Bounce vs. Shoot Through Diffusion

R

Ronald Gerald Smith

Active member
What are the advantages of Bouncing vs. Shooting through diffusion, and vice versa?

I know that both are very commonly done, but I want to know what are the advantages of each?

I don't have the money to rent a bunch of lights at the moment and do technical tests, so I want to hear from your experiences.

I am guessing that shooting through diffusion has more throw, and bouncing has faster falloff. Shooting through diffusion may be easier to flag off (or harder). Again, these are just guesses. Let's say that we are using a 1k light. We have one 48x48 inch bounce board and one 48x48 inch sheet of diffusion. What differences would I be seeing?

Thanks!
Ron
 
Bounce lighting lighting can be done with less expensive materials, and, MAY, need less set space to pull off. The quality of the light generated by a soft source is based on the size of the source. To get the size that you want shooting through diffusion may mean having to have the space behind the diffusion set up to put the lights, and get the source size right. Setting the source size with a bounce light may mean moving the light away from the bounce material from the front, which may be easier in smaller spaces. Also, care must be taken to get the proper diffusion material to shoot through, while a bounce source can be as simple as a piece of foam core, show card, a white sheet, or even just a white wall or ceiling. Both can be difficult to control, but, I have found that setting up a bounce source is quicker.
 
David G. Smith said:
Bounce lighting lighting can be done with less expensive materials, and, MAY, need less set space to pull off. The quality of the light generated by a soft source is based on the size of the source. To get the size that you want shooting through diffusion may mean having to have the space behind the diffusion set up to put the lights, and get the source size right. Setting the source size with a bounce light may mean moving the light away from the bounce material from the front, which may be easier in smaller spaces. Also, care must be taken to get the proper diffusion material to shoot through, while a bounce source can be as simple as a piece of foam core, show card, a white sheet, or even just a white wall or ceiling. Both can be difficult to control, but, I have found that setting up a bounce source is quicker.
Click to expand...

Hey thanks for this great explanation. Do you know the difference in throw or falloff between bouncing and shooting through diffusion? I know that both are difficult to control, but which do you think is easier, or require less complex flagging?
 
Ronald Gerald Smith said:
Hey thanks for this great explanation. Do you know the difference in throw or falloff between bouncing and shooting through diffusion? I know that both are difficult to control, but which do you think is easier, or require less complex flagging?
Click to expand...

They both have problems with controlling spill, but I give shooting through diffusion has an edge in that lighting control, like louvres, or edge control devices can be set up on the diffusion set up it self. With bounce you sometimes get into have more free standing flags, nets and other light control devices in front of the bounce source.

What I have like to do with bounce lighting is to use existing architectural elements for light control. For example, setting up a bounce source out side of doors, or windows, pointing into the room. However, when brought into the set then plan on breaking out flags and/or nets to get it to where you want.

Bounce sources do eat up less of the quantity of light, in most instances, I have found.

As far as soft sources go, good soft boxes are a very good way to go, along with having a few china balls, and some set ups for bounce lighting (foam core, some C-stands, flags, ect).
 
Ronald Gerald Smith said:
Does this mean that a light source, for example a 1k, loses less stops when bounced rather than being shot through material, which would lose about 1 or 2 stops?
Click to expand...

The light falloff follows the laws of physics. No matter the source. With a bounce, the distance is measured from the source to the bounce, plus the distance from the bounce to the subject. However, since there is nothing cutting the light from the source to the bounce, you get the full effect of that light.

When shooting through diffusion, you have to back the light back enough to fill the diffusion frame. You are often setting the light to flood mode which disperses it's output somewhat. Once it gets the the diffusion, the diffusion may lose 1/2 a stop to more than 3 stops depending on what you're using. That lowered light level then has to reach the subject.

As a general rule, if I am lighting a single subject in a close shot, it's usually easier to place the diffusion right outside of frame, and hit that diffusion with whatever instrument necessary. If I've got a large group to light, or a larger area to light, I am going to be bouncing. Controlling bounced light is a chore and frankly I wouldn't bother. I approach bounced light much like I would a window. It becomes the large key I don't want to control much of.

Once you use each of these types of light a few times, you'll get a good idea for what it is you need.
 
PerroneFord said:
The light falloff follows the laws of physics. No matter the source. With a bounce, the distance is measured from the source to the bounce, plus the distance from the bounce to the subject. However, since there is nothing cutting the light from the source to the bounce, you get the full effect of that light.

When shooting through diffusion, you have to back the light back enough to fill the diffusion frame. You are often setting the light to flood mode which disperses it's output somewhat. Once it gets the the diffusion, the diffusion may lose 1/2 a stop to more than 3 stops depending on what you're using. That lowered light level then has to reach the subject.
Click to expand...

