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Revision as of 12:21, 29 August 2011 by Chris (Talk | contribs) (PowerTracking with an AC3 ZoneController)

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PowerTracking allows you to adjust your remote studio flash's output power via the camera's FEC, ISO, and aperture controls. PowerTracking happens automatically when you have a MiniTT1 or FlexTT5 on a Canon or Nikon camera and you are controlling a compatible studio flash connected to a supported PocketWizard radio.

Center Point

The center point for PowerTracking is 3 stops down from your flash's maximum output power. All PowerTracking adjustments are based on this center point. For example, if your flash's maximum output power is 6.5, then the center point is 3.5.

PowerTracking with your camera's controls

If there is no AC3 ZoneController on your transmitter, flash output power on your remote studio flash will track up and down with FEC changes on your camera. Zero (0) on your camera's FEC control is the center point and equals 3 stops down from your flash's maximum output setting. Adjust FEC to raise or lower your flash power.

With Nikon radios and no AC3 ZoneController, only the camera's FEC control will adjust the flash power output level.

With Canon radios and no AC3 ZoneController, the camera's ISO and FEC controls will adjust flash power output level. The ISO used in your first picture after turning the radios on will be used as the center point for PowerTracking.

In the PocketWizard Utility for your transmitting ControlTL radio, this is called Full Manual and is the default operation for PowerTracking when no AC3 ZoneController is in use. See below for settings in the PocketWizard Utility that allow you to customize PowerTracking to also use your camera's aperture controls for Canon and Nikon, or ISO controls for Nikon.

PowerTracking with an AC3 ZoneController

When using an AC3 in A (Auto Mode), flash output power on your remote flash will automatically track up and down with aperture, ISO, and FEC changes on your camera as well as the Power Dial on the AC3. For example: If you narrow your aperture by 1 stop, flash power will increase by 1 stop to keep the exposure the same.

Zero (0) on the AC3 Power Dial is centered on the aperture and ISO used for your first picture. For example, if your first picture is at ISO 200 and F:8, those values will be used as the center point for PowerTracking, which is 3 stops down from your flash's maximum output power.

Follow these steps to set the aperture and ISO values that will be used as the center point:

  • Turn on your camera and MiniTT1 or FlexTT5, but wait to press your shutter button or take any pictures.
  • Set the aperture and ISO you wish to use at the center point. Set the shutter speed as desired. However, changes to shutter speed will not affect PowerTracking.
  • Press the shutter button to take a picture. The center point is now set.
  • Adjust your camera's ISO, aperture, or FEC to control flash output from the camera automatically via PowerTracking.

To change the values sued for the center point, turn off your transmitter then turn it back on and follow these steps again.

Set the AC3 zone to Manual Mode to turn off PowerTracking.

Center on ISO and Aperture with First Shot is the default operation.

IMPORTANT NOTE: Shooting in Shutter Priority/Tv, Program, Full Auto, shooting quickly, or making rapid exposure changes is not recommended. The flash values may change rapidly and your remote flash may not be able to keep up. Honor your flash's ready wait time or "dump" as necessary.

Flash Exposure Compensation (FEC) can be set in many places and all values are added together.

FEC can be set:

  • On the Power Dials of the AC3 ZoneController
  • On the camera for all zones except AC3 Manual zones
  • For transmitting radios, the PocketWizard Utility can adjust the PowerTracking center point for ISO and aperture which affects all zones
  • For the PowerST4 and AC9 AlienBees Adapter, the PocketWizard Utility can adjust FEC for the connected flash on the Exposure Tab

If the combined FEC settings are more or less than your flash's capabilities, then the flash will operate at maximum or minimum output accordingly.

Camera FEC Range

The center point for PowerTracking is 3 stops down from your flash’s maximum, so normally +3 on your camera’s FEC would equal flash maximum power. If your camera has a maximum FEC of +2 stops, and you want that setting to equal your flash’s maximum output, set Flash Exposure Compensation in your PowerST4 to +1.0. When you have made this setting, Zero (0) on your camera’s FEC will now be 2 stops down from flash max instead of 3. If your camera’s highest FEC is +1, set this control to +2.0. You can use this control to align your camera’s lowest FEC setting with your flash’s minimum power similarly.