White Seamless Tutorial :: Part 2 :: Setting Lights & Exposure
We are now going to look at setting up a simple headshot on a pure white seamless background, or, “BG” for short during this tutorial. Click here for Part 1 of this tutorial.
The philosophy I have when shooting on pure white is that I want to light the BG and the subject independently from each other. Meaning; The light on the subject isn’t making a change to the exposure on the background and the light on the background isn’t making a change to exposure on the subject. As I talked about before, those cutters on the sides of the set are key to making this happen. The next consideration is keeping the subject a fair distance away from the background as well. In this first example my subject, Thomas, is about 11 feet away from the white seamless hanging behind him. The closer he gets to the background, the more likely it is that light reflecting off of the seamless is going to add exposure to him in the final image. The further I get my subject away from the seamless, the less light coming in from the background will get to him. I’ll talk more about that specifically in a bit.
For the sake of being as technical as possible for this tutorial I have wiped the dust off of my light meter and put it back into use. I rarely, if ever, pull it out when setting up this type of set simply because I’ve done it so often and I know what I’m looking for when I chimp. If you have a flash meter already, good for you! Pull it out and put it in the incident mode. If not, I’m going to give you examples of the visual clues I am looking for when I’m shooting so I know how to adjust my lights without using a flash meter.
For this set up I have two lights on the background. One on each side. I also have barn doors on these lights in addition to using the bi-fold cutters. Since my ceiling in here is so low and those white walls are so close to the set I use the barn doors to flag light from the BG lights off of the ceiling and walls. The light on camera left is pointing just left of center of the BG. Camera right light is just right of center of the BG. I want an even spread of light across the BG so that if I were to take meter readings from the left edge to the right edge of the seamless, I would get identical readings from edge to edge. If your BG is within a quarter stop from edge to edge you’ll be fine. If your BG has more than half a stop difference from edge to edge, position your lights in such a way to even that exposure out. If you don’t have a light meter, eyeball the dang thing and go for it.
For those of you new to lighting I am only going to be talking about exposure in terms of f stops. Shutter speed controls ambient light exposure and aperture (f stop) controls flash exposure. The ambient light in this scenario means nothing to me since I’m lighting everything with flash so my shutter speed is always going to be near my sync speed of 250th of a second. If you don’t know your sync speed you’ll have to RTFM. If you don’t know what RTFM is then you’ll have to Google that and ROFL. If you are lost on ROFL… how did you even get to this web page? Colon right parenthesis.
Also, these are always shot at my lowest ISO setting so that I have the cleanest images. No need to shoot this stuff at high ISO settings especially if you have some decent power coming from your strobes. If you are doing this with hotshoe flashes there can be occasions you need to up your ISO a bit.
For the subject I have one light source. For this particular shot I’m using a Westcott 50″ Apollo softbox. The light inside of the softbox is set to 100 w/s (watt seconds). For the pure white BG it doesn’t really matter what kind of modifier you use. Like I said, I’m lighting my subject independently from the BG so I choose my modifier based on the kind of light I want on the subject. You can use straight flash, an umbrella, a grid spot, a beauty dish, etc, etc. Actually, my favorite these days is a beauty dish. I just love that thing but for this, I chose a big softbox.
From my meter I’m getting a reading on my subject of f8 from that softbox (main light). To make that white BG pop I know that I need to have the BG at least 1.5 stops hotter than the subject. My target then is to get the BG reading to be f 11.5 because my main light on the subject is f 8. I’m going to expose for the subject at f 8 once I shoot a frame. I don’t really want the BG to be any more than 1.5 stops hotter than the subject’s reading. You’ll see why in the examples below. f 8 on the subject and f 11.5 on the BG is my standard set up. You can set the ratio anyway you want it. If your main is f 2.8 then you want the reading on your BG to be f 4.5. If you get f 5.6 on your subject then you want the BG to be at f 8.5. Nerd note – If the EXIF data is still in these images and you’re reading it you’ll see I actually exposed at f 9. My meter is about 1/3 of a stop off from my camera.