This is a very thorough explanation. Thank you. That makes complete sense, and definitely gives me a clear idea of what I need to do.
 
David G. Smith said:
They both have problems with controlling spill, but I give shooting through diffusion has an edge in that lighting control, like louvres, or edge control devices can be set up on the diffusion set up it self. With bounce you sometimes get into have more free standing flags, nets and other light control devices in front of the bounce source.
Click to expand...

I understand that the the type of diffusion you are talking about (which makes it possible not to be using too many free standing flags and free standing light controllers) is a soft box, right? Thanks for that, just clearing it up in my head, although common sense tells me that you were talking about a soft box type setup, not a diffusion frame setup.
 
David G. Smith said:
What I have like to do with bounce lighting is to use existing architectural elements for light control. For example, setting up a bounce source out side of doors, or windows, pointing into the room. However, when brought into the set then plan on breaking out flags and/or nets to get it to where you want.
Click to expand...

That makes complete sense. I often see people bouncing large HMIs into big bounces outside of windows. But I guess this applies to all situations; it's a good practice to use 'existing architectural elements for light control', whether it is a bounced light, shoot-through-diffusion light, or direct hard light.
 
Ronald Gerald Smith said:
That makes complete sense. I often see people bouncing large HMIs into big bounces outside of windows. But I guess this applies to all situations; it's a good practice to use 'existing architectural elements for light control', whether it is a bounced light, shoot-through-diffusion light, or direct hard light.
Click to expand...

The first question you should be asking yourself when you determine that you need more light on a set is "where should that light be coming from". At least if you want that light to look natural.

In a home, there are generally only 3 possible sources of light.

1. The windows
2. Overhead lights
3. Table, floor, or desk lamps.

So if you are lighting a home (or most other indoor structures), if you want the light to look natural or motivated, you need to try to replicate these sources. So study photographs of homes. Study how sunlight comes through windows. Study how desk and floor lamps project onto the floor, walls, and ceiling. Study how things look when a person moves from a sunlit window to a chair or sofa in the living room, and then turns on a TV. Watch the shadows on the face. Watch the color temperature change.

It is only by watching these things that you will learn an understanding for how to replicate them with instruments. And remember, the most natural light of all, is the light that already exists. So ask yourself if you can actually light your scene adequately with the light already present.

I recently did a shoot in a home. the house had wood floors that were very reflective. It had white walls and ceiling, and it had lovely sunlight coming in. To light that home, I simply replaced the existing bulbs with stronger compact fluorescent bulbs. The scenes looked very nice and "unlit". I did have to augment a kitchen scene with a softbox, but that was the only light I needed to use. Easiest lighting job I've ever done. One instrument, and one C-Stand. With no flags. Color temperature was a pain because the overhead lights weren't color matched, and weren't blending well in some rooms. But that's something I'll fix in the color grade.
 
PerroneFord said:
And remember, the most natural light of all, is the light that already exists. So ask yourself if you can actually light your scene adequately with the light already present.
Click to expand...


Perrone, your comment made me think a little bit. Before I have been focused on modeling subjects and giving them just the right exposure, just the right kicker or the perfect backlight. This might have been a popular way of lighting a scene a long time ago, but with modern filmmaking, especially with the advantage of faster film stocks and faster lenses, it seems to be the total opposite. Everything is looking more 'unlit' and natural. Sometimes the subject is lit with just a gentle wash of light, a stop or two underexposed---but the rest of the frame is lit in a way that it holds a certain depth and tonality, which makes the frame interesting. I've been too focused on the subject in the past. I need to focus on the whole frame, and the naturalness of it.
 
David G. Smith said:
Bounce sources do eat up less of the quantity of light, in most instances, I have found.
Click to expand...

Just a guess... bounced light is dependent on the reflectivity of the material... so if you have a 95% 'reflective' material, you have 95% of the light hitting the 'target' of the bounce.

Where as a diffusion is based on transmissivity of the material... so if you have 50% transmission of the light... well, that's half the light... a diffuser that passes 95% of the light would perhaps not be worth it... or give just a hint of 'light pattern' perhaps.
 
You did not mention what grade of diffusion you are using. This has a huge bearing on the transmission of light.
 
PerroneFord said:
I recently did a shoot in a home. the house had wood floors that were very reflective. It had white walls and ceiling, and it had lovely sunlight coming in. To light that home, I simply replaced the existing bulbs with stronger compact fluorescent bulbs. The scenes looked very nice and "unlit". I did have to augment a kitchen scene with a softbox, but that was the only light I needed to use. Easiest lighting job I've ever done. One instrument, and one C-Stand. With no flags. Color temperature was a pain because the overhead lights weren't color matched, and weren't blending well in some rooms. But that's something I'll fix in the color grade.
Click to expand...

