

I will try to explain my task to the best of my ability, but without measurements and angles to reference, we'll have to speak theoretically and see if we can come up with a solution.

My "high ups" want me to light my speaker in a way such that there is a black "void" between them and the upstage-most wall (we use as a 'cyc-like' projection surface). Our Apron is 9 ft. deep (all speaking done from here), from plaster line to cyc is about 20 ft. ... not deep at all. Bounce light catches our hand drums, guitars on stands, avioms, etc and they would like for this to not happen. As the plot stands now, the Front Light for the Speaker is on the last electric, furthest from the stage, creating the shallowest angle in the house. My first thought is to increase the angle, minimizing the reach of the bounce light, but this is a huge amount of work for the results to be negligible. On top of that gamble, we are the host to our video venue and I do not want to create downward eye-shadows or that no-neck look for our speakers. It doesn't help that they just refinished our stage, granted to a darker color or wood, but nonetheless refinished and fairly shiny (no one wanted to listen to the Theatre guy that asked for a black floor!).

Suggestions?

2. Re: Wanting to control bounce light

You're first instinct is a good one, remember the angle of incident is the angle of reflection. You're other options are to not do straight on frontlight but to look at angled frontlight. I'd also be a fan of hanging one light for this situation and one for your "video venue"

3. Re: Wanting to control bounce light

Two factors in play here.
1. As said above, angle of incidence=angle of reflection. With a reflective floor, regardless of its color, you're going to get bounce on the backdrop.
2. Increasing the angle of elevation will move the reflection higher on the drop, but won't eliminate it. Angles less than 30° flatten and destroy revelation of form. Angles greater than 60° create problems with eye sockets, nose and chin shadows as noted. Hence the reason that McCandless guy decided a 45° vertical angle was the best compromise.

If the lecturn is center, I think Grog12's idea of using two lights separated horizontally by 90° is the best approach. The reflection then won't be directly upstage of the presenter and thus will not be in the camera shot. Also, get as many cretins as possible to scuff up and dull down the shiny floor. Late at night, when no one's looking, take take a floor buffer equipped with a steel-wool pad, to it.

Point of nomenclature:
Originally Posted by theILLUMINATEDfrog
...As the plot stands now, the Front Light for the Speaker is on the last electric, furthest from the stage, creating the shallowest angle in the house. ...
Electrics (horizontal mounting positions) are typically numbered beginning at the plaster line and moving upstage--thus the "last electric" would be the one nearest the cyc or back wall. Mounting positions DS of the PL are numbered starting with the one nearest the plaster line and moving toward the rear of the audience, and are usually referred to as FOH#1, FOH#2, and so on.

4. The Following User Says Thank You to derekleffew For This Useful Post:

Les (August 16th, 2010)

5. Re: Wanting to control bounce light

The Lectern is on stage left but our speaker (an emphatic methodist preacher) moves like a caged and hungry lion, back and forth, so "the shot" is essentially everything we have on stage. And I just might be the next one crucified if I mess up that brand new floor.

6. Re: Wanting to control bounce light

So are they essentially wanting a black background? If that's the case, I don't think it will happen with a white cyc/projection screen back there. It will catch any and all light in the place and throw it right back at you. Heck, I can see a cyc in a near dark theatre from the rear of the house.

7. Re: Wanting to control bounce light

What about reasonably high sidelight from both sides? I've often done this for conductor specials when you're quite heavily restricted by not being able to get light in the conductor or orchestra members' eyes, and it works pretty well. You might need a few of them, focused across your stage, but you may very well be able to create a "strip" of light with the bounce going to the side rather than upstage - but you shouldn't lose eyes or get funny shadows.

8. Re: Wanting to control bounce light

Since the topic of changing the angle of light and lighting postitions has been covered, let's move into other ways to fix your problem.
Is there any way you can lay down a runner? A strip of carpet that can be rolled up and put away for some events, but rolled out as a set peice for speaking events? A carpet will absorb your light better than your shiny floor.

Option # 2 would be to change your backdrop. If they really want black, can you hang a black curtain?

If a carpet or black curtains are not an option, and changing the angle of front light does not decrease your bouce light, then your answer would be to light the cyc so that you don't see the bounce. Throw some cheap LED pars on the floor in a pretty color, or a light with a some kind of break-up gobo. Anything that you would rather have your audience looking at rather than bounce or bleeding light. Try fixing the bounce first and if that doensn't work then hide or overpower the bounce.

Kenneth Pogin
Production / Tour Manager
Minnesota Ballet

9. Re: Wanting to control bounce light

Odds are that in real life (i.e. to a person sitting in the venue) you will never create a true black void between the speaker and the cyc. Even if you covered the floor with black velour, you would still get reflection and spill (though not nearly as much). This is just the nature of the beast. You can get close, and all the suggestions that have been given are the same as what I would suggest.

However, if the goal is to create a black void for video, that should be a little easier. Consider that a video camera does not "see" the same dynamic range that the human eye does. A camera sees a much narrower range. Ironically, this means that if you were to make the area where your speaker stands/wanders brighter, it would make the background appear darker to the camera. Thus, if you bring the speaker as far downstage as possible and light the heck out of that spot, it should force the shadows (darkness behind the speaker) to go black in the camera. This is the reason that on film and TV sets they light the crap out of everything, even in dark scenes, because the difference between light and dark for the camera is so much less than for the human eye.

10. Re: Wanting to control bounce light

Excellent idea Alex as with the rest. Some things possibly to add if of help to the above.

First, real Velour is much more light absorbing than common Commando Cloth or Duveyne. Any chance of putting one's money where one's mouth is in requesting the spill light go away? Also, the lighter the color, the less it will show the lighting on it, any chance of say changing the color of the background drape? Red for instance would make it easier but of course is a totally different ball game for the lighting and presentation expectations.

McCandless is a Method and somewhat negotiable for need in exact angles. Yea, it's probably best when used but cheating some is also possible. Don't forget the top rear light in doing it either. For the camera also (though I lack experience in this field, should you do warm/cool left/right sides, don't get too drastic if at all.)

As with Les's idea, fight light with light, is it possible to light the black rear curtain in say lighting it's blackness up and fighting the spill? Might grey tone some and have to work on the frosted wash so as to have an even effect, but light fighting light should eliminate the spill.

Next option perhaps is about frosting verses output and bouncy bouncy of the talent. Obviously irising down to the talent would be ideal, but perhaps in fighting spill of that spot lighting from the front the entire surface of the drape and area might be a better option. Otherwise assuming a needed intensity from throw length and angle, possible to lamp up to a higher wattage what's lighting the podium and frost the heck out of it in not having an effect on the back drape?

As with cameras having the different type of eye, also the camera when focused on the speaker is not going to be showing the entire stage. If camera angle can be fairly similar to angle of projection of light on the speaker its mostly a moot point if the area of spill is within the area of coverage by the spotlight. Don't forget some uplighting though - just a minute amount of it though. Will help a lot.

Final note (never did this before) and liking Icewolf08's and others ideas, and that of the carpet on the loor to absorb, perhaps plan a bit of extra time to prep this thing. Look at the camera view and adjust long before the production. Have say 8' side arms ready to go as with some booms and extra fixtures and frosted gel ready to go perhaps. Better to go in heavy than have to scramble.