Digital Photography 101 Low-light photography

Digital Photography 101

Low-light photography

Don't get caught in the dark — the basics of low-light photography

Just about every modern camera has some sort of flash, but that doesn't mean that you will get very good results by using it. Between the dreaded red-eye and subjects looking washed-out and pasty, you're generally much better off not using the flash at all. Taking good photographs in low-light situations without using a flash takes practice and a bit of technical know-how, but it can be done!

It's worth noting that "low-light" does not necessarily mean "nighttime" — we're using that term to refer to any situation in which the camera might decide it should use the flash. That could also mean indoors on a cloudy day, or under a thick canopy of trees, or at dusk or dawn. In part 1 of our low-light photography series, we'll discuss the basics of how to take good pictures when the lighting is less than ideal.

Take it off automatic

The benefits of taking your camera off automatic

The great thing about digital cameras is that they're pretty easy to use straight out of the box. Just turn yours on, set it to automatic mode, and start shooting.

But there's so much more to your camera than the automatic setting. Today's digital cameras generally have a range of different modes and settings that you can use, depending on what you're shooting. It's a little like having a professional photographer inside your camera!

These are the most common settings that you'll find on a modern digital camera. Yours might have fewer or more options, and the icons might be slightly different; be sure to read your manual to figure out exactly what you can do.

Flash Off mode
Just as it sounds, this mode simply turns off the flash and keeps it from firing, even if the camera thinks it's needed. Essential for times when flash photography might be prohibited, such as in a gallery or church; be careful to hold your camera as steady as possible, or use a tripod to avoid blur.

Portrait mode
The portrait mode is, not surprisingly, very useful when taking portraits of people. Using this setting will do two main things: It will adjust the camera's aperture to a wide-open setting, and it will make sure the white balance and image color are adjusted to achieve the correct skin tone. The narrow depth of field created by a wide-open aperture means that your subject will be in focus but the background will be nicely blurred, making your subject the center of attention.

If you take lots of photographs of people, Tecca has more tips on taking beautiful portraits.

Landscape mode
This mode adjusts the camera's settings to help you take the best photos of landscapes. Use this mode when you want to get as much of the scene as possible in focus at the same time, from your cousin standing in front of Mount Rushmore to the tip of George Washington's nose. It's great for mountains, beach scenes, cityscapes, and so on.

Close-up/Macro mode
The macro mode lets you take close-up photos of small objects. Depending on the camera, it will let you get much closer to your subject than normal while still keeping it in focus. This lets you fill the frame with the subject. The macro mode will also enable a very shallow depth of field, similar to the portrait mode.

Sports/Action mode
This mode is designed to make it easier to take pictures of quickly moving subjects: pets, children, sports —anything that's moving quickly enough that a slow shutter speed will result in a blurry picture. The sports/action mode will automatically choose as fast a shutter speed as the lighting will allow, thus freezing your subject's action into a (hopefully) clear photo.

Like to follow the action with your lens? Check out more tips from Tecca on action photography.

Night mode
One of the trickiest situations to photograph well is when the light is very low. The night mode, sometimes called the night portrait mode, helps make it a little bit easier. The camera will use a slow shutter speed to capture background details, but it will also use the flash to illuminate the subject. You should still use a tripod if possible, because even the steadiest hands will still shake enough to blur your background.

There are two other settings that are relative newcomers to the digital camera mode scene: Scene mode and Artistic mode. Depending on when it was made and how advanced it is, your camera may or may not have these options. Conversely, your camera may have only these options. Some cameras such as the Panasonic DMC-GF1 eschew the standard modes described above in favor of the greater options available in these two modes.

Scene mode
Selecting this mode usually opens up a different selection menu, most commonly displayed on the camera's LCD screen. From this menu, you can select the appropriate setting for the scene you are photographing. In addition to the standard options described above, you might find scenes such as candlelight (useful for indoor scenes like birthday parties), beach / snow (helps deal with very bright light reflecting off snow or water), and fireworks.

Artistic mode
As with the scene mode, this will open up a new menu that will allow you to choose from a variety of different artistic styles that you can apply to your photo, either before or after you take it. You can make your picture look like a line drawing from a coloring book, an old, sepia-toned photo, or a sketch made with colored pencil. This is sometimes called Creative Mode, and it will bring out the artist in anyone!

Don't be afraid to venture beyond the automatic setting on your camera. Just remember, it's easy to delete the pictures that don't work out, so there's no reason not to keep trying new things!

First things first: Take your camera 

off the auto setting. Auto is meant to be as general as possible, and it will assume that if the light is low, you want to use the flash. But as we've already discussed, you don't! So take the leap, be brave, and use a different setting. Which setting to use? The best solution will depend largely on the specifics of your scene. For now, just try using the flash off mode. This will probably be indicated by an icon that looks like a lightning bolt with a line through it.

What you need to bear in mind when using the flash off mode is that the camera will still try to choose the best settings for the light that you have — but more often than not, it won't choose correctly. By default, if you simply turn off the flash, most cameras will adjust to a much slower shutter speed to accommodate the lack of light. If the shutter speed it chooses is too slow, the resulting image will likely be blurry.

How do you prevent this from happening? Check your camera's display — it will tell you what shutter speed it's using. If it's slower than 1/60th of a second, then you should either adjust your settings or use a tripod.

Use a tripod
One of the things we've mentioned many times is that a tripod is essential when you're shooting in less-than-optimal conditions. The most steady-handed human can't hold a camera still enough to get a sharp image at shutter speeds slower than 1/30th of a second. 1/60th is a much safer bet. If you're using a larger, heavier lens, however, you'll have to use an even faster shutter speed to avoid motion blur — unless, that is, you use a tripod.