I've not done 'movies' in houses, but when I had aspirations as a still photographer, I would spend some amount of time 'augmenting' a natural lit house with some form of lights to soften 'deep shadows', or catch light for dark 'wood' furniture. The same principle as a catch light on eyes...

But in any case I was shooting film, and could adjust shutter and f-stop to give deep focus, and processing to compensate some what for highlights.
 
j1clark@ucsd.edu said:
I've not done 'movies' in houses, but when I had aspirations as a still photographer, I would spend some amount of time 'augmenting' a natural lit house with some form of lights to soften 'deep shadows', or catch light for dark 'wood' furniture. The same principle as a catch light on eyes...
Click to expand...

Exactly. Nothing is different. But when assessing the "directionality" of that light in the movie world, one has to be cognizant that another shot may well show the room from other angles. With a single still, you can cheat as much as you like because the audience will never see the other light sources. But if you shoot a master in a room, and it shows two large windows, an overhead fluorescent, and a desk lamp, then you really need to try to preserve direcitonality such that it "appears" that the actors are being lit by one of those sources.

This is not always true, but if you are going for the unlit look, it becomes somewhat important. Color is important too. I have yet to walk into a home where every single lamp in the home matched color exactly. So I generally take some pains to craft the light so that not everything looks exactly the same. Balancing to daylight allows things like the incandescent lights to read normally, allows TV light to show slightly blue, etc.

j1clark@ucsd.edu said:
But in any case I was shooting film, and could adjust shutter and f-stop to give deep focus, and processing to compensate some what for highlights.
Click to expand...

No different in digital filmmaking depending on the tool.
 
PerroneFord said:
The first question you should be asking yourself when you determine that you need more light on a set is "where should that light be coming from". At least if you want that light to look natural.

In a home, there are generally only 3 possible sources of light.

1. The windows
2. Overhead lights
3. Table, floor, or desk lamps.

So if you are lighting a home (or most other indoor structures), if you want the light to look natural or motivated, you need to try to replicate these sources. So study photographs of homes. Study how sunlight comes through windows. Study how desk and floor lamps project onto the floor, walls, and ceiling. Study how things look when a person moves from a sunlit window to a chair or sofa in the living room, and then turns on a TV. Watch the shadows on the face. Watch the color temperature change.

It is only by watching these things that you will learn an understanding for how to replicate them with instruments. And remember, the most natural light of all, is the light that already exists. So ask yourself if you can actually light your scene adequately with the light already present.

I recently did a shoot in a home. the house had wood floors that were very reflective. It had white walls and ceiling, and it had lovely sunlight coming in. To light that home, I simply replaced the existing bulbs with stronger compact fluorescent bulbs. The scenes looked very nice and "unlit". I did have to augment a kitchen scene with a softbox, but that was the only light I needed to use. Easiest lighting job I've ever done. One instrument, and one C-Stand. With no flags. Color temperature was a pain because the overhead lights weren't color matched, and weren't blending well in some rooms. But that's something I'll fix in the color grade.
Click to expand...

Outstanding. Most of the fictional narrative I have done has been low budget sci-fi or horror that required a more stylistic approach. I am excited about a project I will be doing this fall that is a drama, and I am hoping to exploit an approach very much like that.
 
Ronald Gerald Smith said:
Perrone, your comment made me think a little bit. Before I have been focused on modeling subjects and giving them just the right exposure, just the right kicker or the perfect backlight. This might have been a popular way of lighting a scene a long time ago, but with modern filmmaking, especially with the advantage of faster film stocks and faster lenses, it seems to be the total opposite. Everything is looking more 'unlit' and natural. Sometimes the subject is lit with just a gentle wash of light, a stop or two underexposed---but the rest of the frame is lit in a way that it holds a certain depth and tonality, which makes the frame interesting. I've been too focused on the subject in the past. I need to focus on the whole frame, and the naturalness of it.
Click to expand...


Whoa now, good cinematography isn't lighting for exposure but lighting to tell a story. No matter how fast your film/sensor is, that won't make the image tell a story any more than simply throwing enough light onto the scene to make an image appear.
 
Just a random note from a great cinematographer on the general topic of bounce vs. diffusion.

Mr. Deakins wrote back in April of 2010:

"The closer the bounce source is to the subject then, generally, the softer the light is. I usually will place a bounce card close to the side of frame but I have used a large bounce source as an overhead. For the scene you ask about I was using an 8' x 4' piece of unbleached muslin close to the edge of frame. Sometimes, if I am faced with a wide shot I might change to projected light through a large diffusion in order to cover the larger area. In the case in point I might well have had to compromise the wide shot as, given the restrictions of the location, it would have been very difficult to match the look I was giving the close shots. There is no exact way of using any light source and the choice of one over another is often conditioned by the space."

http://www.deakinsonline.com/forum2/viewtopic.php?f=1&t=1362
 
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