How to avoid shadows on backdrop?

Angmo wrote in post #18221263
I'd be under a table too.

I'll bet he didn't tell his wife about being under table for that. I know I'd have told her about the HUGE studio, 150' x 300' studio, it was shot in, using my 800mm lens..

Two methods to avoid shadows on the backdrop:
Blow out the backdrop to white.
Use a backdrop where shadows aren't objectionable, and position the lights so the shadows fall behind the subject.

My task was to make updated promo photos of my stage troupe, and I wanted to get two different looks for each performer. We found out the morning of the shoot that the dance studio we were going to use was double-booked, so we got bumped. We wound up going to one of the performer's houses to do photos, so my space was extremely constrained.


Example 1, blown-out white backdrop. I was using the last little scrap of my small roll of seamless paper - I wanted to use the big roll but just didn't have room. To properly light the backdrop, I need some distance between the subject and the backdrop. But to make sure the subject stays within the edges of the backdrop, I have to use perspective appropriately, and stand far away from the subject. I literally shot from the other room through the doorway to get this perspective.

BTS shot: I have two Speedlights to light the backdrop, one sitting on the mantel to the left, and one on a little stand to the right. The main light is a reflective brolly box umbrella with a third Speedlight. The low ceiling gives lots of bounce from the relatively large main light, so shadows on the subject are soft and not deep. The subject stands at the edge of the rug (where that feather is), and I back up through the doorway behind me and shoot with the 70-200 lens.

I also like to use this shot as an example of when to throw the histogram out the window.

BTS:

IMAGE LINK: https://flic.kr/p/oUCt​TD

IMAGE LINK: https://flic.kr/p/pRNg​wx

IMAGE LINK: https://flic.kr/p/pzCX​tG

IMAGE LINK: https://flic.kr/p/pPWo​e1

dmward wrote in post #18221243
Have a look at THIS. This session was shot in her living room, about 10 feet from dining room table to sliding glass door. I was under the table for most of the shoot.
Large PLM camera left, mid-sized PLM for fill over camera position, or just right. Two mid-sized PLMs for kickers and background. All had Einstein 640s in them. White muslin hanging from a background stand setup against the sliding glass door.

I think those are very nice. Thanks!

Wilt wrote in post #18221559
First of all, Fill NEVER 'fills shadows', it merely reduces the contrast difference of the shadow...once the shadow is cast it never goes away!

Of the three points you listed, the first two are to make it so your shadows cast on the background merely have fallen out of the line of sight of the lens (down, and/or to the side) , or are hidden by the body of the subject...and this is true regardless of the light comes from the Main or from the Fill source.

More distance to the background, COMBINED with less distance to the subject, takes advantage of the Inverse Square law to reduce the relative intensity of the light on the background vs. the subject. For example...

• Subject-to-light distance 2.8', background-to-light distance 5.6' (background 2.8' behind subject), light on backdrop is -2EV relative to subject
  
• Subject-to-light distance 4', background-to-light distance 6.8' (background 2.8' behind subject), light on backdrop is -1.5EV relative to subject
  
• Subject-to-light distance 5.6', background-to-light distance 8.4' (background 2.8' behind subject), light on backdrop is -1.1EV relative to subject
  
  
• Subject-to-light distance 2.8', background-to-light distance 6.8' (background 4' behind subject), light on backdrop is -2.6EV relative to subject
  
• Subject-to-light distance 4', background-to-light distance 8' (background 4' behind subject), light on backdrop is -2EV relative to subject
  
• Subject-to-light distance 5.6', background-to-light distance 9.6' (background 4' behind subject), light on backdrop is -1.5EV relative to subject
  
  
• Subject-to-light distance 2.8', background-to-light distance 8.4' (background 5.6' behind subject), light on backdrop is -3.1EV relative to subject
  
• Subject-to-light distance 4', background-to-light distance 9.6' (background 5.6' behind subject), light on backdrop is -2.6EV relative to subject
  
• Subject-to-light distance 5.6', background-to-light distance 11' (background 5.6' behind subject), light on backdrop is -2EV relative to subject
  

...so you see the benefit of both positioning the light closer to the subject AND the subject farther from the background, in terms of the relative amount of light falling on the background.
Distance to the background increase also helps for flagging off light from getting to the background, and it allows more space for YOU to delivberately PUT light behind the subject to fall specifically on portions of the background, if YOU wish.

