There is no reason to put your camera away when the sun goes down. Your 50D has some great features that let you work with available light as well as the built-in flash. In this chapter, we will explore ways to push your camera’s technology to the limit in order to capture great photos in difficult lighting situations. We will also explore the use of flash and how best to utilize your built-in flash features to improve your photography. But let’s first look at working with low-level available light.

Let’s begin with the obvious way to keep shooting when the lights get low: raising the ISO (Figure 8.1). By now you know how to change the ISO: just press the ISO button on the top of the camera and turn the Main dial to adjust. In typical shooting situations, you should keep the ISO in the 100–800 range. This will keep your pictures nice and clean by keeping the digital noise to a minimum. But as the available light gets low, you might find yourself working in the higher ranges of the ISO scale, which could lead to more noise in your image.

Figure 8.1. To get a good exposure inside a museum, you will often be forced to raise your ISO. I also balanced the camera on a railing to help steady the shot.

You could use the flash, but that has a limited range (15–20 feet) that might not work for you. Also, you could be in a situation where flash is prohibited, or at least frowned upon, like at a wedding or in a museum.

And what about a tripod in combination with a long shutter speed? That is also an option, and we’ll cover it a little further into the chapter. The problem with using a tripod and a slow shutter speed in low-light photography, though, is that it performs best when subjects aren’t moving. Besides, try to set up a tripod in a museum and see how quickly you grab the attention of the security guards.

So if the only choice to get the shot is to raise the ISO to 800 or higher, make sure that you turn on the High ISO Noise Reduction feature (Figure 8.2). This custom menu function is set to Standard by default, but as you start using higher ISO values you should consider changing it to the Strong setting. (Chapter 7 explains how to set the noise reduction features.)

Figure 8.2. Although this looks like a well-lit shot, it was a handheld shot made possible through the use of a very high ISO, along with the High ISO Noise Reduction feature turned on.

To see the effect of High ISO Noise Reduction, you need to zoom in and take a closer look (Figures 8.3 and 8.4).

Figure 8.3. Here is a close-up of the same flower, so you can get an idea of how things look with High ISO Noise Reduction turned off.

Figure 8.4. Here is the same flower photographed with High ISO Noise Reduction turned to Strong. While it doesn’t get rid of all the noise, it certainly reduces the effect and improves the look of your image.

Raising the noise reduction to the Strong setting slightly increases the processing time for your images, so if you are shooting in the High-speed continuous drive mode you might see a little reduction in the speed of your frames per second.

Is ISO 3200 just not enough for you? Well, in that case, you will need to turn on the ISO Expansion setting. This setting opens up two more stops of ISO, raising the new limit to an incredible 12800. The new settings will not appear in your ISO scale as numbers, but as H1 for 6400 and H2 for 12800.

Setting Up the ISO Expansion Feature

1. Press the Menu button and locate the Custom Function screen.

2. The ISO Expansion setting is located in the C. Fn I:Exposure section. Highlight it and press Set (A).

   

   A

3. Locate the ISO Expansion menu and change the setting from Off to On (B).

   

   B

4. Press the Menu button twice to exit, then press the ISO button and set the H1 or H2 settings with the Main dial.

A word of warning about the expanded ISO settings: although it is great to have these high ISO settings available during low-light shooting, they should always be your last resort. Even with the High ISO Noise Reduction turned on, the amount of visible noise will be extremely high. I can’t think of a situation where I ever need to use the 12800 (H2) setting, but you might find yourself at a nighttime sporting event under the lights, which would require ISOs of 3200 or 6400 to improve your shutter speeds and capture the action (Figure 8.5).

Figure 8.5. The only way to get a fast-enough shutter speed during this night game was to raise the ISO to 6400.

Manual Callout

For a complete table listing of all the programmable custom functions, including the ISO Expansion feature, turn to page 173 in your owner’s manual.

If you purchased your camera with one of the new image stabilization (IS) lenses, you already own a great tool to squeeze two stops of exposure out of your camera when shooting without a tripod. Typically, the average person can handhold their camera down to about 1/60 of a second before blurriness results due to hand shake. As the length of the lens is increased (or zoomed), the ability to handhold at slow shutter speeds (1/60 and slower) and still get sharp images is further reduced.

