|A March Milky Way over Agathla Peak, Arizona - light painted from a distance of almost one mile ~ © Royce Bair|
NOTE: a complete list of Light Painting Tutorials can be found here on this blog (scroll down to see all of them).
Angle of Light: In order to achieve a three-dimensional effect for your distant feature, the light painting is best done from a somewhat perpendicular angle to the camera. Flat, uninteresting lighting happens when one paints from behind or close to the camera.
The Glare Factor: Powerful spotlights are so intense that they will light up any dust or moisture in the air and cause it to reflect back into the eyes of the one doing the light painting —so much that they can barely see the distant feature they are painting. When this happens, communication and feedback with the person at the camera position is essential in order to produce effective and even light painting. Over long distances, this communication is usually done best with hand-held two-way radios, equipped with VOX or voice-activated control.
Calculating the Exposure: Top NightScape photographers usually try to do their light paint during the exposure for the sky, or a single exposure that includes incorporates both the sky and the lighted foreground feature. This requires that the light intensity match the brightness of the sky. If the exposure for the sky lasts 30 seconds (i.e., f/2.8, 30 seconds @ ISO 4000), then the light painting time must be adjusted to match that exposure. If distances are short, and the intensity of the light is high, light painting time may be only 5 to 10 seconds. With longer distances, the light painting time may often need to be increased to the full 30 seconds.
In the case of the Agathla Peak photo, a 24mm lens was used, requiring a shorter sky exposure (under 15 seconds, in order to prevent star trailing). Because of the nearly 1-mile distance and the shortness of the exposure (13 seconds), the intensity of the light source had to be increased to the use of a huge, 18-million candlepower spotlight.
One can get closer to the foreground feature to reduce the need for a more powerful light source, but not too close. If you get too close to your feature, the portions closest to the light may burn out (too light), and the portions furthest away may be too dark in your light painting. By keeping your lighting distance about four times greater than the size of your feature, you reduce the light falloff ratio. (In this Agathla Peak setup, the 1,500-ft. feature required that I be about 6,000 feet away —I chose a modest compromise of 5,000 feet.)
One Exposure or Multiple? Even if one wants to produce the NightScape photo in just one exposure (hey, it's a pride thing), multiple takes or exposures will often be preferred in order to increase one's chances for success. Blending the foreground portion of several exposures (via Photoshop layers) will enable you to even out your lighting, especially as distances increase and the glare factor escalates.
Stay in One Place: In order to blend foreground portions later in post processing, you must remain in one place —otherwise your image portions will not register or align. Since sky conditions are also constantly changing, you'll also improve your chances for a successful image by staying put and not moving your camera or tripod. This will allow you to pick and choose the best skies to blend with the best foreground exposures.
|Staying in one place will increase your chances for a successful image combination of sky and foreground. Taken from page 105 of my ebook, "Milky Way NightScapes". (Click to enlarge.)|