That makes sense in several ways. Thank you!

m.good wrote in post #18222847
Here is basic lighting setup I start with, I never get a shadow on the background.
Listed is the main camera and lens I use.

Gallery photo (hosted):
posted by m.good originally in forum: Flash and Studio Lighting

Thank you! Your main light is two 150W lights, not a flash/strobe? The main fill behind the camera is the native room light?

I must confess that I don't understand expressing lighting in f-stops. I've seen it referenced this way before. Can anyone point me where to get a grasp on that?

KatManDEW wrote in post #18227881
Thank you! Your main light is two 150W lights, not a flash/strobe? The main fill behind the camera is the native room light?

I must confess that I don't understand expressing lighting in f-stops. I've seen it referenced this way before. Can anyone point me where to get a grasp on that?

Do you have a light meter?

KatManDEW wrote in post #18227881
I must confess that I don't understand expressing lighting in f-stops. I've seen it referenced this way before. Can anyone point me where to get a grasp on that?

Exceedingly simple concept...

Example 1:

Meter one light, get something like 1/60 f/4; meter other light, get something like 1/60 f/2.8
f/2.8 vs. f/4 is -1EV (second light is weaker than first light by -1EV)

Example 2:

Meter one light, get something like 1/60 f/5.6; meter other light, get something like 1/60 f/2
f/2 vs. f/5.6 is -1EV (second light is weaker than first light by -3EV)

In Post 19 I deliberately chose Distances which were numbers like folks are accustomed to seeing for f/stops...most folks do not understand a concept that if I move a light from Distance A to Distance B, the intensity of the light behaves much like f/stop distances...moving light from 4' to 8' means the light on the subject is -2EV weaker at the farther distance!

KatManDEW wrote in post #18227881
...I must confess that I don't understand expressing lighting in f-stops. I've seen it referenced this way before. Can anyone point me where to get a grasp on that?

The concept is pretty simple when explained the right way... Not that I'll explain it the right way, but I'll try...

Think of how bright a given light is. We *can* measure the brightness with a light meter, but not a lot of people have a meter or way to do that. So rather than worrying about how bright the light is, think of it as what aperture setting is needed to allow a "medium" amount of light for the picture.

Now imagine two different light sources on a set. With one on and the other off, let's say that the proper aperture for that light was f/5.6. Turn off that first light and turn on the second. But that second light is brighter than the first. To get a properly exposed picture, you needed to stop down the aperture to f/11.

Regardless of how many lumens or lux or footcandles or watt/seconds, we can describe the second light as being 2 stops brighter than the first (because we stopped down the aperture by 2 stops).

Now if the lights were continuous lights, we could (alternatively) made the shutter faster by two stops and gotten the same effect. However, we're usually describing light this way when using non-continuous light. The shutter becomes less useful with non-continuous light. It's either aperture or ISO speed. This terminology has been around for a while, back in the days of film. Because you'd load the camera with a particular film speed, and wouldn't likely be changing it, that makes the ISO variable irrelevant.

So it all comes down to describing the brightness of light as how we control the brightness with the aperture.

Putting this to m.good post (#15), he said to put the main at f/11. However bright that is doesn't really matter it's just a relative measurement. The fill light, behind the camera was set at f/4. That means that we'd have to open up the aperture by 3 stops to get the same brightness. Or, the fill light is 3 stops weaker than the main.

