Over-exposure- Significant decrease in contrast, particularly in bright colors
- Loss of color saturation
- Loss of highlight transitions in the reds in bright light at even +1 over
- Insignificant color shift
- +1 provides a nice boost in shadow detail
Under-exposure- Significant increase in contrast, again the affect is more pronounced with bright colors
- Exaggerated saturation
- Significant color shift towards the magenta end
- Insignificant increase in highlight texture
Discussion
As mentioned in various earlier threads and elsewhere on the Web, this film seems to have its sweet spot at the rated ISO. That being said, there is some benefit to mild over-exposure, though there may be a loss of tonality for some high values. 0.5-1.0 stops over at the max would be my suggestion. The loss of contrast and tonality with additional overexposure beyond +1 is unacceptable.
Edit
I thought it useful to add these two comparison crops from the 1+ sunny (on the left) and ISO 100 sunny (on the right) shots. They show the tonality and contrast effect of mild overexposure quite nicely.
Here is a comparison of the +1 sunny (top) and ISO 100 sunny (bottom) histograms from Lightroom...
End edit
In these tests, I was unable to produce the bizarre fluorescent reds seen on some posted photos (mine included). An early comment to this thread indicated that "none" of the colors look right. I agree that some tweaking would be in order for both the reds and the blues in the scanner settings. The scanner was set to default response curves and has not yet been dialed in for Ektar. The expected colors:
- The bandana is new and is bright true red
- The Adidas shorts are a true royal blue
- The glass dish is a deep emerald green
Of the three colors, the green is the most correct. The blues need a saturation bump while the reds need a mild shift in hue. I think I may have a shot of the setup taken with the K10D. That should give reasonable a color reference if I can find it.
Steve
Last edited by stevebrot; 07-15-2009 at 10:54 PM.