Nikon's venerable 12-24mm ultrawide zoom has the benefit of a reasonably fast f/4 aperture that remains constant throughout the zoom range. By contrast, the newer 10-24mm lens has a variable f/3.5-4.5 maximum aperture but, crucially, it extends the zoom range where it matters most: at the wide-angle end, effectively boosting it to an equivalent 15mm compared with 18mm for the older lens.



Link: TechRadar