white background: washed out pic

[brother7]

I'm having problems when shooting with all-white seamless roll. I feel that the model is getting washed out and my white balance is off, even though I do a manual WB. I light the background with 2 strobes with 7" reflectors. The background lights are metered about 2 stops over main (is this too much?). The final combined metering is about 2 2/3 over main. I try flagging my 2 background lights but still get a washed out subject. I think the light must be bouncing and wrapping around the subject.

My walls are white which might be contributing to the problem, so I'm thinking of buying some black bedsheets to cover.

Any guidance would be greatly appreciated.

all-white shot... does it look washed out to you?

[Arkie]

If you are using white seamless paper, you can usually get by with metering the background at about the same as the subject. I usually shoot with two white umbrellas bounced into the background from about six feet and then light the subject metered within a half a stop. The white walls are not your problem, though if you want more separation, you could cover them with a black or even gray cloth. Make sure your subject is as far from the background as possible to help in the separation also. I usually position mine about six to seven feet from the back wall. That is what works for me and has been working for 22 years. I can't show examples because I shoot primarily family groups and ladies wanting private pictures for their boyfriends, etc. No one wants to sign model releases. "Arkie"

[ChipBulgin]

How are you metering your background? The way to measure a background most consistently is to take a reflected meter reading from the camera position. Don't take an incident reading from the model's position. I don't know what meter you have, but most flash meters have a white or frosted dome/cover for taking incident readings. Sometimes this dome/cover replaces a clear disk, and sometimes is just slides out of the way. In either case, remove or replace the white dome/cover so that you can take a reflected reading. If your flash meter is also a spot meter, you're golden.

Taking incident readings of your background will result in over-exposure, because the meter is telling you what f-stop to use in order to achieve 18% gray at the meter's position. It tells you nothing about how much light is reflecting off of the background. The amount of light REFLECTED off of the background to achieve an INCIDENT reading that is 2 or 3 stops over your subject reading depends on the reflectivity of the background surface and how far the background is from your subject. But you will end up over-exposing the background significantly. What you think is 2 or 3 stops will probably be 4 or 5 stops. This appears to be the case in the image you posted. You're seeing reduced contrast due to overexposure.

What you want to do is measure how much light the background is reflecting, so use the meter as a reflective meter. And as I said before, measure from the camera position. This is MUCH easier if you have a spot meter, but just move the model out of the way while you meter your background if you don't have a spot meter. For white, get the background to reflect 2-1/2 to 3 stops more light than what your incident reading is for your subject. I find it easier to meter and set the background exposure first and then dial in the model.

Example: Measuring reflectively from the camera position, adjust the power of your background lights to give you an exposure of f/22. Once that is set, move your model into position and make incident readings and adjust the power of your subject lighting to give you an exposure of f/8 or f/9.5. Your background is now going to be 3 (f/8) or 2-1/2 (f/9.5) stops brighter than your subject.

-Chip

[brother7]

Thanks for the feedback guys.
I use a Sekonic L-358 flashmeter, which is incident-only (I think).

Arkie, how are you metering the background?

Currently, I take an incident meter reading with meter at background position, facing camera. That's a true incident reading, not a reflected reading.

I was an assistant before I started shooting my own stuff and recall that when shooting with a white seamless, I would stand at model position and point the meter towards the background. I also remember the photographer telling me to make sure the reading was about 2 stops over the main. That sounds kinda like what you're telling me, Chip. I'm gonna try this during my next shoot.

Here's a related question.... the new proposed technique of taking a reflected reading by standing at model position and facing the meter towards the background... is this a recommended technique for white backgrounds only, or for all colored backgrounds (for example, if i was lighting a gray seamless with colored gels)?

Thanks again for any response.

[glamourpics]

1. Sounds like you're putting way too much light onto backdrop. When incident metering, just a bit more than same incident exposure as w/ subject is plenty.

2. Color balance looks good.

3. One way to avoid flare from overlit background onto subject is to put black panels, facing camera, on each side of subject. This would cut off much of the extraneous light coming toward camera lens. And with subject being surrounded by bone white backdrop, you could easily in PS, make the white framing of the subject much larger.

Them's my thoughts. And experiences.

[R_Fredrick_Smith]

There are several factors here. First, 2 stops is too much. Usually about 1/2 to 2/3 stop more light on background than model is adequate. Second, you must insure that the background light does not overly spill on the model. Using umbrellas is usually going to spill some light if you are evenly lighting the background. So the best of all worlds is to light the background and then put gobos of some sort that block these lights from the model. Here is a lighting diagram and resulting photo to illustrate this point:

Re: white background: washed out pic 

As you can see there is no way for any spill from the background lights to hit the model.

