Figure 6-13: Portrait without and with fill flash.
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Figure 6-13: Portrait without and with fill flash. |
Normally, the camera makes the assumption that the flash will be providing the only source of light. If you are shooting a dance party in a darkened room this is not a bad assumption and the images will come out well-exposed (well… the subjects will be well-exposed, and the backgrounds black.)
But when the majority of the subject’s illumination comes from another source (usually the sun), then the flash gives only a tiny burst of light, just enough to lighten the shadows a little bit (see Figure 6-13). Your camera automatically switches between these two modes when the flash is used. The best time to use it is when your subject is in shade on a bright day. For example, in Figure 6-13, the light was poor and the subject (the face of the fisherman) was in shade, under his hat. It looked fine to me when I was standing there, but because cameras don’t see the same range of light as the human eye, fill-flash was in order.
This does EXACTLY the same thing as Night Portrait mode (Section 6.38.8) – that is, when you take a flash picture at night, instead of the shutter speed defaulting to 1/60th of a second, it will be whatever it would normally be had the flash not been enabled. That way you can “burn in” your ambient light yet still illuminate your subject via the flash.
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Figure 6-14: Selecting “Slow Sync” from the flash menu will “drag the shutter” and give you a long nighttime exposure along with a flash burst. |
The only difference between this and the Night Portrait function is that with the slow sync function, you can change important parameters like ISO, white balance, exposure compensation, etc.
To invoke the Slow Sync function, set up a flash shot as you normally would in P/A/S/M mode and then MENU --> 
3 --> Flash Mode --> Slow Sync (or via the Fn menu).
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Figure 6-15: The Slow-Sync function will help you balance out the light from the flash and allow the background light (dim as it may be) to show up brighter than if your camera were simply in Auto mode. |
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Figure 6-16: Invoking the Rear Sync function. |
Rear Sync is an indispensable tool for certain kinds of action shots where ambient light (with longish shutter speeds) is combined with flash. The classic image is a person running in a marathon, with a “ghost” trail behind them.
When you use a fast shutter speed, flash pictures are easy: The exposure starts, the flash goes off, and the exposure stops. Not too hard. But, what if you kept the shutter open for several seconds and you wanted to use the flash? When should the flash fire – at the beginning of the exposure, or at the end, coinciding with the 2nd or “rear” shutter curtain? Most cameras will only fire the flash at the beginning of the exposure. The Rear-Sync function tells the camera to select the second option: fire the flash near the end of the
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Figure 6-17: Examples of Normal (left) and Rear (right) Flash Sync The idea is that you can control leading or trailing light when you’re using both long shutter speeds (ambient) and flash on a moving subject. Rear sync (right) allows the pedestrian’s trail to show up behind him, whereas with normal settings (left) the trail appears in front of him! Who wants that? For this shot, the shutter speed was set to 1.5 seconds to capture the motion, and the flash still went off to freeze the subject – hence we have both a blur and a “frozen” subject all in the same shot.
Figure 6-18: Wireless Flash will add “Wow!” (or in this case, “Solemnness!”) to your photography like nothing else. |
exposure, at a time when the rear shutter curtain would close. When would you want to do this? See Figure 6-17.
In order to use wireless flash you need to purchase two accessory flashes – one that sits on the camera’s hot shoe, the other placed anywhere. It’s so valuable that I’ve dedicated an entire chapter to it (Chapter 13).
Menu Position Menu --> 
3 --> Flash Comp.
What it Does Allows you to specify whether the camera generates more flash or less flash intensity
Recommended Setting -1
The Flash Compensation function only varies the intensity of the flash when it’s used – it has no effect on the ambient light (for that, you should use the Exposure Compensation function (Section 6.19), which adjusts BOTH the ambient AND flash).
Oddly this feature is greyed out in anything other than P, A, S, or M modes.
Why do I recommend that it be set to -1? Have a look at Figure 6-19
Figure 6-19: Left to its own devices, the A6300 will tend to overexpose a flash picture by one stop. So I set Flash Exposure Compensation to -1 so that an average scene (like this grey card) will photograph as an average scene. |
