Sunday, March 12, 2006

Sunday, March 05, 2006

Fun in the Dark by Andy Heatwole

Fun in the Dark
by Andy Heatwole

Category: Shooting Technique

Introduction

Not that long ago, night photography and long exposures in general required the use of film. However, today's high-end and prosumer digital cameras are more than capable of producing quality images at night. Exposures consisting of many minutes or hours are still film's domain but with some simple digital tricks, we can extend the camera's capabilities in this area quite a bit.

So what's the difference between night photography and day photography? No, it's not a trick question. When I take a photograph during the day I'm reasonably sure of what that image is going to look like. Not so at night. Clouds dance, lights streak, water blurs, and flashlights become paintbrushes. It's a great time to be out and it gives you an excuse to stay up late.

The ability to shoot digitally at night is truly a godsend because the image preview allows me to instantly see if my exposure settings are correct. With film, determining the correct exposure settings often required a good measure of luck on top of a whole lot of experience. For me, this ability to preview my shots has improved my night photography tremendously and made it a much more enjoyable experience. It also gives me much more freedom and incentive to experiment.


Moonrise over the ocean.

What You'll Need

A camera capable of taking long exposures. Most digital SLR's have a bulb mode setting that allows you to make exposures of any length you want. Even if your camera doesn't have this feature, as long as it has a timed shutter speed of 30 seconds or more you can still do a lot. My first digital camera had a maximum shutter speed of 30 seconds and I found that, while somewhat limited, it was still useful for most night applications. Also important is the ability to manually set the exposure. If you camera doesn't offer this feature you can still use it but you'll be somewhat more limited.

A sturdy tripod. This is an absolute must in night photography.

A shutter release. Sometimes called a remote switch, this handy device is basically a cable attached to the camera that duplicates the shutter button's functions. It allows you to take a picture without physically touching the camera which eliminates camera shake. This becomes especially critical in bulb mode where the shutter button must be continually depressed during the exposure.

A small flashlight. While not critical, it makes it a lot easier to see what your doing while adjusting camera settings. I have a LED key chain light that works great for me.

Basic Technique

Your exposure settings will vary greatly depending on your subject and available light. Personally, I try to shoot at ISO 100 to keep noise levels to a minimum but certain situations require a higher setting. If the scene you're photographing falls within your camera's metering capabilities or you have a hand held light meter, start with those settings and verify the exposure on the LCD screen (gotta love instant feedback). If not you'll need to experiment a little to get the correct shutter speed and aperture. Start off with an aperture that's fairly wide to allow more light to enter the camera. I tend to start off with an aperture setting of 5.6 and a shutter speed of 15 to 30 seconds. I know that 5.6 isn't exactly wide open but keep in mind that depth of field is still a factor. If you're shooting landscapes, which I tend to do, a smaller aperture will keep things nice and sharp.

After the shot, look at the image on the LCD screen. If it's underexposed, increase the length of the exposure or the aperture size. If it's overexposed, decrease the exposure time or the aperture size. I know this is a very rudimentary method for determining exposure but with experience you'll develop a feel for what exposure settings work best in various situations.

Painting with Light

Just as the title says, you can use just about just any light source to "paint" light into your images. I use a Mag flashlight because it allows me to adjust the width of the beam but any strong flashlight will do. Some people also use high powered spotlights which can be useful when illuminating distant subjects.

Personally, I like to perform this technique just before complete darkness which adds some nice ambient light to the scene. The exposure time for this technique will vary depending on the available light but generally 30 seconds to 2 minutes is sufficient.


This image was illuminated with only a flashlight.

Place your camera on a tripod and start the exposure. With the shutter open, move your flashlight in broad sweeping motions across the scene. You can try to paint the entire scene or use the flashlight to highlight certain elements. The amount of time required to illuminate a particular scene or element depends on the strength of the light and the effect desired. This is where experimentation comes in to play. Light painting is my favorite form of night photography because you never really know what you're going to get.

If your feeling adventurous, add some fire to your images but ALWAYS be careful. One way to do this is to tape a Zippo lighter to the end of an unraveled metal coat hanger. This allows you to move the flame throughout the scene without the risk of getting burned. Also, if you're fast enough, you can usually move throughout the scene without being exposed in the final image.


