This time I would really like to expand knowledge about light. I see how people use light in photography - outdoors, in rooms or in studios. And for me personally, I love the studio space and filling it out with the light that I need. It gives me ultimate control for the mood, theme and bringing out the best side of the model. From a physic standpoint, I know what light is but from the artistic waypoint, I'm still learning. I remember that one of our photography teacher suggested taking painting classes to understand the light and after that, I started watching painted art in a different way.
WHAT IS LIGHT?
Visible light to the human eye is an electromagnetic wave. Its wavelength is 380-740 nanometers (nm) and on all the light spectrum it is located between infrared (with longer wavelengths) and ultraviolet light (with shorter wavelengths). Actually the light that is visible to the human eye is a tiny part of all the light spectrum.
Light travels in a room with a certain speed which means that it takes time to light get to a certain destination. Light travels usually in a straight line and approximately 300 000 km/s in a vacuum. In different environments light speed changes - in water, it's approx 225 000 km/s or in the glass, it is 200 000 km/s. All forms of "light" (electromagnetic radiation) move at exactly the same speed in a vacuum.
Light particles are called photons and the amazing thing is that the Massachusetts Institute of Technology (MIT) has created a camera that captures it. That means that the camera shoots one TRILLION frames per second! With little math, we can get one exposure for every .3 millimeters (300 micrometers) the light travels.
Speed of light: 3.0 x 10^8 meters/second
Speed of camera: 1 x 10^12 exposures/second
Do some dimensional analysis to find that: we are getting 3.3 x 10^3 exposures per meter.
Okay, that may seem too much math and bit geeky, but photography is built upon it and is possible because of light and light only. Without light, there would be no photography, and knowing light makes your photography much better - especially in the studio. Of course, there is no need for complicated mathematics but there are few formulas that can be useful.
LIGHT IN PHOTOGRAPHY
There are two types of light:
natural light - in that case, the light source is the sun
artificial light - in that case, light is created usually by human: candle, bonfire, incandescent lamp, strobe
All the light is characterized by color temperature or as we know it camera White Balance and it is measured in Kelvins (K). Color temperature is a characteristic of visible light that has important applications in the lighting of photography and videography but also in publishing, manufacturing, astrophysics, horticulture, and other fields. Lower the temperature the yellower the environment and higher the temperature more blue-ish the environment. It might be confusing the fact that "warm" lighting in this sense actually has a "cooler" color temperature that often leads to confusion.
Here are some of the light sources Color Temperatures as reference.
1700 k - candle
2500k- 40w incandescent lamp
3000k - sunset
3200k - photo halogen lamp
5000k - midday sun with clear sky
5500k - flash or studio strobe
6500k - cloudy midday
7500k - clear day in the shadow area
12 000k - dawn
These are just reference points on what to consider while shooting in different environments. Also, have to take in count reflections and specifics of the equipment you are using. For example, different studio strobes color temperature may vary. With cheaper strobes, the color temperature may even vary after every shot.
The best way to get the exact color temperature is to use a lightmeter or color chart.
REFLECTING A LIGHT
Different surfaces reflect light differently - lighter surfaces reflect more than darker ones. It may be intentional or unintentional. Intentional can be reflectors, styrofoam sheets. Photographers turn strobes to a wall or ceiling to get softer light.
You can buy small reflectors that are designed for on-camera flashes. Problems usually appear when we have unintentional reflections - from building/car windows or even from plants in the park (color cast). You can avoid them or use them in a creative way.
SHADOWS
With light comes shadows. Shadows can be useful or distracting - it all depends on the context or what outcome is in mind. For commercial fashion shoot, shadows with only top light may not seem flattering but for a horror movie poster, the same light scheme may work well. We get the shadows because light travels in a straight line.
There two kinds of shadows - full-shadow and half-shadow. With a big light source, we get those two types of shadows.
Shadow characteristics depend on light source types and distance from the subject. With strong harsh light we get strong sharp shadows. Diffused light makes shadows softer or even get rid of them.
CONCLUSION
Light is an interesting and fascinating subject. This here is a little introduction into the light and the first step how mold light the way you can get the desired outcome. I have seen how photographers with good lighting skills barely need any editing with their photos. For product photographers lighting a really reflective object can be very challenging. Knowing the physics of light and with few reflectors, you can make magic and it saves from a headache in Photoshop. Good lighting means that you have to spend less time in post-processing. The only way to get a better understanding of light is practice. There are some key components to follow but there is no way around it except doing it.
In future posts, I´m gonna talk about more about light and how to use it. It is a big wide and interesting subject which I'm greatly fascinated by it.