The equivalent on Full Frame would be 24 2.8, but for APS-C you would have to go wider, there is a nikon 18 20 1.8, its new and expensive, there is also the sigma 18-35 1.8, but that lens is only for aps-c. Anyway, I think that look kinda got old in 2010 with the 5D and the 24 1.4...