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Old January 12th, 2014, 10:20 AM   #16
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Re: Shooting subject on a black background

Jody,
Make sure that you use "manual" iris and stop the lens down. If you shoot it in "auto" the camera will see that black background and think it needs to open up the iris too much, and overexpose your subject. Guaranteed. Good luck.

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Old January 12th, 2014, 02:27 PM   #17
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Re: Shooting subject on a black background

There's already some really good advice on this thread, but I'll add:

Make sure you black balance the camera just prior to shooting so the blacks don't have any color tint.

And also make sure the master black levels are set correctly in the camera's menus or you'll end up with a dark gray background that will have to be dropped down in post. Many cameras are incapable of producing a true, 0 IRE, black with the factory default settings. Don't believe it? Put a lens can on a new Sony camera and check the levels on a scope. Black won't hit zero. I suspect other brands of cameras might be the same, but I have more experience with Sony. Just another example of why custom Picture Profiles are pretty much required for modern cameras.

I would also ask if black is actually a creative decision or if it was chosen because the location does not have a suitable "look". Black isn't very interesting for the viewer and I feel that it has a claustrophobic feel to it. Black is my absolute last choice for background options. Maybe consider shooting on green screen and dropping in a more lively background that is appropriate for the subject matter: http://www.instabackgrounds.com/
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Last edited by Doug Jensen; January 12th, 2014 at 03:35 PM.
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Old January 12th, 2014, 04:26 PM   #18
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Re: Shooting subject on a black background

Quote:
Originally Posted by Charles Papert View Post
Stephen, Jim had it correct--the closer a source is, the larger it is in relation to the subject and thus softer. Think of it this way: if you were to look at a 1x1 panel that is 6 feet away and another at 12 feet away, the one at 12 feet will appear smaller in size. Smaller sources are harder sources.
Gentlemen,

First let me say I try hard not to post anything as advice unless I think I know exactly what I am talking about. I would never want to be a forum idiot that spreads rubbish. So I apologize to everyone if I made an erroneous statement.

Second, please help me wrap my head around this because light and distance is a concept I have practiced for many years. When it comes to “larger is softer concept” I have never thought of it in terms of applying fixture size in its literal dimensions to the concept. I was taught to think about ALL lighting in terms of the light coming from the fixture. What type of source it is and what happens to it after it leaves the source. I do not understand your concept of closer is larger, therefore softer. For simplicity, if you placed a bare bulb pro light at a 45 degree angle to a subjects face at two feet you would have harsh shadows. If you move that light back 10 feet on the same plane the shadows will soften. They will soften because the light rays have broadened and are no longer focused so intensely on the subjects face. Therefore, it could even be said that it is a larger source based on the spread of the beams. So what am I missing? I do not understand the concept of “closer is softer based on distance because the source is bigger”?

Steve

I am not very clear above. I do understand large vs small source is large is softer, small is not. The part I am not understanding is, how moving a source closer makes it softer? That has not been my experience.
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Last edited by Steven Digges; January 12th, 2014 at 05:23 PM. Reason: clarity
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Old January 12th, 2014, 05:32 PM   #19
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Re: Shooting subject on a black background

That's not what happens - the further away a source is, the light reaching the subject from it is nearer parallel. The proof of course is to consider the sun - 93 million miles away, and when it hits an object ib#n the path to the subject the shadow is hard. A lightsource close, even a old fashioned tungsten lamp has a defined filament length where the light is produced, and this produces a quantifiable angle of light output, which means that the object creating the shadow will mask some of the light from the filament but not all, giving softer edges.

In fact the types of spotlight that can project a gobo are all better when they use a lamp with smaller filament. In the UK, historically our lamps have always had bigger filaments because of our higher voltage supplies, so our projections were not so sharp. There is also a very old design to project shapes - a Linnebach projector, and for these to be sharp, the filament had to be as small as possible.

So any source of light with an object interrupting the light on the way to the subject give sharper shadows as the distance gets bigger. That's how it works. Obviously an LED panel is a bigger source so softer still, but move one further away and the shadows sharpen again. Just down to angles and trigonometry really.

This could help http://en.wikipedia.org/wiki/Umbra
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Old January 12th, 2014, 05:51 PM   #20
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Re: Shooting subject on a black background

Hi Steve,

I'll try to explain. Your light bulb example deals with what is for all intents and purposes a point source or you can treat it as one since you have a small filament emitting light, and it's emitting light in pretty much all directions. If the light is 4 feet from the subject the intensity of the light per square inch is the total light intensity divided by the surface area of a sphere with a radius of 4 feet. If the light is moved to 5.6 feet the light intensity per square inch is the bulb intensity divided over a sphere of radius 5.6 feet and if you do the math the result should be half the 4 foot value. This is the essence of the inverse square law, distribution of the energy over a spherical surface. This has nothing to do with the quality of the light but it will be important when I get to broad sources. Assuming your bulb is in free space and the light is not reflecting off of walls etc., the light that is spread over a larger area as you state, but less of it is hitting your subject and only what are essentially parallel rays are hitting your subject in either case, thus the light is contrasty and of the same quality.

Now switch to a broader source like a 1x1 LED panel. Each LED can be thought of as a point source and the panel can then be thought of as an array of point sources. When the panel is close to the subject the distance of each LED to the subject varies per the pythagorean theorem - the LEDs at the edges provide less intensity than those in the center. Due to perspective and shape of the subject, some LEDs may illuminate an area not seen by other LEDs, while other areas might be illuminated by all the LEDs (cheek vs. front of face for example). Furthermore each LED that is off-axis from the center is illuminating the subject at more of an angle. One might not think of a 1x1 as a broad source, but the same logic applies to a 3x4 foot soft box.