I used a Zippo lighter attached to a coat hanger to create the flame in this image.

Lightning

I'm fascinated by lightning and capturing it with the camera can be a thrill like no other. Fortunately, it's also very easy to shoot. The first rule of lightning photography is BE CAREFUL! Standing on your roof in the middle of a thunderstorm with a metal tripod is not a good idea and I know that now ;-).

I've always shoot lightning at ISO 100. This helps increase the time I can leave the shutter open to catch a strike before the ambient light overexposes the scene. I generally start off with my aperture set at 5.6 and an exposure of 15-30 seconds, depending on available light. If the lightning is close, you'll probably need a smaller aperture. If it's further away, open it up a bit.

Place the camera on a tripod and focus on an area where lightning is occurring. If a strike occurs near the beginning of the exposure, leave the shutter open a bit longer to expose for the ambient light. If it occurs near the end of the exposure, it's probably a good idea to close the shutter after the strike to avoid overexposing. If you're using a timed exposure, place the lens cap or your hand over the lens until it's finished. Remember, lightning is very bright (it's nature's flash) and will expose the entire scene very quickly. You can leave the shutter open to capture multiple strikes but you run the risk of overexposure.


These strikes were shot from my front porch.

The best storms are those that are very active and produce lots of lightning. This gives you a chance to get multiple shots and adjust your exposure settings as needed.

The Blue Hour

The "blue hour" is the period of time after sunset but before complete darkness when the sky takes on a deep, rich blue. To the naked eye, it can look almost black but the camera sees things differently. This is my favorite time to shoot because instead of getting a dark, featureless sky, you get one that's beautiful and vibrant in a way that's unique to this time of day. Unfortunately, the blue hour tends to be very short, especially in winter so you have to be ready for it.


A typical blue hour sky.

Extending the Camera's Capabilities

I've shot exposures of 5 to 10 minutes with my 20D without any problems. But what happens if you want shoot something like star trails which can require an hour or more? Well, you can go back to film or you can use a post processing technique called image stacking. This technique utilizes multiple shots of the same scene. For our star trails example, say you wanted to create the equivalent of an hour long exposure. You could shoot 60 one-minute exposures one right after the other which would give you an hour's worth of shots. You can then "stack" those images in a program like Photoshop to create the illusion of one continuous exposure.

Here's how it works. Open the first image in Photoshop or a similar image editing application. This will create our "base" or background image. Then, open the next image in the series. Copy this image and paste it into a new layer on the base image. Change the blend mode of the new layer to "lighten". This has the effect of only showing the pixels on the layer that are brighter (the star trails) than the layer underneath it. You've now created the illusion of a two minute exposure.

At this point you can close the image you copied from (make sure you leave the base image open). Then, open the next image in the series and repeat the process. As your star trails grow, you'll also notice the number of layers growing as well. I would recommend flattening the image after every 4 or 5 layers you add to keep the overall image size down. A good example of this technique can be seen here.

Additional Resources

If you need some inspiration or just want to see what's possible I highly recommend the Nocturnes website.

*****

Andy Heatwole lives in San Marcos, a thriving little town in the heart of the Texas Hill Country.

"I was inspired to get into photography about five years ago after seeing some night shots on the Internet. My father-in-law, a long-time photographer, supplied me with my first SLR a fully manual Minolta XE-7. Almost overnight, I developed a passion for image making. After learning the basics, I switched to digital and have never looked back. I enjoy all types of photography but shooting at night is still my favorite."

You can see more of Andy's work online at http://www.bluehourphoto.com

The Nocturnes Night Photography Web site

The Nocturnes Night Photography Web site

DurhamPortfolio - Photography by Kathleen Connally

DurhamPortfolio - Photography by Kathleen Connally

The best I've seen on the net.

Fairvue Central >> Bloggies >> Sixth Annual Weblog Awards

Fairvue Central >> Bloggies >> Sixth Annual Weblog Awards

The Daily Shooter - Photographer of the Month Kathleen Connally

The Daily Shooter - Photographer of the Month Kathleen Connally
Unbelievable. One of the best photographers I have ever seen.

Saturday, March 04, 2006