Sony Alpha DSLR-A100
Sony A100 Flash
The Sony A100 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 would be more convenient when you're in a hurry.) To release the flash from its compartment, pull on the two silver rails on either side and toward the front of the casing to lift up the flash head. Close it again by pushing the flash head back down. The Flash mode is changed through the Flash setting on the Function dial. In Auto flash mode, 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. The flash is in the Off position when it's closed. The Wireless mode lets the camera work with wireless remote flash units, with four channels available through the settings menu, so different camera/flash setups working in the same area won't interfere with each other. A Red-Eye Reduction option is available through the settings menu.
In Program AE, Full Auto, and Aperture Priority exposure modes, pressing and holding the AE Lock button activates a Slow-Sync mode setting, which balances 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 A100 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. Alternatively, the Pre-Flash TTL (through the lens) method bases the exposure determination solely on a small metering flash before the main exposure. Used in conjunction with the spot autofocus option mentioned earlier, the ADI flash metering should be more accurate with small subjects against a different colored background than the pre-flash method.
The A100 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 (Sunpak et. al.).
There is no external flash sync terminal (the so-called "PC" style connector) for third-party flash units.
Sony A100 Remote, Wireless Flash
Part of the technology Sony inherited from Konica Minolta was a sophisticated wireless remote flash system, whereby a flash unit on the A100 can control several remote flashes. We didn't get to experiment with this in our studio, but did spend some time playing with it on the press tour Sony put on for the A100 rollout. We were impressed with its capability, the ability to control off-camera strobes from your shooting position is a very powerful creative tool. (NOTE though, that the Sony A100 requires a separate on-camera strobe unit to control the remote units: The camera's built-in flash has no remote control abilities.) We were shooting action on a stage in a fairly large room though, and found that the strobes off at the sides of the stage area sometimes had a hard time seeing the command and trigger pulses from our camera-mounted unit. We're not sure whether this is a limitation of the flash system, or whether it was simply a matter of taking more care in setup to give the flash units a clear line-of-sight to each other. (On our "someday" list of articles to write is a comparison of wireless flash systems by Canon, Nikon, and Sony. It would be very interesting to set them up in a controlled environment, and see just how well each triggers under identical conditions.) The shot at right gives some idea of what can be accomplished with off-camera flash, using the Sony wireless strobe system. (Sure beats the standard ghastly on-camera flash angle, doesn't it?)
Sony A100 Flash Test Results
Coverage and Range
A bright flash with good coverage up close, but a fair bit of falloff at maximum wide angle. Our standard shots required about average positive exposure compensation.
|18mm equivalent||70mm equivalent|
|Normal Flash +1.0 EV||Slow-Sync Flash +1.3 EV|
Flash coverage was a bit uneven at the maximum 18mm wide angle lens setting, but much more uniform at telephoto. In the Indoor test, the A100's flash underexposed our subject somewhat at its default setting, requiring a +1.0 EV exposure compensation adjustment (though this appears just a tad bright). The camera's Slow-Sync flash mode produced a more balanced exposure at +1.3 EV, though with a stronger orange cast from the background incandescent lighting. Most cameras we test require a +1.0 EV flash exposure adjustment on this shot, so the A100's performance here is pretty typical.
The A100's flash remained bright, with good coverage throughout the test range. Exposures were also good with the optional wireless flash, which produced a much more balanced exposure. Range with the kit lens was about 11 feet at wide angle, but only 7-8 feet at maximum telephoto.
|Manufacturer-Specified Flash Range|
Our standard test method for flash range uses a fixed setting of ISO 100, to provide a fair basis of comparison between cameras. We also capture two shots using the manufacturer-specified camera settings, at the range the company claims for the camera, to assess the validity of their claims. In the shot above, the Sony A100 seems to perform exactly as the spec sheet says: The flash guide number is listed as 12 meters at ISO 100. With the kit lens at wide angle and maximum aperture of f/3.5, this corresponds to 12/3.5 = 3.42 meters = 11.2 feet.
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Note: For details, test results, and analysis of the many tests done with this camera, please click on the tabs at the beginning of the review or below.