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• Its guide number is low, typically 12 meters. This is sufficient for fill flash and short distances.
• It always supports TTL-OTF metering (except for digital cameras).
• It does not support HSS or pre-flash metering (with film cameras).
• It does support ADI when the body supports it.
• It's used as an AF assist light when the camera doesn't have a dedicated AF illuminator.
• It's used as a controller for wireless flash when the body supports it.

Dedicated flashes typically have a higher guide number than built-in flashes, they carry extra batteries, have zooming reflectors and AF illuminators, can tilt and swivel and support additional flash metering modes like pre-flash metering and ADI. See the Flash table to see which Minolta/Sony flash supports which feature.

Wired Flash

The cabling system also allows to attach more than one flash to the camera, and all work in TTL mode.

With modern cameras you use the cable OC-1100/FA-CC1AM to attach the flash to the camera. The OS-1100/FA-CS1AM has an iISO flash foot at one end, the Minolta flash plug at the other end and a coiled 4-wire cable in between. This cable can be extended with the cable EX/FA-EC1AM, which consists of a flash plug, a flash socket and 1 meter of coiled cable. You can use several cables EX/FA-EC1AM to get a really long cable.

The OC-1100/FA-CC1AM cable plugs into a socket at the side of several flash units. Other flash units do not have this socket. For these, you need the OS-1100/FA-CS1AM flash shoe. You mount the flash on the OS-1100/FA-CS1AM like you would mount it on the camera. The OS-1100/FA-CS1AM provides the flash plug socket, a plastic ISO foot (without contacts) and 1/4" threads. The OS-1100/FA-CS1AM is also useful when you like to mount the flash on a bracket or tripod.

See the Flash Table to see which Minolta/Sony flash unit has a built-in socket.

Wireless Flash

Some camera bodies and some flashes support using the flash off-camera without cables. The flash is triggered by the camera body wirelessly. Most bodies use the built-in flash to control the remote flash, or a suitable dedicatated flash mounted on the camera. There is also a separate Wireless Flash Controller. It was primarily intended for the Dynax/Maxxum 9xi which was capable of wireless flash but did not have a built-in flash. The Wireless Flash Controller also works on many later bodies. However, it's discontinued, and some of the latest bodies no longer support it.

With this system, the built-in flash not only triggers the remote flash, but also can stop it. Minolta's wireless flash system therefore is capable of TTL flash metering. The remote flash is not triggered by a simple light pulse like slave flashes. Instead, the body uses a series of coded pulses to control the remote flash. These coded pulses are emitted by the built-in flash. They are weak in intensity, but depending on the lighting situation they may be visible in the picture. To avoid this the Wireless Flash Controller can be used (if supported by the body).

With wireless flash you can also trigger multiple remote flashes. All are started and stopped by the body, so the system still works in TTL mode.

Minolta's wireless flash system uses four channels, and a flash unit can listen on one of the four channels. The camera controls one channel, and all flashes assigned to that one channel are triggered. The body learns the channel by having the flash mounted on the body when switching to wireless flash. This allows to have more than one set of flashes in the same area, each controlled by a different camera. Some flashes support only two of the four channels.

There are three generations of the wireless flash protocol. The characteristics are:

Generation 1: Analog wireless flash

• shutter speed limited to 1/60 or 1/45 (depending on camera)
• allows to balance the built-in flash and the remote flash with a 1:2 ratio, ie. the built-in flash contributes 1/3 of the light and the remote flash contributes 2/3 of the light
• supported by many film cameras, flashes and by Wireless Flash Controller

Generation 2: Wireless HSS and digital

• camera can use shutter speeds between 1/60 and x-sync
• camera can use shutter speeds shorter than x-sync (Wireless HSS)
• supported by DSLRs
• supported by some film cameras (used when shutter speed is shorter than 1/60)
• requires Minolta D flash or Sony flash
• no ratio flash with digital
• not supported by Wireless Flash Controller

Generation 3: Digital ratio flash

• ratio flash with DSLRs
• supported by Sony α700, α850 and α900
• requires Sony HVL-F58AM as controller on camera
• up to 3 flash groups when using only HVL-F42AM and HVL-F58AM as remote flashes
• up to 2 flash groups when using mix of Minolta D flashes and Sony flashes as remote flashes

The following table gives an overview of different wireless setups and the devices involved:

Flash Metering Patterns | Flash Features

© 2010 Michael Hohner; This page was last changed on 2010-06-11