Hi, I am totally clueless with photography but my wife is a keen photographer. She did mention a while ago that she would like a 18-300 lens for her Nikon D7200 to use as an all round lens and now she has a birthday approaching. I have been looking around and have been trying to research the Nikon AF-S DX NIKKOR 18–300mm f/3.5–6.3G ED VR, the Tamron 16-300mm F/3.5-6.3 Di II VC PZD MACRO and the Sigma 18-300mm F3.5-6.3 DC Macro OS HSM. Any advice on what lens would be preferable and I am happy enough to pay the extra for the Nikon if it is worthwhile to do. Thanks in advance.