What type of lens will auto-focus on Nikon bodies without a focus motor?
I have a Nikon D5000. For Nikon Lenses I know that I have to buy ones that are AF-S. Easy enough. But when it gets into third party lenses things get murkier.
When looking at off brand lenses, is there an easy way to determine if they will AF on my camera or not? Is there a similar designation to AF-S for Sigma, Tamron, etc?