Flash Exposure Compensation

Trick Photography And Special Effects

Trick Photography and Special Effects

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It's important to keep in mind how the Alpha cameras' exposure compensation system (discussed in Chapter 4) works when you're using electronic flash. To activate exposure compensation for both flash and continuous light sources, choose Flash compens. from the Recording 1 menu. The Flash compens. screen appears (see Figure 7.11), with its plus/minus scale. Use the left/right controller keys to add or subtract exposure. Pressing the right button adds exposure to an image; pressing the left button subtracts exposure. This function is not available when using Auto or Scene exposure modes, nor when you have used the Flash Off option from the Flash menu. Flash exposure compensation affects only the flash, and not continuous light sources, when chosen from the Recording menu. If the camera is set to P, S, A, or M modes, you'll see both flash and continuous lighting compensation represented by separate arrows along the exposure scale. Continuous lighting compensation can be set separately by pressing the Exposure button while rotating the control dial counterclockwise to reduce exposure, and clockwise to increase exposure.

Adjust flash exposure using this screen.

Flash compens.

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Adjust *

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Adjust flash exposure using this screen.

Using the External Electronic Flash

Sony currently offers several accessory electronic flash units for the Sony Alpha cameras. They can be mounted to the flash accessory shoe, or used off-camera with a dedicated cord that plugs into the flash shoe to maintain full communications with the camera for all special features. The beefier units range from the HVL-F58AM (see Figure 7.12), which can correctly expose subjects up to 17 feet away at f/11 and ISO 100, to the (discontinued) HVL-F36AM, which is good out to 11 feet at f/11 and ISO 100. (You'll get greater ranges at even higher ISO settings, of course.) A very inexpensive and useful unit, the $129 HVL-F20AM, was introduced at the same time as this Alpha series. There is also an electronic flash unit, the HVL-RLAM Alpha Ring Light, specifically for specialized close-up flash photography.

HVL-F58AM Flash Unit

This $499 flagship of the Sony accessory flash line is the most powerful unit the company offers, with an ISO 100 guide number of 58/190 (meters/feet). Guide numbers are a standard way of specifying the power of a flash in manual, non-autoexposure mode. Divide the guide number by the distance to determine the correct f/stop. With a GN of 190, you would use f/19 at 10 feet (190 divided by 10), or f/8.5 at 20 feet.

The Sony HVL-F58AM is a top-of-the-line external flash unit for the Alpha.

This flash automatically adjusts for focal length settings from 24mm to 105mm, and a built-in slide-out diffuser panel boosts wide-angle coverage to 16mm. You can zoom coverage manually, if you like. There's also a slide-out "white card" that reflects some light forward even when bouncing the flash off the ceiling, to fill in shadows or add a catch light in the eyes of your portrait subjects.

Bouncing is particularly convenient and effective, thanks to what Sony calls a "quick shift bounce" system. This configuration is particularly effective when shooting vertical pictures. With most other on-camera external flash units, as soon as you turn the camera vertically, the flash is oriented vertically, too, whether you're using direct flash or bouncing off the ceiling (or, wall, when the camera is rotated). The HVL-58AM's clever pivoting system allows re-orienting the flash when the camera is in the vertical position, so flash coverage is still horizontal, and can be tilted up or down for ceiling bounce.

The 15.6 ounce unit uses convenient AA batteries in a four-pack, but can also be connected to the FA-EB1AM external battery adapter (you just blew another $250), which has room for 6 AA batteries for increased capacity and faster recycling. The flash automatically communicates white balance information to your camera, allowing the Alpha to adjust WB to match the flash output.

You can even simulate a modeling light effect. A test button on the back of the flash unit can be rotated for flash mode (one test flash, with no modeling light); three low-power flashes at a rate of two flashes per second, as a rough guide; and a more useful (but more power-consuming) mode that flashes for 40 flashes per second for 4 seconds (160 continuous mini-bursts in all). This switch also has a HOLD position that locks all flash operations except for the LCD data display on the flash, and the test button. Use this when you want to take a few pictures without flash, but don't want to turn off your flash or change its settings.

The HVL-F58AM can function as a main flash, or be triggered wirelessly by another compatible flash unit. The pre-flash from the second "main" flash is used to trigger the remote, wireless flash unit that has been removed or disconnected from the camera. When using flash wirelessly, Sony recommends rotating the unit so that the flashtube is pointed where you want the light to go, but the front (light sensor) of the flash is directed at the flash mounted on the camera. In wireless mode, you can control up to three groups of flashes, and specify the output levels for each group, giving you an easy way to control the lighting ratios of multiple flash units.

