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Grid Cloth, Diffusion, Etc


Brandon Whiteside

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  • 2 weeks later...
Hey everyone,

 

I am trying to get a grasp on all of the diffusions and what they do. Can anyone give me a quick breakdown as far as the numbers and uses go? ie, why grid cloth over full white, what's the best when lighting for night, etc.

 

Thanks!

 

Hi Brandon,

 

We have a breakdown of fabrics and various uses with safety characteristics, stops, etc...on our website here:

 

Fabric Specifications

 

If this doesn't help get you started I know there are other rag and textile companies in the industry that will have descriptions of their fabrics like we do so you can google them and see what you come up with, you just may have to do a little in-depth searching but the information is out there.

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  • 2 weeks later...
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Hey everyone,

 

I am trying to get a grasp on all of the diffusions and what they do. Can anyone give me a quick breakdown as far as the numbers and uses go? ie, why grid cloth over full white, what's the best when lighting for night, etc.

 

Thanks!

 

Valerie's link is a great resource. In your example, I would choose weights of grid (or silks) over 216, 250 and 251 if I were working outdoors. The normal white diff gets really noisy in the wind.

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Cool. Teach me, please.

 

Everyone has their own method. This is what works for me.

 

get a c-stand. put the frame in the c-stand overslung. take your roll of diff, and starting at the top, unroll it downwards. Take two #1s, and put them at the top to hold the diff on the frame, so it can hang freely against it. Unroll to the bottom of the frame, and slice it. Take 2-4 tabs of 2" tape, and tape at the top. Take off the #1s. Then do the same at the bottom, this time pulling it TIGHT. Then do the same with the sides. After its all been taped as tight as it can be with the tabs, take a 4' piece of 2" and run it along the entire side, pulling the diff even tighter. Pull as tight as you can. Dont worry, it won't break (unless it already has a rip/tear in it, then it WILL break). After this is done, label the frame accordingly, along with industry standards ;)

 

Remember, when skinning a frame, the key is to make it as tight as possible. This is not something you will master from a website forum. It is something that needs practice and skill and your own way of doing it. Even experienced grips will vary in their frame-making abilities, and certain diffusions are more difficult to handle than others, simply by the nature of the different materials. Once you get a good one, though, you can put it in a thunderstorm and the only thing you'll hear is your c-stand blowing over.

 

 

-DW

 

PS: if you're ever worried about a stand blowing over, make sure you double-grab.

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  • 2 years later...

Hey everyone,

 

I am trying to get a grasp on all of the diffusions and what they do. Can anyone give me a quick breakdown as far as the numbers and uses go? ie, why grid cloth over full white, what's the best when lighting for night, etc.

 

Thanks!

 

This is a good question that is often misunderstood.

 

First off, I feel sorry for any DP who endures a grip crew that cannot skin a frame of diffusion tightly. It is grip 101.

 

When the sun (a light source) is shinning brightly without any clouds or smog take notice of all the shadows. Get a camera, a cheap one will do, and take some pictures. Get buddy (a subject) and position him so the sun is at his back while you photograph him from the front. Then try it with him facing the sun and then with the sun coming from the side. You can even try 3/4 angles from all sides if you have the time. Just keep track of the suns angle and time of day so you know what you are comparing to. Also find a tree and take a nice wide angle shot that also shows it's sharp, well defined shadow. What you are seeing is "hard light" from the sun with some ambient light reflecting off almost everything. The shadows are sharp because of how far the sun is from us and how small it appears as a source in our sky.

 

The next step of this little experiment is to repeat everything in overcast conditions. Have your subject wear the same clothes, stand in the same place at the same time. Finish with that nice wide shot of the tree. Now take notice of the shadows or the lack thereof. What you are seeing is "soft light." The shadows are softened because the cloud cover is now the source of light which is closer to us than the sun and is larger from our perspective. This principle can be translated with virtually any source and any subject.

 

Grab a small object with texture like a rock or a golf ball. Go into a dark room and turn on a single light. Get as far away from the light as possible and hold your rock or ball to the light. Take notice of the sharp shadows and how little the light "wraps" around. Keep your eye on the ball as you walk it closer to the light. Make sure there is nothing in your path to trip over. Keep going until your are holding the ball or rock next to the light. Sure it is now brighter. Notice the shadows or lack thereof. Take notice of how the light "wraps" around. By moving closer you have decreased the distance of the source and increased the size of the source relative to the ball or rock.

