I am hoping someone can help me decide between the Tokina 16-28 and the canon 17-40. (I have a Canon 6D). I will primarily be using this lens for real estate photography. I've done some research but I'm not super clear on a few things, 1. Do I NEED a fisheye to create virtual tours? Will either of these lenses work for standard interior shots AND to create a 360 virtual tour? Or do I need two different lenses? I understand that to create a 360 degree view will require multiple images stitched together. I am able to obtain either of these lenses used at a great price and that is why these are contenders on my list. Thanks in advance for your help. And I appreciate any other suggestions or tips.