The Canon IS lenses contain small gyro sensors and servo-actuated optical elements, which correct for camera shake and stabilize the image. The IS function is so good that it is possible to improve your handheld photography by two or three stops, meaning that if you are pretty solid at a shutter speed of 1/60, the IS feature lets you shoot at 1/15, and possibly even 1/8 of a second (Figures 8.6 and 8.7).

Figure 8.6. Both of these images were shot at the same camera settings, one with and one without the IS enabled.

Figure 8.7. Looking at enlargements of the two images, it’s easy to see the difference that image stabilization can make in your low-light photography.

The 50D has a great focusing system, but occasionally the light levels might be too low for the camera to achieve an accurate focus. There are a few things that you can do to overcome this obstacle.

First, you should know that the camera utilizes contrast in the viewfinder to establish a point of focus. This is why your camera will not be able to focus when you point it at a white wall or a cloudless sky. It simply can’t find any contrast in the scene to work with. Knowing this, you might be able to use a single focus point in One Shot mode to find an area of contrast that is of the same distance as your subject. You can then hold that focus by holding down the shutter button halfway and recomposing your image.

Then there are those times when there just isn’t anything there for you to focus on. A perfect example of this would be a fireworks display. If you point your lens to the night sky in any automatic focus (AF) mode, it will just keep searching for—and not finding—a focus point. On these occasions, you can simply turn off the autofocus feature and manually focus the lens (Figure 8.8). Look for the AF/MF switch on the side of the lens and slide it to the MF position.

Figure 8.8. Focusing on the night sky is best done in manual focus mode.

Don’t forget to put it back in AF mode at the end of your shoot.

We have covered some of the techniques for shooting in low light, so let’s go through the process of capturing a night or low-light scene for maximum image quality (Figure 8.9). The first thing to consider is that in order to shoot in low light with a low ISO, you will need to use shutter speeds that are longer than you could possibly handhold (longer than 1/15 of a second). This will require the use of a tripod or stable surface for you to place your camera on. For maximum quality, the ISO should be low—somewhere below 400. The long exposure noise reduction should be turned on to minimize the effects of exposing for longer durations. (To set this up, see Chapter 7.)

Figure 8.9. A fairly long exposure and a tripod were necessary to catch the last glow of twilight over Las Vegas.

Once you have the noise reduction turned on, set your camera to Aperture Priority (Av) mode. This way, you can concentrate on the aperture that you believe is most appropriate and let the camera determine the best shutter speed. If it is too dark for the autofocus to function properly, try manually focusing. Finally, consider using a cable release (see the bonus chapter) to activate the shutter. If you don’t have one, check out the sidebar on using the self-timer. Once you shoot the image, you may notice some lag time before it is displayed on the rear LCD. This is due to the noise reduction process, which can take anywhere from a fraction of a second up to 30 seconds, depending on the length of the exposure.

There are going to be times when you have to turn to your camera’s built-in flash to get the shot. The pop-up flash on the 50D is not extremely powerful, but with the camera’s advanced metering system it does a pretty good job of lighting up the night...or just filling in the shadows.

If you are working in the Creative zone, you will have to turn the flash on for yourself. To do this, just press the pop-up flash button located on the front of the camera (Figure 8.10). Once the flash is up, it is ready to go (Figure 8.11). It’s that simple.

Figure 8.10. A quick press of the pop-up flash button will release the built-in flash up to its ready position.

Figure 8.11. The pop-up flash in its ready position.

Shutter Speeds

The standard flash synchronization speed for your camera is between 1/60 and 1/250 of a second. When you are working with the built-in flash in the Basic zone, the camera will typically use a shutter speed of 1/60 of a second. The exception to this is when you use the Night Portrait mode, which will fire the flash with a slower shutter speed so that some of the ambient light has time to record in the image.

The real key to using the flash to get great pictures is to control the shutter speed. The goal is to balance the light from the flash with the existing light so that everything in the picture has an even illumination. Let’s take a look at the shutter speeds for the modes in the Creative zone.

• Program (P): The shutter speed stays at 1/60 of a second. The only adjustment you can make in this mode is overexposure or underexposure using the Quick Control dial to change the f-stop.

  

• Shutter Priority (Tv): You can adjust the shutter speed to as fast as 1/250 of a second all the way down to 30 seconds. The lens aperture will adjust accordingly, but typically at long exposures the lens will be set to its largest aperture.

  

• Aperture Priority (Av): This mode has three custom settings for adjusting the shutter speed when using the flash, depending on your needs. The whole point of this setting is to allow you to use the aperture of your choice while still getting good flash exposures.

