I'm renting a Polaris flash meter.
It's the one with the sliding white dome.
I'm confused as to which mode is incident and reflective - with the dome on or dome off?

Inicident is with the dome on; point the meter toward the camera and position it close to the subject. Reflective is with the dome off; point it toward the subject and take care not to block the flash with your body or the meter. In reflected mode, you can take a reading of different parts of the subject by positioning the meter close to the subject or you can position the meter near the camera to take an average reading.

understood
thanks