Planning for light throw

[FTOTY]

So, this is my second time designing lights for a main stage production and I need help with one thing: light throw. How do you design/plan for light throw? I might be using the term, and if so, I mean where the light lands-how wide, any shadows, and the like. So far this is the only problem I'm having with my. I was also wondering if there were any lighting design software available online. I've been working from scratch, which isn't bad, but some help would be nice every now and then.

[cutlunch]

Go to the manufacturer's website for the lights you have. And download the light characteristics for each light you are using. This is a chart showing beam size, light level and throw distance. This will give you the info you need.

[Les]

What you are looking for in your instruments is 'photometrics'. This information specifies almost every characteristic of the light's beam. As far as shadows go, you will have them. It's a natural part of lighting design. Embrace it. The challenge is getting them where you want them.

[Inaki2]

There are a bunch of formulas for that. This one's my favorite:
http://www.paul-pelletier.com/LDCalc...ulatorPage.htm

Gotta love it!

[squigish]

This is one of the places where a sectional proves it's value, you need both the plan (horizontal) and sectional (vertical) distances to calculate your throw distance using the pythatorean theorem (a^2+b^2=c^2).

[Inaki2]

If you want the math to do it yourself:

Terminology:
BD: Beam Diameter @ Throw Distance
TD: Throw Distance (how far away the light is to the object)
mf: Multiplying Factor (this is a trigonometric offspring to the field angle)
fc: Footcandles (a measure of light)
pc: Peak Candela (the manufacturer must supply tou with this)

mf: 2 x TAN(field angle/2)
BD: mf x TD
fc: pc/TD^2

[zac850]

In light of trying to avoid school work by doing theater work (what, am I alone in that?), I would agree going to

http://www.paul-pelletier.com/LDCalc...ulatorPage.htm

I use that program (in virtual PC) and it has been a god send. It does any calculation you need, plus some.

[squigish]

Originally Posted by zac850

In light of trying to avoid school work by doing theater work (what, am I alone in that?)

Definately not. That's what I'm doing right now, although one would be hard pressed to call it work...