  

The default value is Auto, which adjusts from 1/250 all the way down to 30 seconds, depending on the available light. As the aperture gets smaller, the shutter speeds will get longer. There are also two speed-limiting settings to choose from. The first is “1/60 to 1/250 sec. auto.” This limits the shutter speed to a maximum duration of 1/60 of a second. If you have the aperture open to an f-stop that has a very small opening for a proper exposure, the shutter speed indicator will flash, letting you know that you are risking underexposure. For all other exposures, the camera will moderate the shutter speed to a selection that is within the 1/60–1/250 range. The other setting is “1/250 sec. (fixed).” This setting maintains a shutter speed of 1/250 of a second no matter what the f-stop is set to.

Setting the Sync Speed When Using Flash in Av Mode

1. Press the Menu button and use the Main dial to get to the Custom Function menu tab.

2. Select C. Fn I: Exposure using the Quick Control dial and press the Set button (A).

   

   A

3. Rotate the Quick Control dial to get to the seventh function, Flash sync. speed in Av mode, and press the Set button.

4. Select the Av sync speed that you desire using the Quick Control dial and press Set once more (B).

   

   B

• Manual (M): Manual mode works the same as Tv mode, with a range of 1/250 down to 30 seconds. The difference, of course, is that you must manually set the f-stop.

  

• A-DEP: The shutter speed for this mode ranges from 1/60 to 1/250 of a second, and will be set automatically depending on the available light.

  

Generally speaking, I like to have my Mode dial set to the Shutter Priority (Tv) mode when shooting pictures with flash. This enables me to balance out the existing light with the flash, which sometimes requires longer shutter speeds.

Flash Range

Because the pop-up flash is fairly small, it does not have enough power to illuminate a large space (Figure 8.12). The effective distance varies depending on the ISO setting. At ISO 100, the range is about 12 feet. This range can be extended to as far as 138 feet when the camera is set to an ISO of 12800. For the best image quality, your ISO setting should not go above 800. Anything higher will begin to introduce excessive noise into your photos.

Figure 8.12. The pop-up flash was used to fill in shadows on the elephant while the long exposure time allowed the ambient light to illuminate the rest of the scene.

The E-TTL system will usually do an excellent job of balancing the flash and ambient light for your exposure, but it does have the limitation of not knowing what effect you want in your image. You may want more or less flash in a particular shot. You can achieve this by using the Flash Exposure Compensation feature.

Just as with exposure compensation, flash compensation allows you to dial in a change in the flash output in increments of 1/3 of a stop. You will probably use this most often to tone down the effects of your flash, especially when you are using the flash as a subtle fill light (Figures 8.13–8.15).

Figure 8.13. This is a standard image made in a museum with no flash. The exposure is not bad, but the detail in the shadow areas of the skull are too dark.

Figure 8.14. Turning on the flash without any compensation completely overpowers the scene and creates harsh shadows.

Figure 8.15. Combining a slow shutter speed for the ambient light and subtracting one stop of compensation on the flash resulted in a greatly improved image.

Using the Flash Exposure Compensation Feature to Change the Flash Output

1. Press the ISO/Flash Compensation button to get to the compensation setup mode.

2. Look at the top LCD screen (or in the view-finder) and spin the Quick Control dial to change the output of the flash. Turning clockwise towards the plus-sign side of the scale adds exposure (more flash power), and turning counterclockwise toward the minus sign will reduce exposure (less flash power). Note that turning the Main dial will result in a change of ISO, so be sure to use the Quick Control dial.

3. Press the shutter button halfway to return to shooting mode, and then take the picture.

4. Review your image to see if more or less flash compensation is required, and repeat these steps as necessary.

The Flash Exposure Compensation feature does not reset itself when the camera is turned off, so whatever compensation you have set will remain in effect until you change it (Figure 8.16). Your only clue to knowing that the flash output is changed will be the presence of the Flash Exposure Compensation symbol in the viewfinder. It will disappear when there is zero compensation set.

Figure 8.16. The Flash Exposure Compensation scale will alert you to the amount of compensation you have dialed in.

