Metz 34 AF-3M operating instructions TTL flash control

Page 10

5. TTL flash control

The mecablitz receives its information exclusively from the connected TTL-controlled camera.

Exposure measurement in TTL mode (TTL = through-the-lens) is completed by the camera’s sensor. This sensor measures the light reaching the film through the camera lens. An electronic control circuit within the camera transmits a stop signal to the flashgun as soon as the film has been exposed by the correct amount of light; the flash is then instantly cut out.

The advantage of the TTL mode is that all factors influencing the exposure of the film (such as fil- ters, change of aperture or variable aperture zooms) are taken into account. You need not worry about adjustment of the light output. The camera’s electronic system automatically defines the requi- red amount of light. You can also utilize various metering facilities (e.g. spot , matrix or centre- weighted overall readings) offered by some came- ras.

The table on page 37 gives the maximum range for the selected aperture. The minimum lighting distance is approx. 15% of the maximum thres- hold range.

If the actual distance is shorter than the minimum lighting distance, then this may result in overexposure.

The speed of films to be exposed under TTL flash control must be between ISO 25/15°* and ISO 1000/31°. Correct expo- sures cannot be guaranteed with other film speeds.

A strip of film must be loaded in the camera if tests are to be conducted in TTL flash mode. The effec- tive flash range can only be checked by the cor- rect-exposure display (o.k.) if the flash is triggered by the camera and not with the manual release on the flashgun!

*With automatic film speed setting (DX): ISO 32/16°

9

Image 10 Metz 34 AF-3M operating instructions TTL flash control
Contents Mecablitz 34 AF-3 M Foreword Dear CustomerContents Disposal of batteries Safety instructionsDo not short-circuit batteries! Danger of Explosion Do not dispose of spent batteries with domestic rubbishPreparing the mecablitz for use Power supplyLoading and exchanging batteries Automatic flashgun switch-off Mounting/Removing the flashgunFeatures this function Setting the mecablitz into operationSwitching the flashgun on and off Automatic flash sync speed control Flashgun instructions to the cameraFlash-ready indication Correct-exposure indication see figDisplays Meaning Viewfinder TTL flash control Normal synchronisation Flash synchronisationSlow-synchronisation Second curtain synchronisation Rear Flash in the individual camera modes Auto program mode with flash P-functionFlash in the A, S and M modes AF red-light beam Autofocus measuring flashOnly the central AF sensor is supported Fill-in flash Flash techniques and flash functionsExposure correction Mounting and removing the attachments Lighting and attachmentsGuiding edge Case gap Switch off the flashgun with the main switch Care and maintenance TroubleshootingTroubleshooting Forming the flash capacitorFlash duration Technical dataColour temperature approx K Synchronization Number of flashes Flash recycling timeLighting distances Sticker can be applied to the back of the flashgun