Now start moving the LED panel away from the subject and a couple of things happen. First the ratio between the distance of the center and off-center LEDs from the subject approaches 1 (equivalence), and the light striking the subject from the LED panel becomes more parallel and thus harder or more contrasty. As the distance of the panel increases greatly it becomes effectively a point source.

The Sun is a good example. It's big but it's so far away you can think of it as a point source and it's light is considered contrasty/harsh, unless it's hitting a big soft box (cloud) or one of the California Sunbounce panels.
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Old January 12th, 2014, 06:31 PM   #21
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Re: Shooting subject on a black background

Paul & Jim,

Thank you, now I get it! That makes sense. And another light went on for me. I think what I was perceiving as softer light when you move a source farther away was a lessening of INTENSITY in the shadows. As you have explained so well, it is not softer. But the shadows are not as deep and dark (to me) so I was perceiving it as softer. And, unless you are shooting on a black set, lights farther back provide more opportunity for reflected fill light, also reducing shadow intensity. Does that make sense?

I guess I am lighting more from experience and instinct over technical science.


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Old January 12th, 2014, 07:15 PM   #22
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Re: Shooting subject on a black background

Quote:
Originally Posted by Steven Digges View Post
...I do not understand your concept of closer is larger, therefore softer. For simplicity, if you placed a bare bulb pro light at a 45 degree angle to a subjects face at two feet you would have harsh shadows. If you move that light back 10 feet on the same plane the shadows will soften. They will soften because the light rays have broadened and are no longer focused so intensely on the subjects face. Therefore, it could even be said that it is a larger source based on the spread of the beams...
If you have a small source, like a filament in an unfrosted tungsten bulb, it will always cast harsh shadows... but, as you move it further away from the subject, you'll increase your exposure to compensate.

As you increase exposure, you'll be keeping your facial highlights at perhaps 80 IRE, but you'll also be bringing up exposure in the shadow areas.

What is illuminating those shadow areas? Ambient light, or perhaps your bulb's reflections off walls, ceiling, tables, desks, floors, etc.

However, if you did this same exercise on a dark night, shadows on your subject's face would remain heavily shadowed. No ambient light, no reflective surfaces.

In this sense a hard source always remains a hard source... but what happens to the light after it leaves the source will vary with the environment.

Now, to a soft source: If you are the subject, and a 24" wide softbox is touching your nose, that's a very large, soft source. Measure it in degrees of width - let's say 140-deg. If you could get a camera in there you'd find no shadows.

Now let's move that softbox to a more typical position, 5' from your nose, 45-deg to the side, 45-deg above your eyeline. It's narrower, right? (measure in degrees) I don't have the math to tell you exactly how much, but what is important is the angular size of the source. In the dark of night with no other reflective surfaces in play, the further away the soft source is, the more it "hardens" because its angular size gets smaller.

Of course we don't do much shooting in perfectly non-reflective environments, but, the closer a soft source is, the more wrap there will be, the softer the falloff between highlight and shadow, and the more detail there will be in a shadow area.

OTOH, an instrument like a typical fresnel, leko, or open face is always a "small" and narrow source, and will tend to produce harsh shadows at any usual working distance... which may be softened by ambience or reflections, depending.
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Old January 12th, 2014, 07:40 PM   #23
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Re: Shooting subject on a black background

Thanks all! I spent a couple of hours setting it up last night, and ended up getting the exact look I wanted.

On another note, I just realised how bright my LED panels actually are, I needed them dimmed to 5% to get the correct exposure and not blind the subject.

All of your tips and info is really appreciated, thanks again :)
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Old January 12th, 2014, 09:17 PM   #24
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Re: Shooting subject on a black background

Hi Jody

Could you show us a still from the footage?
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Old January 12th, 2014, 09:57 PM   #25
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Re: Shooting subject on a black background

Quote:
Originally Posted by Tim Lewis View Post
Hi Jody

Could you show us a still from the footage?
Sure. You'll have to excuse my ugly mug, my (much prettier) test subject has left for the day.

Any tips on how to perfect that shot? Keeping in mind framing & exposure might be a bit off since I'm in front of the camera, I just flicked over to full auto :)
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Old January 12th, 2014, 10:21 PM   #26
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Re: Shooting subject on a black background

Unless there's some creative idea driving it otherwise, I like the shoulders turned more and not so parallel to the sensor.
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Old January 12th, 2014, 10:30 PM   #27
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Re: Shooting subject on a black background

Thanks Jody, That looks good. You have chosen a fairly flat lighting style by the looks of it, but the subject is well delineated from a background that is solidly black.

I have also just seen Les's post and would agree with that too.
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Old January 12th, 2014, 10:37 PM   #28
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Re: Shooting subject on a black background

Thanks for that. You say the lighting style is quite flat. What techniques can be used to make it a bit more interesting?
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Old January 13th, 2014, 12:26 AM   #29
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Re: Shooting subject on a black background

If you change the power in one of the panels and meter for the higher output, you will effectively make the areas lit solely by the other panel dimmer or more in shadow.

I would suggest raising the power of one rather than lowering it as this is more likely to keep the background black.

This would be be the "key" light. The other light at the lower power is the "fill" light.

If you are having trouble with the power of the lights and exposure for the camera, just move the fill light further away from the subject and keep the same exposure.
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Old January 13th, 2014, 03:14 AM   #30
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Re: Shooting subject on a black background

Any value and looking at this "issue" sideways"? How about Blue/Green screening and subbing out to a controlled black levelled Graphic?

Doable?

Grazie
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