This is the last in a series of star photography articles. In prior installments, Aim for the Stars covered techniques for photographing star points, whereas Hot on the Star Trail described a digital process for capturing star trails. The material covered in these earlier articles will not be repeated here, so I encourage you to reference them as needed.
In the context of night photography, I also recommend a recent article posted by Jim Salge. In Viewing and Photographing the Northern Lights in New England, Jim explains why and when it may be possible to capture the Aurora Borealis not far from home.
Milky Way over Albany Bridge
Single frame: 30-secs 14mm f/2.8 ISO 2500
Bridge lit for 5 secs using incandescent light
In previous installments, I stayed clear of foregrounds. Instead, the focus was more on capturing the stars themselves and much less on the surroundings. But as we know, a good foreground is an essential piece of the picture, and images involving the stars are no exception to this bit of wisdom. So, this article will focus on the challenge of adding foregrounds to your star images.
Choosing a night composition shares many similarities with daylight photography. Placement of the horizon line, use of the rule of thirds, and separation between photo elements all remain relevant factors. But the nighttime introduces one more compositional challenge: the foreground must be visible despite the lack of sunlight.
Without sunlight, there are two options for shedding light on your foreground: natural light or artificial light. On a moonlit evening, the natural light emanating from the moon may be sufficient to light the foreground, even when it appears dimly lit to the naked eye. One of the inherent properties of long exposures is that they intensify the light, so check your LCD and histogram to verify the effect of moonlight on the foreground.
Full Moon at Foster Bridge
Single frame: 20-secs 24mm f/3.5 ISO 640
Bridge lit entirely by the light of the moon
If you happen to be shooting on a moonless night, then the foreground will have to rely on artificial lights of some kind. The ambient light from a lighthouse, car headlights, and lampposts are all possible sources of artificial light, albeit difficult to control. Check your surroundings to see if existing lights from the environment can satisfy your needs.
When the environment makes no contribution to lighting your foreground, then you need to furnish your own artificial lighting to do the job. I always carry two small (yet powerful) flashlights in my camera backpack: an LED flashlight and an incandescent flashlight. I tend to use the incandescent light more often than the LED light because I find the warmth of incandescent light more natural. But when I need to light a structure like a white-steepled church or a white lighthouse, then I will surely use the LED flashlight instead.
PAINTING WITH LIGHT
Light painting is a broad subject (sometimes involving lasers), but here I limit the scope of the discussion to painting natural foregrounds in our star photos.
You may wonder how long it takes to paint a foreground in the dark. The answer depends on the size of the subject in question and its distance to the camera. The smaller and closer the subject, the less time it will take to paint it. On the other hand, if the subject is larger and more distant, then it will take more time to light it properly.
Adam on Foss Mountain
Single frame: 30 secs 14mm f/2.8 ISO 2500
Rocks lit for 3 secs using incandescent light
In general, I find that many subjects can be painted in less than five seconds. This means that you will only need to paint the foreground during part of the exposure. For example, I may paint the foreground for the first three seconds and then turn off the flashlight. The key to success is to experiment. Expect to repeat the process many times until you find one that looks good.
Steady hand motion is important for painting evenly. Paint strokes work well, as long as you cover the surface without leaving gaps. To avoid the gaps though, I often apply a circular motion instead of strokes. To do this, wiggle your wrist in small circles once over the whole foreground. Note that light painting must be done at a consistent pace, otherwise ugly hotspots will appear on parts of your foreground. If you see hotspots, try another pass or shorten up the painting time.
If you want to take light painting a step further, try painting with colored lights. I sometimes carry a Gerber flashlight equipped with red, white, blue, and green lights just for fun. The resulting photos may never make it into my portfolio but are a fun way to push the creativity envelope. Alternatively, colored gels affixed to an LED flashlight can render similar effects.
Kettle Pond with Red Jetty
Two frames: 30 secs 14mm f/2.8 ISO 4000
The jetty was lit for 2 secs using red flashlight
If you are able paint your foreground and capture perfect stars in a single frame, count yourself lucky. Night photography often involves blending multiple exposures to produce the envisioned result. The reasons have to do with exposure and depth of field.
Exposure can be a problem when your camera is unable to capture the dynamic range of the foreground and sky in the same frame. For example, a dark sky with a foreground brightly lit by nearby lamps can result in an over-exposed foreground. In such cases, the solution may be to shoot one frame for the sky and another for the foreground, blending the two photos in post-processing to balance out the exposure.
Depth of field comes into play when the aperture setting cannot render both the stars and foreground in focus. In the preceding articles, we saw that the stars are usually shot with the aperture wide open, meaning the widest aperture possible for the given lens. This works well to avoid noise, but it can cause near foregrounds to appear blurred. Here again, the solution is to shoot a frame with the focus set on the stars (at infinity), and a second frame with focus set on the foreground subject. Once the two frames are combined in post-processing, both foreground and stars will appear in focus.
Combining multiple exposures involves Adobe Photoshop, Adobe Photoshop Elements, or Adobe Lightroom with the onOne Perfect Layers plug-in. Bret Edge has written several good tutorials on the art of blending frames, while photoFocus gives a nice introduction to focus blending.
Nubble Light under the Stars
Two frames: 25 secs 17mm f/4.0 ISO 1000
The rocks and water were lit by the lighthouse
I think star photography is best approached with an open mind and a childish eagerness to experiment. While literally operating in the dark, trial-and-error becomes an intricate part of the process. So yes, it does require time and patience. But it seems to me that the element of unpredictability is what makes star photography so much fun and so addictive.
I hope you learned something useful from this series, and wish you the best as you endeavor to put your own personal spin on star photography. Above all, stay safe and have fun.