In the first article we discussed the important of diffusing light sources and matching color temperatures. In this segment we will discuss white balancing and light ratios.
The term “white balancing” refers to the process of determining a color’s hue in relation to the neutral colors in the image. White, gray, and black are the neutral colors. If an image is not properly “white balanced” then white colors generally have either a blue or pink hue to them, depending on whether the image is too warm or too cool. Ironically, a neutral gray is generally used as the basis for “white balancing” an image, thus the popularity of the gray card.
There are two ways to white balance an image: 1) pre-shot, or 2) in post-processing. The former is by far the most effective method. The latter uses a method in which a small credit card or smaller sized gray card is placed in an outlying area of the image that will later be cropped out, and then in Photoshop that gray card is the focal point for the software white balancing process. However, I find that not only is the software process method far less accurate, but too often stray light or reflected light finds the gray card making the software process even less accurate. However, if you camera doesn’t have a custom white balance setting, then by all means use this method, but try to keep your gray card in the same light situation as the subject as possible. Some people will clip a gray card on the subject’s shirt or pocket and take a photo, then remove it and take a 2nd photo… then use the first photo to white balance the second.
As I mentioned, customizing your camera’s settings pre-shot is the most effective way. Your camera’s manual will tell you how to do this. Generally you will set your camera on any non-custom white balance setting, then place a gray card in the subject’s position (or have your subject hold it) in a way that no light is reflecting off of it. Then you will focus it in your camera’s view finder so that it fills 50-75% of the frame (varies by camera model), and snap a photo. You then go to your camera’s MENU and find and select “CUSTOM WHITE BALANCE”. It will ask you to select a photo to be used for this setting, and you will select this gray card photo you just took. You then exit the menu, go back to your camera’s white balance settings, and select “CUSTOM WHITE BALANCE”. You are now ready to start your photo session, and every photo will be perfectly white balanced and you will have bright, accurate colors and perfectly natural skin tones.
With just a little practice, you will learn to customize your white balance in less than a minute. Now if you are shooting outdoors in the shade, and then move to a sunnier area, or into a pavilion — each light situation will have a different temp, and ideally should be custom balanced separately if you want to keep your photos looking their very best. You can find inexpensive gray cards in a number of different sizes and styles on Amazon.
Now that we are white balanced and ready to shoot, how do we manage light to get the best exposure. I will cover exposure itself in more detail in a third article, but this article will simply assume you are using the camera’s built-in point and shoot exposure calculations (camera sensors are not highly accurate, and if you are serious about good photography you will eventually want to learn how to calculate and set exposure manually).
So what does the term “light ratio” mean, and what does it have to do with exposure? First, it’s extremely important to understand that camera’s do not “see” or interpret light in the same way the human eye does? Have you ever been driving at dusk downtown, and the Christmas lights were all lit against the beautiful shadowy stone buildings — so you pulled out your camera and took a few shots, only to discover that in the camera images there were only glaring blobs of white light against a black background? This is because camera lenses “read” light far differently than does the human eye. Have you ever been driving at night and you are able to see barns, animals in the pasture, and have visibility of nearly a mile ahead, and then suddenly a car comes over the hill with its bright lights on, and suddenly you can’t see anything except for the light… this is because your eyes can’t adjust to the new “light ratio” fast enough… so as the lights become brighter, the shadows become darker.
To simply, just think in terms that a camera sees contrast more sharply defined than the human eye does. So often, lights/shadows that look fine to the human eye look terrible when developed on film (or in a digital camera). In fact, digital cameras are even more sensitive than film is, and color is more sensitive than black/white. So how do we know how to optimize lighting, and how can we control it in outdoor situations (sunny days, etc.)?
