# Custom Variables 7 and 8 ### **Wireless Flash Wake and Flash Fire (C Var 7 & C Var 8)** **C Var 7 and 8** provide advanced control for managing external flashes, particularly in situations where the **camera cannot wake or trigger flashes automatically**. This feature is especially useful with **Sony cameras**, which do not send a wake signal to flashes before triggering them. While flashes such as the **Camtraptions F1** and **Z2** do not require a wake signal, the **Camtraptions Z Pro** achieves much longer standby times by entering a low-power sleep mode. As a result, it must be **woken** before it can be triggered. In such cases, the **sensor** can take over flash control independently: - **C Var 7 = 1:** The sensor sends a **0.2 s Flash Wake signal** immediately before the **first** camera trigger signal in any stills sequence. This wakes compatible flashes (such as the Z Pro) so that they are ready when the **camera** sends its normal shoot signal. - **C Var 7 = 2:** The sensor sends both a **Flash Wake signal** before the **first** camera trigger signal **and** a **Flash Fire signal** after **every** camera trigger signal. In this configuration, the **camera does not need to send any flash trigger signal**—the sensor handles all flash timing directly. The **wireless channel** used for these **flash signals** is defined by **C Var 8**, which can be set between **1 and 15**. This should be set to a **different channel** than the [main camera trigger channel](https://docs.camtraptions.com/books/pir-v4-manual/page/wireless-channel "Wireless Channel"). The **C Var 7 = 2** configuration is particularly effective for **night-time photography**, where **long shutter speeds** allow the flash to fire during the exposure window. As long as the **shutter speed is longer than the Full-Press duration**, the flash will fire within the open exposure, even when the camera itself is not controlling the flash. The Full-press duration can be customised using C Var 3 so that the flash fires as quickly as possible after the camera shutter opens. This setup provides a **reliable and flexible method** to trigger flashes entirely via the sensor, simplifying configurations where cameras have limited flash-control capabilities or when using **off-camera flash systems** in low-light environments.