We’ve all seen the result of using on-camera flashes when shooting people: the dreaded red-eye! This demonic effect is the result of the light from the flash entering the pupil and then reflecting back as an eerie red glow. The closer the flash is to the lens, the greater the chance that you will get red-eye. This is especially true when it is dark and the subject’s eyes are dilated. There are two ways to combat this problem. The first is to get the flash away from the lens. That’s not really an option, though, if you are using the pop-up flash. Therefore, you will need to turn to the Red-Eye Reduction feature.

This is a simple feature that shines a light from the camera at the subject, causing their pupils to shrink, thus eliminating or reducing the effects of red-eye (Figure 8.17).

Figure 8.17. Notice that the pupils on the image without red-eye are smaller as a result.

The feature is set to Off by default and needs to be turned on in the shooting menu.

There are two flash synchronization modes in the 50D. There’s first curtain and second curtain. You may be asking, “What in the world does synchronization do, and what are these ‘curtains’?” Good question.

When your camera fires, there are two curtains that open and close to make up the shutter. The first curtain moves out of the way, exposing the camera sensor to the light. At the end of the exposure, the second curtain moves in front of the sensor, ending that picture cycle. In flash photography, timing is extremely important because the flash fires in milliseconds and the shutter is usually opening in tenths or hundredths of a second. To make sure these two functions happen in order, the camera usually fires the flash just as the first curtain moves out of the way (see the sidebar earlier in the chapter about flash sync).

In 2nd Curtain Sync mode, the flash will not fire until just before the second shutter curtain ends the exposure. So, why have this mode at all? Well, there might be times when you want to have a longer exposure to balance out the light from the background to go with the subject needing the flash. Imagine taking a photograph of a friend standing in Times Square at night with all the traffic moving about and the bright lights of the streets overhead. If the flash fires at the beginning of the exposure, and then the objects around the subject move, those objects will often blur the subject a bit. If the camera is set to 2nd Curtain Sync, though, all of the movement is recorded by the existing light first, and then the subject is “frozen” by the flash at the end by the exposure.

There is no right or wrong to it. It’s just a decision on what type of effect it is that you would like to create. Many times, 2nd Curtain Sync is used for artistic purposes or to record movement in the scene without it overlapping the flash-exposed subject (Figure 8.18). To make sure that the main subject is always getting the final pop of the flash, I leave my camera set to 2nd Camera Sync.

Figure 8.18. Using 2nd Curtain Sync is most evident during long flash exposures.

Figure 8.19 shows an example of a fairly long exposure to record the light trails from the passing traffic, with a burst of flash at the end that gives a ghostly appearance to the subject.

Figure 8.19. This effect is possible because the flash fired at the end of the exposure using 2nd Curtain Sync.

Using 1st Curtain Sync mode will give a similar effect, but all of the light trails will be in front of the vehicles, not behind them, because the flash fired at the beginning of the sequence (Figure 8.20).

Figure 8.20. 1st Curtain Sync is the default setting for flash photography and can be used for longer exposures as long as the subject remains still.

If you do intend to use a long exposure with first curtain synchronization, you need to have your subject remain fairly still so that any movement that occurs after the flash goes off will be minimized in the image.

If you find yourself in a situation where you want to use your flash to shoot through a window or display case, try placing your lens right against the glass so that the reflection of the flash won’t be visible in your image (Figures 8.21 and 8.22). This is extremely useful in museums and aquariums.

Figure 8.21. The bright spot at the top of the frame is a result of the flash reflecting off the display case.

Figure 8.22. To eliminate the reflection, place the lens against the glass or as close to it as possible. This might also require zooming the lens out a little.

We have discussed several ways to get control over the built-in pop-up flash on the 50D. The reality is that, as flashes go, it will only render fairly average results. For people photography, it is probably one of the most unflattering light sources that you could ever use. This isn’t because the flash isn’t good—it’s actually very sophisticated for its size. The problem is that light should come from any direction besides the camera to best flatter a human subject. When the light emanates from directly above the lens, it gives the effect of becoming a photocopier. Imagine putting your face down on a scanner: the result would be a flatly lit, featureless photo.

To really make your flash photography come alive with possibilities, you should consider buying an external flash such as the Canon Speedlite 430EX II. The 430EX has a swiveling flash head, more power, and communicates with the camera and the E-TTL system to deliver balanced flash exposures. For more information about the Canon Speedlite system, be sure to check out the bonus chapter.

Now that we have looked at the possibilities of shooting after dark, it’s time to put it all to the test. These assignments cover the full range of shooting possibilities, both with flash and without. Let’s get started.