Sigma 12-24mm EX DG vs 14 3.5 (older model)
I bought an old 14 mm f3.5 because I was favourably impressed by Tom Hogan's review and the price was very good (The barrel was worn but lenses were OK). A friend of mine has the new Sigma 12-24 EX DG so we tried to compare the two lenses. He borrowed me the lens and I shot with my D70 one shot just after the other , so that the differences in colour rendition are due only to the lenses. For your knowledge, the walls of the watermill were white.
Photos are jpegs converted from NEF without any post processing.
Data for the 12-24 Data for the 14 f3.5:
f l. 12mm, 14mm
time and aperture: 1/60 f.11 1/50 f.11
Aperture priority Aperture priority
ISO 200 ISO 200
The results:

A 100% crop from the 12-24:
And from the 14

There are visible differences, indeed...