The optimal light ratio for most portrait photography is 1:3 to 1:4 — with b/w you might go to 1:5 for high contrast effects. I realize these numbers don’t mean much to you yet, and I may write even another article for more serious amateurs on how to use light meters, etc. to precisely calculate light ratios, but for now understanding what the ratio means will help you get better lighting even in your candid shots. Exposure is determined by the aperture setting of a camera at a given shutter speed. Let’s say our camera’s automatic sensor sets the exposure at 125/sec at f5.6 — if I were open the aperture to f4.0 (1 full stop) I would double the amount of light the lens would read. Conversely, closing down the aperture from 5.6 to 8.0 (1 full stop) would cut the amount of light in half. So the ratio is calculated by measuring the amount of light in the brightest areas (key light) and the amount of light in the shadow areas (fill light) separately, and then calculating the ratio. If the difference between the two meter readings is 1 full f-stop, then the ratio is 2:1 (twice the amount of light) .. if it were two full f-stops it would be a 4:1 ratio (twice the amount of light, two times = 4 times the amount of light).
Now, note that this is measuring light in terms of a light meter or camera sensor, not in wattage, etc. A light meter is ESSENTIAL equipment for a pro photographer, and highly recommended for serious amateurs. However, since quality meters are quite expensive there are some rules of thumb that you can use. Understanding those ratios above, you can figure if you place 300 watts of light on your subject at 35-40 degrees left of the camera position from 5 feet away, and place 150 watts of light at 40 degrees right of your subject from 10 feet away that you will be very close to the magical 4:1 ratio. Of course, if any light from either source spills over into the other light area it’s going to skew those numbers, so without a light meter, some trial and error will be required.
Even if you are just taking photos of your babies and toddlers at home, it is extremely simple to set up inexpensive lighting arrangements with just a couple of trouble lights, with daylight rated CFL bulbs, and some rip-stop nylon from the fabric store to use as diffuser panels over the lights. But what if we are taking outdoor photos at the park or at a family picnic? Ah yes..
Rule #1: The sun is your enemy!
Try at all costs not to take photos in the sunlight. You will never get a satisfactory result. Overcast days are the best days for photography, and even then look for shaded areas or shelters, because even light filtering through clouds is much brighter and intense to the camera than it appears to the human eye. The main difference between shooting outdoors and in a studio setting, is that the natural light of the sun is already providing our primary or “key” light, and there isn’t a lot we can do to adjust it short of finding a shaded area away from direct light. So you’ll want to position you subjects so that nature’s primary light is directed toward them from about 35-40 left of your camera position, just as you would do in a studio (never have your subjects facing the light – they will squint, and you will get “raccoon eyes” in the photo). Now comes experience and trial and error, but the trick is to use either our flash or reflector panels as fill light to soften the shadow side so the contrast isn’t too intense. There are several options for doing this:
- If there is a white or aluminum building or wall nearby opposite the direction of the natural light (ie. the sun is reflecting off it), you could position them a few feet from that structure, but where it’s still not in the frame and use the reflected light as your fill light. Often this is not an option though.
- You can buy emergency space blankets (which are like sheets of aluminum foil) for a couple bucks, and glue or tape them to a piece of cardboard to make a reflector panel. Then have someone hold it shiny side facing the subject from about 45 degrees right of the camera position. If you are in a shaded area where you get no natural light reflection, then turn the flash on your camera 45 degrees to the right, so the flash reflects off the panel. (NOTE: If you use on camera flash directly aimed at the subject, too much will spill into the key light area and will over expose that area, thus not fulfilling its “fill” function adequately).
- Minus those two options, your third option is to purchase a remote trigger and receiver (about $30) and move your flash off camera… either using a tripod, or having someone hold the flash, trigger it (with diffuser on) from a position of 35-45 degrees to the right of the camera.
With either of those options, without a light meter it will take some trial and error until you gain enough experience to be able to get it right — or at least close — in short order.
I know this all sounds like a lot to go through to take a photo, but if you practice good photo techniques they will soon become second nature and you will find that you can do them quickly. Good photography never happens by accident. Besides these are your treasures. They are worth a little time and effort, are they not?