# Candy Questions in Tech 11



## ship (Jun 24, 2005)

Special project candy questions: Explain the following, provide photos if possible, what specific piece of equipment is thought of (where possible with a weblink to the equipment website) and how to without damage to the fixtures any or all of the following:

1) Explain how to mount and make a follow spot into a gobo pattern projector. Where would it go? Explain hot to make my glass gobo of an astronaut on the moon bounce on the surface and approach me when projected on a screen.

2) Explain how to make a GoFres. How far away would you need to be to project onto a 12' square screen?

3) Explain how to make a Linnebach scene projector, give a example of a fixture and lamp type that’s optimum for doing it and a few ways to design the scenery so as best to take advantage of it or them.

4) Explain what a Miller Lamphouse or Stove Pipe Lamphouse or Shadow Projector is and how it works. What use might it have for a show.

5) What’s a moon beam and how does it get rigged?

6) How would one make a 6" Fresnel into a beam projector?

7) Explain how to do a dimmed shutter to out effect on a followspot without a dimmer.

8) Explain what would be necessary to change in order to mount a Color Kenitics MR-16 LED color changing lamp into a Leko - yet have it optically efficient still.

9) Say you want a wider field angle from a 3" Fresnel, would installing say a 60degree MR-16 lamp inside the fixture ½" away from the lens increase, decrease or remain the same the spread of the Inkie?

10) If you were to install a 8" Fresnel lens at the gel frame clip of a standard PAR 64 fixture, what would the effects of the various lamps have on it? Change that to a 8x9 lens than what would be the beam like with it?

11) Given a 4.1/2x6.1/2 lens sitting on a table convex side down, how far off the table is the flat surface of the lens? (This is an important formula to note by the way.)

12) Explain the Fortuny Indirect Lighting System and it’s use on a plaster cyc or in general. Given a light source too bright to gel economically, is this a feasible alternative?

13) Explain how on a dark stage, set up for a box set parlor scene how to keep it invisible, yet have someone walk to the center of the stage and have the actor perfectly glowing in light. No spill.

14) Explain how a ripple machine works and how to make one out of a single cell cyc. What applications might it have?

15) What’s a cloud machine and what would be necessary to make one of your own? Also what major caution is there to it’s use given what you can very about the cloud machine.

16) Given a sodium vapor light fixture, is it possible for a 16 show production or how effective would it be to gel it for a night scene Rx80 wash light? Given an arc source architectural type wash light or street light, what would be the most effective for projecting a deep blue light beam. Which will be most similar to incandescent source of light, or what might be the expected differences as important to consider in design?

17) What’s necessary to dim a neon sign on stage? What level might it expect to start to flicker out?

18) If you have a 230v rope light and use it on a 120v system, how many amps is a 150' length of it expected to use? In looking up the wattage per foot of rope light in general, what’s the maximum safe length of a single run of it?

19) Given a 2.4Kw modern electronic dimmer at full load at 20%, what’s it’s amperage at the service panel? Is it the amperage of 20% or 100% of the draw? How many amps is 20% of a 2.4Kw dimmer?

20) Based upon a 3/21/05 Martin Technical Brief what fixture can cause the following and what might you do to solve the problem given you can’t put the fixtures on separate circuits: (Hint it’s a note about the compatibility of two of their products.)

xxxxxx Can Cause Voltage Drops

We have seen a number of cases of fixtures resetting intermittently 
when connected to the same AC circuit as xxxxxxx. 

The xxxxxx can draw up to 33 A. The heavy current consumption can 
cause a short voltage drop that is large enough to disrupt the 5V power 
supply in other products like the MAC 2000. If this happens, the 
fixture's main processor drops out and then reboots when the voltage 
comes back up, causing the fixture to reset. 

To avoid this situation, we recommend powering xxxxxx on their 
own separate AC feed. If this is not practical, we we recommend using 
the xxxxx in xxxxx mode, with DIPP-switch xxxxx "xxxx".

21) Explain how the fluorescent starter random flicker effect works and given a 100w lamp and wanting a fast random flash, what type of lamp and specific starter type should you use?

22) How does a “QL” Induction Lighting System work, and what uses might such a system have in lighting design. Can it be dimmed or colored?



23) Given the below chart, and 20' distance on a HPL 575w/C lamp in a S-4 36 degree Leko, what dimmer percentages would be best to accurately reproduce the light of the following light sources?

Lighting Comparison of Fuels:
Tallow candles: 2200 grains consumed per hour; 16 candle power, 1400 Calories heat.
Sperm candles: 1740 gph.; 16 cp., 1137 cal.
Paraffin oil: 992 gph.; 16 cp., 1030 cal.
Kerosene oil: 909 gph; 16 cp., 1030 cal.
Cool gas (argand): 4.8 cubit feet; 16 cp., 1240 cal.
Cool gas (Welsbach): 3.5 cf.; 50 cp., 763 cal.

24) given the above figures, what is the color temperature of the above light sources? In other words, in reproducing or even gelling for a candle on a table, what color temperature is it burning at? We know candlepower is one candle or source of which above or other source type as a bench mark, still what's it's color temperature or that of a flame in general at best? How does one in doing the above calculate a mitered shift anyway due to amber shift? What's the formula as also important to note somewhere in your "Backstage Handbook" hand written notes. 

You do hand write notes into that dictionary do you not? What else is all that extra space for in the book? Read the notes on why such a book came to market and see if you are doing the same or using someone else's notes without adding your own.


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## avkid (Jun 24, 2005)

(5
http://store.dollhousecollectables.com/mh838.html
To install: find a very small electrician!

to be more serious: http://www.visualsystemsandsupport.com/Moonbeamlights/ProductList.aspx

as for install: in the morning!


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## ship (Jun 24, 2005)

On a similar add, just posted off a lighting.com flyer, I sent my boss a add for a MR-16 based out door charcoal grill based magnetic lighting system so you can see your burgers.

To be more specific on the actual question, it's a specific light fixture that's rigged so as to represent say a full or partial moon and will travel in two dimensions across the stage as time goes on during the show. Very important technique and concept for doing theater though it might be called other things at times.

Still, Kudos to your websearch and jokes. You get five points each. Out of a hundred on the other hand...


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## SBHSTECHIELB (Jun 25, 2005)

"17) What’s necessary to dim a neon sign on stage? What level might it expect to start to flicker out?" 

In the past i have worked w/ flouresnt lights on a dimmer.. i dont have a site or anything...what i have done is convertid the plug from edison to stage pin to work on the dimmer... it worked perfictly fine....it started to flicker when i brought it up to about 20% 30%.. give or take.


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## ship (Jun 25, 2005)

in fleshing out your answer, what type of dimmers and lamps much less ballasts were you using?

Can you do a websearch on a lamp company website or in general to further refine your answer as it might or might not relate to dimming neon lamps?

What's the difference between a neon and fluorescent lamp in how they work? Might this be a problem or not much?


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## propmonkey (Jun 25, 2005)

we had a sign in the show were about to close on sunday. when plugged it into a dimmer and we all knew it had to be patched as a non-dim. so during the show we went to fade it and it flickered and went out. the next day i went in and founded out it wasnt patched as it should. at first i couldnt find it. but i figured out if you hit the bump botton then faded it up it would work(neon uses a stepup-transformer so if you dont have enough to start it, it will stop). i finally found the "Full On @ 1%" profile.


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