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3.4.4 Important remarks concerning correction values
The DFM 3 is a precision meter calibrated with great accuracy to provide exact exposure data. Should
you still not be satisfied with the results, then you should remember that there are independent variables
that can influence the success of your exposures.
For instance:
•
the true speed of your film can deviate from that on the pack
•
the true shutter speeds and f-stops of your camera can differ slightly form the rated values
•
Deviations can arise when the film is processed.
Also, there must be added purely subjective factors and matters of personal preference in the
assessment of the finished photos. However, you can calibrate your DFM 3 to characteristics of your
camera, your brand of film, your processing methods and to your projector.
We recommend the following procedure:
Take the readings of a few normal subjects with the utmost care by the reflected and incident light
measuring methods, and take five shots of each subject on color reversal film. The first picture should
be exposed with the exposure settings supplied by the DFM 3. The exposure settings for the remaining
shots are then increased and decreased, respectively, by half an f-stop and then a full
f-stop. Make a note of the shooting conditions. These must not change while the five shots are being
taken. Now select from the processed pictures the one you consider to be optimal and compare its
settings with the meter readings.
If you find that you prefer exposures taken with settings that differ from those supplied by the meter,
then these settings can be programmed, as a correction, into your DFM 3. With your correction, the
DFM 3 will give precise readings to produce optimal exposure results.