That dark panorama ....


The images for the sunset pano were all taken at identical (low) exposure level,
such that the sun didn't saturate too much.
Given the sun's very low position, this had the consequence that most of the pano is very dark:



Sunset pano, without histogram adjustment.


In order to reduce the extreme dynamic range, I used histogram adjustment to 'boost' the dark regions.
This mimics the behaviour of the human eye, which quickly adjusts to variations in brightness.

The images were 8-bit, JPEG-compressed. As I learned the hard way with this panorama, 8-bit is insufficient.
Several pixels have zero-values for either the red or blue components, but not for the green component.
That is due to the CCD sensor of the Minolta 7D, which has a 1:2:1 ratio for the number of red, green and blue
pixels (many other cameras use same type of Bayer filtering).
Therefore, histogram adjustment always boosts the green pixels, but zeroes in red and blue channels remain zero.
This gives the pano an unnatural green tint.
Furthermore, the low number of bit levels results in a noisy appearance.

To avoid this problem, it is better to use RAW mode (12-bit, uncompressed) in any situation with high dynamic range.
For information about Minolta RAW, see this site.




Sunset pano, same as shown on Tenerife page.


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[Images are copyright P. van de Haar. This page was last updated on November 15, 2008]