Pentax 12161, 12195 Using the Trailing Curtain Sync, 209, Sensitivity Built-in Flash Guide Number

209

Using the Trailing Curtain Sync

Trailing Curtain Sync discharges the flash immediately before the shutter closes. When shooting moving objects with a slow shutter speed, Trailing Curtain Sync and Slow-speed Sync produce different effects depending on when the flash is discharged.

For example, when shooting a moving car with Trailing Curtain Sync, trailing light is captured while the shutter is open and the flash captures the car immediately before the shutter is closed. Therefore, the picture will include a sharp, well-lit car with trailing light behind it.

Slow-speed Sync

(Leading Curtain Sync)

Trailing Curtain Sync

Trailing Curtain Sync slows down the shutter speed. Use the Shake Reduction function, or turn off the Shake Reduction function and use a tripod to avoid camera shake.

Distance and Aperture when Using the Built-in Flash

Relationships among the guide number, aperture and distance must be considered when shooting with the flash to obtain a correct exposure. Calculate and adjust the shooting conditions if the flash output is not sufficient.

Sensitivity	Built-in Flash	Sensitivity	Built-in Flash
	Guide Number		Guide Number
ISO 100	Approx. 4.9	ISO 1600	Approx. 20
ISO 200	Approx. 7	ISO 3200	Approx. 28
ISO 400	Approx. 10	ISO 6400	Approx. 40
ISO 800	Approx. 14

10

Using the Flash