Sony A700 Flash

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Sony A700 Flash

The Sony A700 features a built-in, swing-up flash, which operates in either Auto, Fill-Flash, Rear Flash Sync, or Wireless modes. (I call it a swing-up flash because it doesn't pop up automatically when needed, and also doesn't manually pop up at the press of a button under spring pressure, which can be more convenient when you're in a hurry.) To release the flash from its compartment, pull on the two small grips on either side and toward the front of the housing to lift up the flash head. Close it again by pushing the flash head back down.

The Flash mode is changed from the Quick Navi screen (shown at right), or via the Record 2 menu. In Auto flash mode (available only in the camera's Auto or Scene Selection modes), the camera automatically determines when to fire the flash, based on the existing lighting. In Fill-Flash mode, the flash fires with every exposure, regardless of lighting conditions. The Rear Flash Sync mode fires the flash at the end of the shutter time, rather than the beginning. If you have moving objects in a relatively brightly lit environment, this will produce a sharp image of your subject, with a "motion trail" following behind it when shooting at slower shutter speeds. The flash is off when it's closed. The Wireless mode lets the A700 work with compatible remote flash units with wireless capability, such as the Sony HVL-F56AM, HVL-F42AM or HVL-F36AM. Four separate control channels are available for wireless operation, to allow multiple photographers to work wirelessly in the same area without interfering with each other. You can only control the power to a single flash or group of flash units though: It's not possible to separately control the exposure for two or more groups of external flash units, as it is with the Canon (two groups of external units plus the camera's own flash) or Nikon (three groups plus the camera's flash) wireless systems.

A Red-Eye Reduction option is available through the Custom 3 menu. When Red-Eye reduction is enabled, the camera will fire a few low-power flash pulses before it actually snaps the picture, to make the pupils of your subjects' eyes contract.

In Program AE, Full Auto, and Aperture Priority exposure modes, pressing and holding the AE Lock / Slow Sync button (holding it down while you press the shutter button) activates a Slow-Sync mode setting, which uses a slower shutter speed to balance the flash exposure with the ambient lighting. The exposure is based on the ambient light, and the flash power is based on the aperture setting. Results with indoor and outdoor shots that include light fixtures can be dramatic and pleasing.

The A700 offers two methods of flash metering. Its default mode is called ADI, which stands for Advanced Distance Integration. In this mode, it bases its flash exposure on the lens aperture and distance feedback from the autofocus system, as well as on the light reflected back from a pre-flash. By determining how far away the target subject is, the camera knows how much flash power is required to illuminate it, and is less likely to be fooled by subjects that are unusually light or dark overall, or by light subjects against a darker background. Alternatively, the Pre-Flash TTL (through the lens) method bases the exposure determination solely on a low-power metering flash before the main exposure. Used in conjunction with the spot autofocus option, the ADI flash metering should be more accurate with small subjects against a different colored background than the pre-flash method. A manual flash mode is also provided, offering 1/1 (full power), 1/2, 1/4, 1/8 and 1/16 power settings.

The A700's built-in flash has a Guide Number (GN) of 12 meters or 39 feet at ISO 100. Maximum sync speed is 1/200s with Super SteadyShot enabled and 1/250s with stabilization off. High Speed Sync (HSS) shooting with shutter speeds up to 1/8000s is available with Sony HVL-F56AM and HVL-F36AM external flash units.

The A700 also has a top-mounted hot shoe for attaching an external flash unit. The shoe design and contact arrangement are set up for Sony's own dedicated flash units, but I imagine that compatible models are available from the major third-party flash manufacturers (Metz, Sigma, Sunpak, et. al.).

There is also an external flash sync terminal (the so-called "PC" style connector) for third-party flash units, located under a rubber cover on the left side of the camera body. A flash sync voltage of up to 400V is supported.

Flash Test Results

Coverage and Range
Uneven coverage at wide angle, but fairly powerful flash.


16mm	105mm

Normal Flash, +0.7 EV	Slow-Sync Flash, +1.0 EV

Coverage.

Flash coverage was quite uneven at the maximum wide angle lens setting, but this is not really unexpected, especially considering that 16mm is wider than most kit lenses. Coverage was very uniform at telephoto, with the lens itself contributing to some minor corner shading. In the Indoor test, the A700's flash underexposed our subject somewhat at its default setting, requiring a +0.7 EV exposure compensation adjustment (though this appears just a tad bright, +0.5 EV would probably have been better, were it available). The camera's Slow-Sync flash mode produced a more balanced exposure at +1.0 EV, though with a bit more of an orange cast from the background incandescent lighting. Most cameras we test require a +1.0 EV flash exposure adjustment on this shot, so the A700's performance here is pretty good.

Flash Range: Wide Angle
6 ft	7 ft	8 ft	9 ft	10 ft	11 ft
1/60 sec f3.5 ISO 100	1/60 sec f3.5 ISO 100	1/60 sec f3.5 ISO 100	1/60 sec f3.5 ISO 100	1/60 sec f3.5 ISO 100	1/60 sec f3.5 ISO 100
12 ft	13 ft	14 ft	15 ft	16 ft
1/60 sec f3.5 ISO 100	1/60 sec f3.5 ISO 100	1/60 sec f3.5 ISO 100	1/60 sec f3.5 ISO 100	1/60 sec f3.5 ISO 100

Flash Range: Telephoto
6 ft	7 ft	8 ft	9 ft	10 ft	11 ft
1/125 sec f5.6 ISO 100	1/125 sec f5.6 ISO 100	1/125 sec f5.6 ISO 100	1/125 sec f5.6 ISO 100	1/125 sec f5.6 ISO 100	1/125 sec f5.6 ISO 100
12 ft	13 ft	14 ft	15 ft	16 ft
1/125 sec f5.6 ISO 100	1/125 sec f5.6 ISO 100	1/125 sec f5.6 ISO 100	1/125 sec f5.6 ISO 100	1/125 sec f5.6 ISO 100

ISO 100 Range. At ISO 100, images with the 16-105mm kit lens at full wide angle were bright all the way out to the maximum distance we test at, which is 16 feet. At full telephoto, images were bright out to about 10 feet. As can be seen from the wide angle shots though, the longer-than-average kit lens blocks the flash from illuminating part of the frame at 16mm. An external flash can be used to avoid this.

Manufacturer-Specified Flash Range
100mm, f/4.5
8.75 feet ISO 100

Manufacturer Specified Flash Test. As mentioned previously, the Sony A700's built-in flash has a Guide Number of 12m or 39 feet at ISO 100. This works out to 8.75 feet (2.67 m) with an aperture of f/4.5. In the shot above, the A700 seems to perform exactly as Sony's GN rating says it will, producing a good exposure, at the rated distance with its ISO set to 100.

Note: Our standard test method for flash range uses a fixed setting of ISO 100, to provide a fair basis of comparison between cameras. We've now also begun shooting one or two shots using the manufacturer-specified camera settings, at the range the company claims for the camera, to assess the validity of the specific claims.