Big Ben's Panorama Tutorials

Colour Correction and Digital Cameras

Relative  exposure (f stops)	Original Image	Reference Image	Corrected Image
-3
-2
-1
0
+1
+2
+3
+4

Some things to note:

• The shadow detail is better in +1
• The highlight detail is better in -1
• The highlight detail in the corrected +1 image has already been reduced to noise, and spreads rapidly across the image as exposure is increased.
• Shadow detail can be extracted from underexposed images but the colour begins to degrade at -2 and noise is unacceptable at -3.

Film vs Digital.

Below is a comparison of the corrected images from both tests. While the film image appears to have a lower contrast, this is because it contains far more detail in the highlights and shadow. The equivalent detail in the digital images is spread across exposures from +- to -1 (see above).

The biggest difference between film and digital is that film does not have a distinct cut off of detail at under and over exposure. The information in under and over exposed regions is somewhat compressed, but it is still there. Once a digital image is overexposed, there is no information left to retrieve.

Relative  exposure (f stops)	Corrected Image	Corrected Film Image
-3
-2
-1
0
+1
+2
+3
+4