The Promote Control Bulb Ramping / Bulb HDR Assistant Kit helps create high precision bulb Time-Lapse sequences, ensuring accuracy of up to 0.001 EV steps. Now you can create stunning time-lapse sequences of sunsets or other variable light conditions. In addition, this Kit enables Bulb HDR on select cameras (please see compatibility information). Features: Ensures high precision bulb ramping for Time-Lapse sequences in variable light conditions * Enables Bulb HDR on select cameras. * * NOTE 1: This Kit cannot be used without a camera-specific shutter cable. Please also choose a shutter cable that matches your camera model. * NOTE 2: This Kit assumes manual pre-entry of the start exposure for Bulb Ramping and Bulb HDR, and cannot automatically measure ambient light. Please read below for usage instructions. Compatibility This Kit is compatible with Canon EOS cameras (also requires a camera specific shutter cable - see above). Promote Control firmware version 2.30 or higher is also required.