Tripods have come a long way in terms of convenience, and are much lighter, faster to set up, and easier to use than they used to be. Still don't want to lug around a big tripod? Try the Gorillapod, which can wrap around just about anything and provides enough stability for even most DSLR cameras.

Turn up the ISO
ISO is a measure of how sensitive your film is, or if you're using a digital camera, how sensitive the camera's sensor is. A high ISO means that the sensor is picking up much more light, which means that you can use a faster shutter speed and not end up with a black, underexposed picture. So the easiest way to compensate for low-light situations is to change to a higher ISO setting on your camera. Be aware, though, that the higher the ISO, the more digital "noise" you'll have, which means that the resulting photograph will be grainier and not as sharp when you enlarge it.

 

 

Photography Tips: What is ISO?

How film speed affects your photographs, even if you have a digital camera

                                                       If you've been dabbling in photography for a while, you've probably heard of ISO. In the context of photography, an ISO number indicates how "fast" or "slow" a particular type of film (or, more recently, a sensor setting) is — that is to say, how sensitive it is to light. But what is ISO, and how does it affect how you take pictures?

ISO actually refers to the International Organization for Standardization, a group that sets commercial and industrial standards for all sorts of things. In regards to film speed, the ISO set a numbering standard to indicate the sensitivity of different types of film. That way, someone purchasing, say, ISO 200 film (or using a related setting on a digital camera, which we'll get to in a minute) knows how responsive it will be, no matter who manufactured it.

A bit of history
Back in the days of yore, when there was no such thing as digital cameras and everyone popped roll after roll of actual film into their Minolta's, Kodak's, or Canons, a photographer had a lot of choices when it came to film. Black-and-white or color? Slide or print? Perhaps most importantly, what speed?

A film's "speed" refers to its level of sensitivity to light. The lower the number, the less sensitive the film is; the higher the number, the more sensitive. This means that it takes longer to expose ISO 100 film than to expose ISO 800 film.

Why film speed matters

The speed of the film you're using greatly affects the range of shutter speeds you can use to get a properly exposed photo. With a slower film, you'll need a combination of more light and slower shutter speeds, which makes it ideal for things like landscape photography on a sunny day, but terrible for a candlelit dinner or a sporting event. A faster film lets you shoot in lower-light situations or use a much faster shutter speed. Fast film is great for concerts, night photography, or other low-light situations, especially if you don't have a tripod.

So why, you may ask, wouldn't you just use a faster-speed film all the time? The answer is that the faster the film, the grainier the resulting image. This is because the particles in the film that react to light to create the image must be larger in order to absorb more light faster. That's the trade-off with fast film — you'll get a much sharper image in low light or with fast-moving subjects, but you won't be able to enlarge the resulting image as much before you start noticing the film grain. In the side-by-side image below, you can see that when magnified, the digital noise is clearly visible.

Okay, but I'm using a digital camera!

By now you must be wondering how this all relates to digital cameras, since they don't even use film! When you take a picture with a film camera, the light entering the lens strikes the film and exposes it, creating the image. In a digital camera, that light strikes a digital sensor, which actually works much the same way (though of course, in a much more complicated manner). In most basic cameras, the sensor does the work of choosing an appropriate speed (i.e., sensitivity) for you, but in higher-end cameras, you can control it. While they do also work automatically, DSLRs and some compact cameras also have a setting that lets you select a higher or lower ISO than the camera would choose automatically.

This is useful if, for example, you're shooting a concert and the light is very dim, but you can't use the flash. In that situation, you would force the camera to use a much higher ISO (for example, 1600 or higher), which enables you to use a faster shutter speed and reduce blur. As with film, though, you pay for this faster speed with lower image quality; with a digital image, this is called "noise," and it has the consequence of reducing the size to which you can enlarge your photograph without degrading the quality excessively.

Film speed may seem like a complicated thing, but all you really have to remember is that the higher the number, the faster and more sensitive the film, which means the less light it needs. The lower the number, the more light it needs and the higher the resulting image quality.

Open the aperture
Aperture is the term for the actual opening that lets light onto your film or sensor. The aperture sizes are referred to by f-numbers, which actually refer to the ratio of focal length to effective aperture diameter. That's why the numbers are somewhat counterintuitive — the larger the number, the smaller the actual opening. So to allow more light to reach your sensor (thus allowing you to use a faster shutter speed and lower ISO), use a wider aperture with a small number such as f/2 or f/4.

Keep in mind that the size of the aperture also affects your photo's depth of field (the range where things are in focus). The wider the aperture, the smaller the depth of field. This means that if you're photographing a night cityscape, where it's important that elements at various distances all be in focus, you'll need to use a smaller aperture.

Balance the trade-offs
You might have noticed by this point that low-light photography is all about trade-offs. You need to balance the sensitivity of high ISO with the need to reduce digital noise. Balance a wide-open aperture with the resulting small depth of field. Usually, the optimal solution will be some combination of shutter speed, ISO, and aperture settings.

The best way to learn how to balance all these elements is to experiment. Use bracketing to try out the same scene with different settings — try it at 1/30th, 1/60th, and 1/100th of a second, or use f/2, f/2.8, and f/4 apertures, and see what looks best. Make use of whatever light you have. That might mean moving your subject closer to a window or using a table or overhead lamp to provide greater illumination. Keep practicing, and you'll find yourself taking beautiful photographs without ever thinking of using the flash! 

thanks to

by Katherine Gray