Evert, George's description above is for measuring the light that is reflected from the kids. For that, if you followed the Sekonic instructions, you would have had to push the dome to one side and replace it with a flat disk accessory (the Lumidisk) and point it
at the kids. Do not be confused - this is the method George is referring to and it is called reflected light metering.
Incorrect and misleading.
Incorrect. The convention is to point the dome at the camera, not at the sun.
Incorrect - unless George can post a link to where Sekonic says exactly that.
But did I wonder about the meaning of "cap" so I looked in the Sekonic 308 manual - no such item is mentioned. Maybe George is talking about the Lumidisk being fitted and used to measure light from
several sources in a
studio - not applicable in the case of your kids sitting outside illuminated only by the sky. Way more complication than you need, Evert.
The purpose of the dome is a) to collect light in an approximately
cardioid 3D pattern and, internally, to diffuse that collected light evenly over the sensor. The gain is set by circuitry internally to give incident light readings either in lux or foot-candles (some models in cd/m^2) - George's 18% does not come into that calculation at all.
A useful one-page link for beginners.
George's English is much better than my
Nederlands !!
Evert, PLEASE put us out of our misery. Did you point the dome at the kids, the camera position or the sky ??