Those who are frustrated by an inability to use a shutter speed faster than 1/160th second will love the High Speed Sync (HSS) mode offered by this unit, the HVL-F42AM, and the discontinued HVL-F36AM flash. When activated, you can take flash pictures at any shutter speed from 1/500th to 1/4,000th second! For example, if you want to use a high shutter speed and a very wide aperture to apply selective focus to a subject, HSS is one way to avoid overexposure when using flash. The mode button on the back of the flash is used to choose either TTL or Manual flash exposure. Once the flash mode is chosen, then use the Select button and flash plus/minus keys to activate HSS mode. HSS appears on the data panel of the flash, and an indicator appears on the camera's LCD monitor. (Note: HSS is not available when using the 2-second self-timer or rear-sync mode.)

Keep in mind that because less than the full duration of the flash is being used to expose each portion of the image as it is exposed by the slit passing in front of the sensor, the effective flash range of this "reduced" output is smaller. In addition, HSS cannot be used when using multiple flash or left/right/up bounce flash. (If you're pointing the flash downwards, say, at a close-up subject, HSS can be used.)

Another feature I like is the HVL-F58AM's multiple flash feature, which allows you to create interesting stroboscopic effects with several images of the same subject presented in the same frame, as you can see in Figure 7.13. If you want to shoot subjects at distances of more than a few feet, however, you'll need to crank up the ISO setting of your Alpha, as the output of each strobe burst is significantly less than when using the flash for single shots.

Sony Hvl F58am Strobo

Stroboscopic lighting allows taking several pictures in one frame.

HVL-F42AM Flash Unit

This less pricey ($299) electronic flash shares many of the advanced features of the HVL-F42AM, but has a lower guide number of42/138 (meters/feet). (By now, you've figured out that the number in Sony's electronic flash units represent the GN in meters, so the power rating of the HVL-F36AM, described next, will not come as a surprise to you.)

The shared features include high-speed sync, automatic white balance adjustment, and automatic zoom with the same coverage from 24-105mm (16mm with the slide-out

Stroboscopic lighting allows taking several pictures in one frame.

diffuser). This unit also can be used in wireless mode to operate other Sony strobes using a pre-flash signal. Bounce flash swiveling is still versatile, with adjustable angles of 90 degrees up, 90 degrees left, and 180 degrees right, so you can reflect your flash off ceilings, walls, or persons wearing large items of clothing in light colors. The HVL-F42AM is a tad lighter than its bigger sibling, at 12 ounces.

HVL-F36AM Flash Unit

Although discontinued, you can easily find this versatile flash available online or in used condition. The guide number for this lower cost ($199) Sony flash unit is (surprise!) 36/118 (meters/feet). Although (relatively) tiny at 9 ounces, you still get some big-flash features, such as wireless operation, auto zoom, and high-speed sync capabilities. Bounce flash flexibility is reduced a little, with no swiveling from side to side and only a vertical adjustment of up to 90 degrees available. Like its four siblings, this one uses four AA batteries.

HVL-F20AM Flash Unit

This is the least expensive Sony flash (see Figure 7.14), designed to appeal to the budget conscious, especially those who need just a bit of a boost for fill flash, or want a small unit (just 3.2 ounces) on their camera. It has a guide number of 20/66 (meters/feet) at

Figure 7.14

The HVL-F20AM flash unit is compact and inexpensive.

Figure 7.14

The HVL-F20AM flash unit is compact and inexpensive.

ISO 100, and features simplified operation. For example, there's a switch on the side of the unit providing Indoor and Outdoor settings (the Indoor setting tilts the flash upwards to provide bounce light; with the Outdoor setting, the flash fires directly at your subject). There are special modes for wide-angle shooting (use the built-in diffuser to spread the flash's coverage to that of a 27mm lens) or choose the Tele position to narrow the flash coverage to that of a 50mm lens for illuminating more distant subjects. While it's handy for fill flash, owners of an Alpha A550 or A500 will probably want a more powerful unit as their main electronic flash.

More Advanced Lighting Techniques

As you advance in your Sony Alpha photography, you'll want to learn more sophisticated lighting techniques, using more than just straight-on flash, or using just a single flash unit. Entire books have been written on lighting techniques. (If you're really into complex lighting setups, you might want to check out my book, David Busch's Quick Snap Guide to Lighting, available from the same folks who brought you this guidebook.) I'm going to provide a quick introduction to some of the techniques you should be considering.

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Digital Camera and Digital Photography

Digital Camera and Digital Photography

Compared to film cameras, digital cameras are easy to use, fun and extremely versatile. Every day there’s more features being designed. Whether you have the cheapest model or a high end model, digital cameras can do an endless number of things. Let’s look at how to get the most out of your digital camera.

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