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Diffusion Filters Gels Research

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#1 Matt Dickinson

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Posted 16 April 2016 - 12:40 PM

Hi everyone,

 

I am a student currently writing about diffusion filters in a short research topic for my BA course. I was wondering if anyone could think of any topics extra I could cover or speak about in more depth. 

 

So far Ive spoken about:

 

basic introduction to difference between soft and hard light

the various diffusion gels available, EG Frosts, Silks, White diffusions and Grid clothes etc.

the results of these gels

the effects of strong vs weak diffusion on the tone of a model

The visible transmission and light absorption of diffusion gels

The effects of increasing and decreasing the gel position in relation to the light and model

The pros and cons of Heat resistant vs non heat resistant gels

how strong diffusion can be used to combine multiple light sources

and some difference in quality between brands

 

What else can I talk about?

 

Thanks

Matt 

 

 


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#2 David Mullen ASC

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Posted 16 April 2016 - 02:06 PM

Sounds pretty thorough.  Just make sure that you define what makes a light soft, i.e. the size of the source (the diffusion frame, not the light behind it) relative to the subject, and how fall-off plays into that, and how evenly the light fills the diffusion frame will affect the quality of the soft light (thus techniques like book-lighting), and how the material spreads the light (such as a silk spreading the light into a cross-shape) and how much specular light might leak through some fabrics thus creating a soft light with faint hard light mixed into it (what some people refer to as the texture of the soft light).

 

Also, make sure you emphasize that there is no hard boundary between hard and soft lighting, lighting can be semi-soft, barely-soft, etc.

 

And different diffusion materials can have a color cast, some intentional.

 

At some point, once a diffusion material has been evenly filled with light from corner to corner with no hot spots (a theoretical state) then it cannot get any softer even if heavier diffusion material is used, the softness at that point is determined by the size of the diffusion frame relative to the subject.  I'm just mentioning this because it is something even professionals don't always grasp, somehow thinking that if they could push the light through something even heavier (like 1" polystyrene!) the light will get even softer, when they are mostly just being inefficient with output at some point once they achieved the maximum spread that the diffusion material and light allows.


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#3 JD Hartman

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Posted 16 April 2016 - 02:28 PM

Are you restricting the topic to traditional lighting gels only or are you including fabrics like tough-spun, muslin, both bleached and natural, etc.?


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#4 Matt Dickinson

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Posted 17 April 2016 - 06:29 AM

Sounds pretty thorough.  Just make sure that you define what makes a light soft, i.e. the size of the source (the diffusion frame, not the light behind it) relative to the subject, and how fall-off plays into that, and how evenly the light fills the diffusion frame will affect the quality of the soft light (thus techniques like book-lighting), and how the material spreads the light (such as a silk spreading the light into a cross-shape) and how much specular light might leak through some fabrics thus creating a soft light with faint hard light mixed into it (what some people refer to as the texture of the soft light).

 

Also, make sure you emphasize that there is no hard boundary between hard and soft lighting, lighting can be semi-soft, barely-soft, etc.

 

And different diffusion materials can have a color cast, some intentional.

 

At some point, once a diffusion material has been evenly filled with light from corner to corner with no hot spots (a theoretical state) then it cannot get any softer even if heavier diffusion material is used, the softness at that point is determined by the size of the diffusion frame relative to the subject.  I'm just mentioning this because it is something even professionals don't always grasp, somehow thinking that if they could push the light through something even heavier (like 1" polystyrene!) the light will get even softer, when they are mostly just being inefficient with output at some point once they achieved the maximum spread that the diffusion material and light allows.

 

Thanks Mr Mullen, you've given me so much more to write about now! Colour casting or light spread were two things I completely forgot about but are so vital.

 

Are you restricting the topic to traditional lighting gels only or are you including fabrics like tough-spun, muslin, both bleached and natural, etc.?

 

 

Mr Hartman, no there is no restriction. As this is an open research assignment, it can cover anything and my goal was to look into anything/everything to do with diffusion gels. Modern or Archaic 


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rebotnix Technologies

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Ritter Battery

Zylight

Abel Cine

Visual Products

The Slider

Paralinx LLC

Rig Wheels Passport

Broadcast Solutions Inc

Willys Widgets

Tai Audio

Aerial Filmworks

Pro 8mm

CineLab