 

The beam coming out of most big studio lights is coming from two sources, the element inside the globe and from the reflector inside the lamps housing. The first order of business is smoothing these two sources out. This applies to groups of lights as well such as Dino's, Kino's, LED's, the goal is to merge everything together to get a single source...causing a single shadow. As the light hits the frame of diffusion it becomes the new source lighting the subject. So the larger and closer your frame is to the subject, the "softer" or more "wrap" the light will have. That is why you will see many DP's bring the diffusion in as close as possible for close ups.

 

So now we have lots of choices in materials to use as a diffuser. Hampshire Frost, Opal Tough Frost, 251,250,216,129,Full Grid, Half Grid, Half Soft Frost...how do we choose? Size is a good start. Most rolls of diffusion cannot be sewn together to make larger frames of diffusion. Our choices for diffusion that are 6'x6' and larger are:

 

Full Grid or Grid Cloth-6

Half Grid or Lite Grid-10

1/4 Grid-5

*All of the grid cloths are now made in a "silent" as well that handles noise caused by wind or rain better.

Full Soft Frost or Full Frost or Shower Curtain-3

1/2 Density Soft Frost or 1/2 Shower Curtain or "Howard"-10

Hilite-1

Bleached Muslin-7

UnBleached Muslin-0

Silk-3

Poly Silk-3

China Silk or 1/2 Poly Silk-0

1/4 Silk-0

Black Silk-1

1/4 Black Silk-0

* Many vendors specializing in overheads also have silks and grid cloths dyed with color correction as well.

 

I may have left some gimmick ones out or forgot some of the nicknames. Now it comes down to preference and how each of these fabrics spread the beam of light and the amount of intensity lost doing so. I have added an arbitrary number after each fabric that rates, 1-10, how often each is used. A zero means I have never used it. Most DP's I work for prefer the Grid Cloths and 1/2 Soft Frost. Using a color correction dyed in is very situational. The choice really comes down to how much intensity can be afforded to lose. Full Grid does a better job of spreading the beam than 1/2 Soft Frost but you lose a lot more intensity.

 

The same basic principles apply for 4'x frames but now you have more options. You should note that as the size of the source changes so does its "fall off."

 

See Inverse Law of Squares:

http://photo.tutsplus.com/articles/lighting-articles/rules-for-perfect-lighting-understanding-the-inverse-square-law/

 

Opal, 250, 216 are the most used outside of the grids and 1/2 SF for me. How well a diffuser does in high heat is a consideration. Clipping 1/2 SF to the barn doors of a hot light may not be the best idea. Opacity may be what decides which material to apply to windows as a frosted look.

 

Order a few cuts of some of these and play. Take notice of the shadows and how much intensity is lost.

 

Please spare me any comments of how you or your DP likes to make 20'x20' frames of 216.

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In my eternal quest to simplify matters, we could just think of diffusion as "light," "medium," and "heavy;" that is Opal, 250, 216. For frames of 4'x4' and smaller, these gels seem to work best; grid cloth that is taped beautifully to a frame one day is droopy and noisy the next. For bigger frames light, medium and heavy is 1/4 grid, 1/2 grid, and full grid. For extra light diff, you've got hampshire frost, 1/2 opal, and 1/2 soft frost. Extra heavy would be 129, or bleached muslin. A good DP will know better than to ask the grips to carry three 4'x4''s of everything, gels and grids (and an assortment of color); you're just slowing yourself down.

 

If you're on a tight budget, 250 or Light grid are the ones to buy.

 

Does anyone ever use silk anymore?

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A good DP will know better than to ask the grips to carry three 4'x4''s of everything, gels and grids (and an assortment of color); you're just slowing yourself down.

 

 

 

You need to have a word with Bob Richardson .... Amongst other things I have on my trucks - three 80 x 200 silent black grids.

Edited by Sanjay Sami
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You need to have a word with Bob Richardson .... Amongst other things I have on my trucks - three 80 x 200 silent black grids.

