Olympus 400Z Issues (C-900 Zoom in Europe)
Sensitivity
Olympus 400z seem to systematically require +1 EV exposure compensation in order to provide normally exposed photos (full histogram). This seems to translate to the fact that the ISO (or ASA) rating of the camera actually is only 30/60 not the specified 60/120.
Hue Shift / Gamma Space
400z outputs highly saturated colors with large hue-shifts as can be seen from the below test shots of Kodak Q-60 calibration target.The hue-shift is due to the fact that the monitor compensation applied by the camera over the image data does not follow the gamma law, in fact it does not follow any standard compensations (e.g. the CIE slope limited gamma function). Since hues are the mixture of the three primaries they are shifted because of this inconsistency.
To make it yet more difficult the compensation function is quite different between +/-0 and +1EV exposure compensation settings. (I not yet tested other exp.comp. values).
The Q-60 was shot at a repro-stand, using 5400K fluorescent continuous spectra lighting (Dulux/12). Please click on the icon images to see the large version, viewing only the icon images does not tell all.
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Olympus
400z photo 1:
Mode: SHQ, directly
from camera The histogram ends at level 210. Color are strongly saturated, intensity range is incorrect (notably in shadows) and large hue-shifts are readily noticeable. |
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Olympus
400z photo 2:
Mode: SHQ directly
from camera Histogram is properly full. All the errors of photo 1 are still there, only in lesser amount. |
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Nearly
calibrated version of photo 2.
Photo 2 was corrected in Photoshop using an action that was created according to an ICC/ICM color profiler information. After the correction gamma 1/2.5 was applied for viewing with uncalibrated PC system. It still needs some work but already shows that it is possible to recoverer the original scene information. Required de-tweakings are rather heavy, some artifacts are introduced. |
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Canon shot:Canon EOS*DCS*3 photo of Q-60 target,linear acquire, gamma 1/2.5 applied for viewing with uncalibrated PC system. This photo was taken at the same repro-stand setup as the Olympus images above, only the camera was changed to the lift. |
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What the Q-60 actually
looks like:
linear acquire, gamma 1/2.5 applied for viewing with uncalibrated PC system This shows rather faithfully the appearance of Q-60. |
Please Olympus give us linear acquire, without color/hue and intensity cranking.
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