As for metering you would just use incident readings for both background position and subject position while pointing the bulb at the camera. That let's you know the difference in the amount of light striking each position. You wouldn't want to do a reflective reading of one and an incident of the other since that will then be an apples to oranges comparison.

In the digital age, this is all much easier than it once was. Just do the above measurements. Set the camera to the fstop for the subject position. Have the subject stand there so you can focus. Now have the subject move away. Shoot the scene. Now look at the histogram of your camera. If you see a spike to the far right, then you have an almost white background. If you push the spike further to the right, it will be even whiter. How can you push it further to the right. Just put more light on the background. What if you see a spike right in the middle. Then you know that you're background will be a shade of gray (about 12% to 18% gray in fact). Do you start to see what is happening here. What it really means is you don't really need the meter at all, you can just use the histogram. By the way, if you set the brightness of your LCD display on the camera to around the middle, you'll get a better feel for the true lighting of the scene.

Cheers,
rfs

[n5wd]

Originally Posted by brother7

... I try flagging my 2 background lights but still get a washed out subject. I think the light must be bouncing and wrapping around the subject.... all-white shot... does it look washed out to you?

Look at the light on the left side of her face - you've got light from your background light hitting her directly (see the sharp shadow where her shoulder blocks the light on her cheek?). As others have said, in order to avoid that washed out look you have to:

1. move the model away from the background, and
2. block the background light from spilling onto the model.

A white background, lit evenly about 1/2 to 2/3 stop brighter than the model, will do what you're wanting, I think... and with less light bouncing around, it'll be a bit easier to control.
Here's the way I normally do it:

[ChipBulgin]

Originally Posted by brother7

Thanks for the feedback guys.
I use a Sekonic L-358 flashmeter, which is incident-only (I think).

Arkie, how are you metering the background?

Currently, I take an incident meter reading with meter at background position, facing camera. That's a true incident reading, not a reflected reading.

I was an assistant before I started shooting my own stuff and recall that when shooting with a white seamless, I would stand at model position and point the meter towards the background. I also remember the photographer telling me to make sure the reading was about 2 stops over the main. That sounds kinda like what you're telling me, Chip. I'm gonna try this during my next shoot.

Here's a related question.... the new proposed technique of taking a reflected reading by standing at model position and facing the meter towards the background... is this a recommended technique for white backgrounds only, or for all colored backgrounds (for example, if i was lighting a gray seamless with colored gels)?

Thanks again for any response.

The 358 comes with both an incident disk and a reflective disk. You should have a flat, black plastic disk with a little fresnel-looking circle in the center. That's the reflective disk. Look in your owner's manual and find the section on swapping out the disk. It's pretty easy to do.

The reason to measure from the camera position is because the brightness of your background as seen by the camera is determined by the inverse-square law. If your sensor (or film) is closer to the background, more light will strike it and make the background lighter. Further away equals less light striking the sensor and a darker background. Metering from the model's position won't give you an accurate reading unless your camera is in the same spot.

When making reflected readings, the meter is always going to assume that what you're pointing it at has the same luminance as middle gray, or Zone V in the zone system. So, to make it white, make sure the reflected reading from the background measures ~3 stops over the incident reading for your subject (f/22 vs. f/8). To make it black make sure the reflected reading measures ~3 stops under the incident reading for your subject (f/2.8 vs. f/8). If you want your background to have the same luminance as middle gray, make sure it meters the same as the incident reading for your subject.

With gels and a middle gray seamless you can make any color you want. Select a gel, red for instance, and change the power on your strobes (while keeping your aperture constant) to make it anything from blood-red to light pink. Just make sure to keep the light from your main, fill, and accent lights off the background so that they don't wash out the color.

Get into the habit of first figuring out what f-stop you want to use when shooting your subject. Then light your background with that f-stop in mind. You want to shoot at f/5.6 and have a white background? Meter the background from the camera position and set your strobes to deliver a meter reading of f/16. Then move your model into position and light him/her. When shooting a high-key background, move your model far enough away from it so that you don't get blow-back or wrap-around on your subject.

-Chip

[n5wd]

Sorry - was going to post an example of my setup and hit the wrong button... so here it is, based upon the diagram I showed in the previous message (except that the softbox is on the other side). No photoshop except sharpening... I'd normally even out the lighting towards the bottom of the frame...

This is Emily...

[R_Fredrick_Smith]

I think I remember that girl!

Re: white background: washed out pic 

The other secret to getting the white background is also in the RAW converter, when shooting RAW. Then you can simply use the exposure slide to set the white point to make the background pure white (even if the exposure and/or lightight was a little off).

Cheers,
rfs