 

Mr. Richardson is one of a small group of DPs that can almost do whatever he wants nearly without question and he loudly exercises that power. I have even heard many of his ASC peers refer to him as "a true genius" but also as "The White Devil." Chris Centrella, his Key Grip, also helps him out tremendously by being very frugal with both gear and manpower. For example, Mr. Richardson likes to spend the day (almost everyday) calling the shots off of a rideable crane arm. Rather than get a Chapman Super-Nova, which is quite arguably the best (and most expensive) rideable crane in the business, Chris chooses a lesser known crane that doesn't come with a tech and is about 1/4 of the cost. Respectfully, by nature Mr. Richardson is quite impatient, this leads Chris to come up with rigs that are quicker and more versatile (down and dirtyesque) rather than big, slow truss monstrosities that come with large rental and manpower costs.

 

Mr. Richardson is an exception and there are a few others out there. These exceptions are becoming fewer and fewer. I am not going to publicly mention names of once A List feature DP's that are having a hard time finding work because of the costs associated with them. But there are several of them. The days of being a "cowboy" are coming to an end. Feature films are becoming more and more cost driven. Wiping out 35MM film for digital is a bit of a danger. The looks producers give when a DP wants an ArriMax on a digital shoot is quite disgusting.

 

Samjay, why do you keep three 80'x200' black silks on your truck for a DP that rarely films in India? That seems like a lot of wasted space that could be filled with something that is used more often...

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Samjay, why do you keep three 80'x200' black silks on your truck for a DP that rarely films in India? That seems like a lot of wasted space that could be filled with something that is used more often...

 

Only bring it in when I am working with Bob.

 

Chris is a good friend of mine.

 

The GF 16 crane is co-owned by Bob and Chris. While that crane is not well known in the States, it is a very popular ride on and remote crane elsewhere. Bob can be maddening with his "Bob-Com" radio commands whilst a shot is in progress, but in general, once you get used to it, it adds a lot of speed and reduces stress on set. I work with him in south east asia as well.

 

Chris did Hugo with him in the UK, but Dieter Bahr was his Key Grip on Inglorious Bastards in Germany. Dieter did not get on well with him, from what I have heard :-)

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Only bring it in when I am working with Bob.

 

Chris is a good friend of mine.

 

The GF 16 crane is co-owned by Bob and Chris. While that crane is not well known in the States, it is a very popular ride on and remote crane elsewhere. Bob can be maddening with his "Bob-Com" radio commands whilst a shot is in progress, but in general, once you get used to it, it adds a lot of speed and reduces stress on set. I work with him in south east asia as well.

 

Chris did Hugo with him in the UK, but Dieter Bahr was his Key Grip on Inglorious Bastards in Germany. Dieter did not get on well with him, from what I have heard :-)

 

That is so funny. I now Key for the only other DP in Hollywood that I know of that uses the intercoms. In fact, I am wearing one now as I write this. Ask Chris if he knows of another DP who uses them. He'll chuckle but know exactly who I am with. Chris was his Key at one time as well. I have met Chris only once but alot of his crew are guys who came up under me and give me lots of good stories. Small world.

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The devil is in the details... thanks for sharing this.

I like these types of thorough tests and would love to do them myself.

 

It's interesting to see the minute and subtle changes and how much they matter in respects to pass a certain look. I can see why DPs would choose the full and half grid before anything else, it looks very pleasing and the tonality is nice.

I know "common" people probably wouldn't know the difference as to explain it with words, but I do believe that we perceive a whole lot more than we think we do and therefore to me it makes a huge difference wether or not one picks one over the other for specific purposes.

 

Thanks again.

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  • 3 years later...

Hi Brandon,

 

We have a breakdown of fabrics and various uses with safety characteristics, stops, etc...on our website here:

 

Fabric Specifications

 

If this doesn't help get you started I know there are other rag and textile companies in the industry that will have descriptions of their fabrics like we do so you can google them and see what you come up with, you just may have to do a little in-depth searching but the information is out there.

I'm sorry, can anyone find a similar page in the present Matthews site, since this link is blind?

 

thanks

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