Let’s look at a properly exposed image first ::
In the image above I have a nice white background, no significant amount of flare coming back into the lens, no chromatic aberration (CA) around the edges or in the hair, a good exposure on Thomas, and I’m getting just a bit of “wrap” on the shadowed side of his face.
For that “back of head” reading I took my meter and placed it at the back of his head and pointed it toward the white seamless and took a reading. This is measuring the amount of light coming back to the subject from the BG. The more light coming back, the more wrap, and possibly more flare, you are going to have on your subject. That “wrap” is seen as a highlight on the camera left side of his face. That is coming from the light reflecting off of the white seamless. Some folks HATE wrap and work to eliminate it. Some folks like to have more of it. Personally I go both ways. Country AND Western.
There are times I want it eliminated. Maybe I want a really deep shadow on the side of the subject’s face. Lighting wrapping in from the back would fill that shadow in too much. Another example of the need to eliminate the light wrapping around your subject is when you are shooting someone wearing pure white. I want to keep a very clean separation of white on white. We’ll see that coming up in a minute. Sometimes I love to have more wrap because it accentuates the subject’s facial features. Most of the time though I’m fine with just a bit of it. The wrap above is something I won’t say cuss words about and I won’t lose any sleep tonight because of it.
If you want less wrap, move your subject further away from the BG but keep the same 1.5 stop exposure ratio from subject light to BG light. If you want more wrap, move your subject closer to the BG while still maintaining the 1.5 stop exposure ratio.
For those of you without a flash meter here are some examples showing you when your BG lights are over or under exposed. These are shown with the idea of you have a good exposure from your main light on your subject. Find that exposure first by turning off your BG lights and shooting a series of images of your subject with just the main light on. Remember, we are lighting the subject independently from the BG. If you have this set up correctly then you can take a shot at the proper exposure of your subject with the BG lights off and then with them on and your subject will remain properly exposed in both images with the exception of some wrap coming in from the BG when those lights are turned on. Make sense? No? Shoot pictures with your BG lights off and find the right exposure on your subject from the main light. Then turn on your background lights and adjust the power of those up or down to get a clean white BG.
Here is an example of when your BG gets too hot and starts giving you problems.
I had set my main light on my subject and got a reading of f 8 from it. With my BG lights cranked all the way up to full power I’m now getting so much light off of that BG that it added a stop to the meter reading of my subject. I suspect that the face of my softbox was even acting as a reflector to help add to that extra stop of light coming in the front. Looking at the image above it is pretty evident that the BG lights are set too high in power. Look at all the flare coming in over his shoulder on the camera left side of the frame and look at the overall loss in contrast in the image. I talked in the previous post about some lenses work better than others. My 50mm 1.8 lens shoots images that look like this on a properly exposed set. So if you are dead sure confident that your light ratios are correct and you get that much flare and loss of contrast, try another lens.
Here is an image with the BG underexposed.
There is nothing wrong with the image above here. In fact, you may want some density in your BG from time to time and we are going to talk about that in the next part of the tutorial. BUT… we are talking about setting your BG exposure properly to get a PURE WHITE background in your image and that BG ain’t white. If that is your image and you want it white, the curse words show up in post production. If this is what you are getting then you simply need to up the power settings of your background lights.
Two additional things to look at in this under exposed BG image :: Notice the lack or wrap coming in from the BG and how much darker the shadow on the camera left side of his face is. Also notice that my lights aren’t set to give me a dead even exposure across the width of the BG there. One side is a bit hotter than the other. Each light is set exactly to the same power setting but the camera left side is a bit hotter than the camera right side. This is a visual indication that I need to change the position and/or direction of my BG lights so I’m getting even light across the BG. It isn’t that big of difference here. But it is noticeable and there are times when I want density in that BG and I want it to be perfect from edge to edge in continuous tone. Again, we’ll talk about that in the next part of the tutorial.
