Shoot a Smile With Your Umbrella
Before photography was invented, painters had their studios fitted with big north-light windows because they wanted their subjects lit by a large light source. Why? Today, every photographic catalog has a lighting section filled with big umbrellas and bank lights, both of which represent large light sources.
In fact, big light sources are so common today that almost everyone’s mental image of a fashion photographer includes lights flashing into big umbrellas; just look at any TV show or movie that features a fashion photographer taking pictures to prove my point.
The stereotype is so ingrained in our society’s concept of photographic lighting that even Felix Unger used them! Why? Because big light sources, often called “broad light sources” (be they a north light window, an umbrella light, a bank light, or even a flash bounced off the ceiling or a wall), create beautiful light and flatter the subjects they illuminate.
You too can use a broad light source to both impress your photographic friends and get rave reviews from your subjects! Understanding why this is true and putting that knowledge to work can make your pictures better.
Gift Wrap? Soft Light?
Experienced photographers will tell you that big light sources “wrap around” the subject they are aimed at, or that they put out “soft light”. But, can you really use a big light to cover and decorate a holiday gift? Is the light from a broad source really soft like a cotton ball or a marshmallow? Of course not!
Because light rays only travel in straight lines they can’t really wrap around anything, and soft lights are neither cotton balls nor marshmallows–but there is some truth in these claims.
What these photographers are trying to put into words is how a big (or broad) light source differs from a little (or point) light source. That difference is best exemplified in the shadows they create. Now look at sketches #1 and #2. They trace light rays coming from the far edges of both a broad source (a 55-inch umbrella is depicted in sketch #1) and a point source (a typical 2×3-inch flash is shown in sketch #2) with both illuminating a 12-inch human head from the side. Importantly, both light sources are five feet from the subject (but in umbrella sketch, #1, the distance is measured from the center of the umbrella’s surface and not from the light source) and the two sketches are drawn to the same scale.
In both instances, I used a red pencil to fill in the shadows created by the subject from each light source. Notice that the size of the broad source lets its edge rays (which are always straight) reach further around the subject so, in a way, the broad source does “wrap around” the subject but it’s not because the light rays bend or curve.
Umbra and Penumbra
Not only does a broad light source make smaller shadows than a point source light, but also the edge of the shadow’s pattern is more graduated than the edge of the shadows from the point source. This edge of the broad source’s shadow pattern is often termed “softer” (than that of a point source) and that is why broad light sources are sometimes called “soft lights”.
A shadow is made up of two parts called the umbra and the penumbra. While the umbra part of a shadow is the total absence of light, the penumbra is a lighter part of a shadow that is partially illuminated. Point source lights have a very small penumbra (basically irrelevant in real-world situations) but broad light sources have a much larger penumbra.
It is this larger penumbra that makes the shadow’s edge more gradual (softer) and this is what helps minimize the subject’s flaws. Look at sketch #3 to see where the penumbra is. Sketch #3 is the same as sketch #1, but this time I have defined the penumbra and shaded it in turquoise while leaving the umbra shaded in red.
So What?
To illustrate just what this means in a real-world situation I cut the eraser off a pencil and glued it to a white card. I then took a picture of the eraser with the 55-inch umbrella light and the 2×3-inch point source light using the same dimensions (only full-sized) that I used in the sketches. Bearing with me for a moment, let’s make believe the eraser is a huge pimple on your subject’s forehead!
Accepting the fact that this would be a very big pimple in real life, notice how the broad source light minimizes it and the point source light accentuates it. Interestingly though, note that it’s the shadow each light source creates that calls more or less attention to the pimple… I mean …eraser. Now, scroll up and take a look at sketches 1 and 2 to better understand this effect.
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| A broad source shadow… note the penumbra! | A point source shadow. |
Natural Broad Sources
Even if you don’t work with photographic lights or flash units and prefer available light, understanding these concepts can improve your photos. Remember that the sun (definitely an available light!) is a point source while the sky is a broad source. That’s one reason why so many pros (including myself) look for open shade when shooting outdoor portraits.
The sun offers better, more natural, color than the bluish sky, but by adding a warming filter over your lens (such as an 81A or 81B or adjusting the white balance on your digital camera) you can take care of those open sky blues. By placing your subject in the shade you’ll end up with photographs that both you and your subject will enjoy more.
Another example of a naturally occurring broad source is the sky on a cloudy day when the sun casts no distinct shadows. Like open shade, cloudy days are also bluish in color but the warming filter(s) mentioned above can take care of this in a jiffy. In fact, if you use a warming filter and are careful not to include the sky in your background this type of light is amongst the most flattering for people’s pictures.
Indoors there is window light, and when the sun isn’t shining directly through the window, it is a pleasing broad source that can be found almost everywhere! As a hint here, remember that windows with a northerly exposure never have sun shining directly into them and sometimes, subjects lit by a north light window can benefit from an 81A or 81B filter also.
Conclusion
Once you know that there is no direct sunlight (a point source) shining into north-light windows you’ve discovered the reason why painters almost always had north-light windows built into their studios! Some of you will remember that this thought was mentioned at the very beginning of this column so we have now come full circle and it’s time for you to buy, create, or find a broad source of your own and start making beautiful people pictures!
