Design Choosing the Right Diffusion

[poolman78]

Hey all,

I am lighing a Commedia play and the director wants one look, Venice mid-day. I am trying to achieve a single source look, with only one hard shaddow. I want to fill with the same quality of light, but want to use diffusion to not allow any other noticable shadows. Any suggestions which diffusion will give me the best throw while eliminating shadows. I was leaning towards a frost, but so many nice options out there.

Thanks for your thoughts in andvance..

 

[SteveB]

Hey all,

I am lighing a Commedia play and the director wants one look, Venice mid-day. I am trying to achieve a single source look, with only one hard shaddow. I want to fill with the same quality of light, but want to use diffusion to not allow any other noticable shadows. Any suggestions which diffusion will give me the best throw while eliminating shadows. I was leaning towards a frost, but so many nice options out there.

Thanks for your thoughts in andvance..

In truth, only a big 5kw fresnel or something similar gives you a big punchy, daylight, single source w/ one shadow look. Or possibly a very good quality 2kw fresnel in a smaller space, DiSisti, Arri, Mole Richardson units come to mind for efficiency and beam quality. A 2kw lamp in an Altman 8" fresnel doesn't.

Next best might be a couple of 1kw fresnels, or possibly PAR64's, but multiple sources yield multiple shadows and frost won't change that. Usually a fresnel, or even a group of fresnels from approx. the same location would be soft enough to get you close to the effect you are looking for and won't need frost. PARs might need diffusion to soften the harshness of the beam, but I would only use a very light frost- Rosco 132 or so, maybe 119, or GAM or Apollo equiv.

At that point you need to play with fixtures and frosts and all is dependent on where the motivational light is to come from, distance, what gear you have, etc...

SB

 

[JChenault]

As I understand your post - you want to use a frost on the fill light(s) so they do not cast shadows.

If this is the intent, I am afraid you will not have much luck just by using diffusion. Shadows are created when you have an object being lit from a single small location. IE if you have a spotlight which is 20 feet from the actor for you fill, and that is the only light you have on him, you have a small ( four to six inch diameter source) on the actor. From 20 feet that is so small that you will get shadows no matter what you do. Adding diffusion will make the light bigger and dimmer - it will not noticeably reduce shadows.

I would suggest several possible strategies.

• Have multiple fill lights for each area, space them far apart, and run them at a lower intensity. If you don't have enough fixtures to do this, you could try a frost to make a beam bigger so each fixture will hit multiple areas.
• Get close with your lights - and again use multiple lights per area. By getting close you get slightly less defined shadows per unit.
• Look at some kind of system to make the size of the source bigger. IE hang a large white sheet and shine your lights on the sheet. The actor will be lit by the reflected light, not directly by the spot.
• Think carefully about your angles and scenery. Shadows are most noticeable on scenery. If you do your fill from an angle which does not cast shadows on the scenery, any shadows will be less noticable.
• To wash any scenery shadows - consider some lights whose job is to wash the scenery and not the actors.

For your key light - it is not clear to me if you are planning to try and use a single fixture for the key. If so, (and you are looking for a naturalistic look) I would advise against it. The problem is that the rays from the sun are parallel. The rays from a single fixture that you hang in a theatre are not. To get parallel rays you need to use multiple fixtures for the key light - but be sure that you have minimal overlap in any area scheme you use. IE the actor should be lit by as few key lights at any time as possible.

You might have better luck if you think of the challenge as 'Strong parallel rays of light from the sun, and a diffuse wash from the reflected lights on the adjacent buildings' than just shadows.

Good luck - you have set an interesting challenge for yourself.

 

[derekleffew]

From What does diffusion really do? - PLSN :

Diffusion does:
-Spread the field; the heavier the diffusion the more it spreads the field.
-Soften shadows; the longer the throw, the more scattered the light and the softer the shadows become.
-Decrease the intensity of the illumination; the heavier the diffusion the greater the light loss.

On the other hand, diffusion does not convert a point source, like a Leko, to a linear source like a Kinoflo.

It seems to me that no matter how much diffusion you use in a point source, it’s very difficult to obscure textures and age lines. Linear sources and very large sources, like a large diameter Fresnel, do that best. Perhaps that’s why the “jewel” method of lighting, where you surround the subject with many sources, is so popular in Hollywood — it approximates a linear source. If the McCandless method with three points of light is good, then the jewel method with six or so points of light is excellent. Add diffusion and it becomes pure magic.

-From Richard Cadena's December Focus on Design article.