If the difference were only 1 stop, then there's low contrast between the main and fill. When the number of stops is high (3, 4 stops) then there is more contrast and the image is more "moody" with light/dark.

Left Handed Brisket wrote in post #18227884
Do you have a light meter?

No I do not. It would probably help me understand things better if I did.

Wilt wrote in post #18227889
Exceedingly simple concept...

Example 1:

Meter one light, get something like 1/60 f/4; meter other light, get something like 1/60 f/2.8
f/2.8 vs. f/4 is -1EV (second light is weaker than first light by -1EV)

Example 2:

Meter one light, get something like 1/60 f/5.6; meter other light, get something like 1/60 f/2
f/2 vs. f/5.6 is -1EV (second light is weaker than first light by -3EV)

In Post 19 I deliberately chose Distances which were numbers like folks are accustomed to seeing for f/stops...most folks do not understand a concept that if I move a light from Distance A to Distance B, the intensity of the light behaves much like f/stop distances...moving light from 4' to 8' means the light on the subject is -2EV weaker at the farther distance!

That helps. I understand how intensity of the light behaves much like f/stop distances. Thanks!

dasmith232 wrote in post #18227898
The concept is pretty simple when explained the right way... Not that I'll explain it the right way, but I'll try...

Think of how bright a given light is. We *can* measure the brightness with a light meter, but not a lot of people have a meter or way to do that. So rather than worrying about how bright the light is, think of it as what aperture setting is needed to allow a "medium" amount of light for the picture.

Now imagine two different light sources on a set. With one on and the other off, let's say that the proper aperture for that light was f/5.6. Turn off that first light and turn on the second. But that second light is brighter than the first. To get a properly exposed picture, you needed to stop down the aperture to f/11.

Regardless of how many lumens or lux or footcandles or watt/seconds, we can describe the second light as being 2 stops brighter than the first (because we stopped down the aperture by 2 stops).

Now if the lights were continuous lights, we could (alternatively) made the shutter faster by two stops and gotten the same effect. However, we're usually describing light this way when using non-continuous light. The shutter becomes less useful with non-continuous light. It's either aperture or ISO speed. This terminology has been around for a while, back in the days of film. Because you'd load the camera with a particular film speed, and wouldn't likely be changing it, that makes the ISO variable irrelevant.

So it all comes down to describing the brightness of light as how we control the brightness with the aperture.

Putting this to m.good post (#15), he said to put the main at f/11. However bright that is doesn't really matter it's just a relative measurement. The fill light, behind the camera was set at f/4. That means that we'd have to open up the aperture by 3 stops to get the same brightness. Or, the fill light is 3 stops weaker than the main.

If the difference were only 1 stop, then there's low contrast between the main and fill. When the number of stops is high (3, 4 stops) then there is more contrast and the image is more "moody" with light/dark.

That helps too. Thank you!

I went to a workshop that helped me understand how shutter speed becomes less useful with non-continuous light. The point about film is, with no adjustable ISO, is very interesting too!

Did fairly well with it last weekend. 34 inch softbox at about 45° down angle and 45° side angle. But if I needed much fill from a front angle I started getting shadow.

KatManDEW wrote in post #18241990
Did fairly well with it last weekend. 34 inch softbox at about 45° down angle and 45° side angle. But if I needed much fill from a front angle I started getting shadow.

Sample shot? Just want to see that shadow. Thanks.

bobbyz wrote in post #18244993
Sample shot? Just want to see that shadow. Thanks.

Here's an example. The dark hair and jacket were pretty dark if I didn't add some front fill. Also ended up with some shadow from her nose. And I frequently get significant cheek shadows.

Edit: The backdrop shadow isn't near as visible here in my browser. And as usual, the photo is more saturated than when viewing in Photoshop. I'm using a calibrated NEC monitor, and I convert to sRGB with Save For Web.

Just to toss another dimension to the thread, you can change the color of the shadow. Change it to any color you like. Can make the pic interesting.