Measuring Range Extension
Extremely powerful flash and very bright continuous light can be measured by using the special diffuser (+5
stops). Change-over is automatic by the diffuser itself.
Range data: Flash Continuous light (at ISO 100/21°)
Normal diffuser f/1 - 16 EV -2 to +18
Special diffuser f/5.6 - 90 EV +3 to +23
(+ 5 stops)
The special diffuser for measuring range extension is identified by "+5".
Incident Light Measurement- Reflected Light Measurement
With regard to its measuring possibilities and operation, LUNA-STAR F was conceived for professional use.
Due to its swivel sensor (swivel head), the meter is easily adapted to universal service.
Incident light measurement leads to particularly precise exposures. With incident light measurement the
LUNA-STAR F with adjusted diffuser is pointed from the subject towards the camera to measure the incident
light to guarantee a precise exposure in conformity with the correct tonal values of the subject. This is
particularly important with inherently bright or dark subjects. Even in difficult exposure situations, for instance
with contrasty subjects, incident light measurement with the diffuser results in far more accurate exposures to
satisfy the most discerning professional requirements. Incident light measurement is also imperative with
inaccessible subjects. For this purpose it is necessary to select a point that has the same lighting level as the
subject. And then a meter reading is taken with the meter pointed at the same angle towards the camera as it
would babe been from the subject.
This very convenient method of light metering at a point with the same lighting level is highly recommendable
for outdoor shots. The measurement is performed with a complete "about turn" in front of the camera so that the
reading is taken with the meter pointing towards the camera, i.e. opposite the actual picture shooting direction.
Incident light measurement, i.e. with diffuser, also gives a precise reading of the brightness contrast range of the
lighting.
Both kinds of lighting - flash and continuous light- are measured with great accuracy by the incident light
method with diffuser.
Parallel to this the LUNA-STAR F also offers the reflected light measuring method. In this mode the diffuser
has to be removed, and the meter is pointed from the camera towards the subject. The meter now only measures
the light reflected by the subject. Consequently, the reading always depends upon the inherent brightness of the
subject! This means that inherently brighter subjects are not precisely measured and therefore rendered darker.4www. but kus.org
This mode is also used to measure the subject contrast which is displayed by the LUNA-STAR F on its analog
scale.
If readings are to be taken exclusively by the reflected light measuring method, then it is advantageous for the
professional to use a gray card (18% remission capacity) in this mode.