Once you nail your exposure and everything is set correctly, you can shoot someone wearing a black shirt on a white background and have them switch to a white shirt on a white background and shoot the same exact exposure and maintain separation.
Let’s take a look at a series of images with the lights in different states of being on or off.
See that second image in the series where there is a tad bit of light hitting the front of Thomas? That is light coming off of the BG, hitting the ceiling, and adding a slight touch of exposure to the front. If I had taller ceilings and / or my ceiling was black, I would have more of a silhouette there. I’m seriously considering painting my ceiling black but I haven’t decided if I really want to stay in the space beyond my lease. I want a cyc wall again damn it and I’m not going to build one here! Anyway……
Also notice the “all lights off”. I wasn’t shooting in pitch black but an exposure of f 9 @ 200th of a second at ISO 100 made a black frame because the studio is not that dark but not bright enough to have any ambient exposure come into the final frames I’m shooting. If I had some really hot spot lights on the BG or a bright window near my set we may see a little something in that image but not much. Once those strobes fire it would kill that kind of ambient light. So changing your shutter speed all up and down here doesn’t matter. Just set to your sync speed and adjust exposure on your camera by aperture only. You further change exposure by changing power settings on your lights…. but to reiterate. At camera level… set to your sync speed and just adjust f stops.
So that’s a basic headshot. You don’t have to have a roll of seamless for this application. Any old white or off white wall will do. Let’s look at a full length next. I’m going to cry 7 tears and say 3 or 4 cuss words as I visually take you back to my last studio with the big cyc wall. That thing was bigger than my house. Developers came in and bought the place up and I can have it again in a few years at 3 or 4 times the cost per square foot once they pimp the place out and do stupid things to it. Like… Bring it up to code and stuff and take the lead out of the water.
I pull this off in the new space pretty easy until I have a band of 4 or more in front of me and I’m restricted to the 9′ width of white. It can be done with only moderate cursing. I’ve shot a family of 7 on a 9′ seamless before. For now let’s look at just shooting a full length of one person. Here is the back of the set.
This is what the back of the set looks like. Notice that straight shadow line the bi-folds are making. I keep my subject in “the shade” of the bi-fold doors so to speak. Also note that I hang the tile board out into the BG light area just a bit. The BG lights blow that little edge out so it isn’t seen in the final image and I don’t have to go into Photoshop to remove the hair line it creates if I don’t have it hanging out in the BG light.
Here is the front of the set.
Note that without that tile board, the white floor area is grey. Getting a subject standing on white paper and shooting a full length shot so that the floor and the BG are all white is a pain in the arse. You can do it but it’s a different way of lighting that I just don’t do. Call me lazy but $20 worth of tile board makes life easy. And no… those Home Depot work lights in the back are not being used on this set. This is three lights firing. Two on the background and one on the subject.
Let’s add a subject and a big industrial fan.
I show the image above to give you another glimpse of what the floor would look like without the tile board. It would be grey right up to the shadow line the cutters are creating from the BG lights. The tile board acts like a mirror in that you are seeing a reflection of the white BG in it.
Here is an image straight out of camera with only adjustments being made to color and contrast.
Clean. Simple. Effective. Done right on set and in camera so I don’t have to cuss like a sailor in post production. Notice the good separation of the white dress on the white background. Notice the nice little wrap on the camera right side of her face. I really like the wrap here and would not have worked to eliminate it. It was just enough to have some wrap but not enough that I lost the edge separation of the dress.
That wraps up Part 2 of the tutorial. Thanks to Thomas for being my exposure subject today and thanks to ya’ll for the comments and links and all that so far! Once I finish this tutorial I’ve got something kind of cool planned for all of you.
ETA – If you have questions about any of this, drop them in the comment section here on Part 5 of the tutorial. I will be following up on this tutorial with a new post answering all the questions at once.