The Canon 17mm f/4L TS-E Tilt-Shift lens is a manual focus lens primarily designed with architecture in mind. While it can be used in portraiture and landscape to isolate focus, it’s primary use in architectural photography is to make sure keystoning remains straight throughout the frame. For those who aren’t familiar with the terminology, keystoning refers to keeping vertical lines on buildings and walls perfectly straight from top to bottom. This removes the lens distortion so that images appear as the human eye will see the view if they were standing in that space. For Real Estate photography I find this very beneficial because you don’t want a potential home buyer to see tilting walls. It gives the space a sense that there is something wrong, it brings the wrong type of attention to the space. A potential home buyer may not schedule a visit to the home if they cannot tell if the home has structural issues or not. By making certain that your keystoning is correct, your image will show the space the same way the human eye will see it when the potential buyer is there in person. This single aspect of a professional image will make a listing have more clicks and more in-person views which should lead to quicker sales or rentals of your properties. The 17mm lens is an extreme wide angle lens that produces very little distortion when accurately level. On a full frame camera it is capable of capturing even the smallest room from corner to corner. The “Shift” feature which allows you to change the position of the main glass element to the relation of the cameras sensor allows you to frame your interior space precisely how you want to show it whether your tripod is 12 inches from the ground or 8 feet in the air. The precision control you have over your final image is unmatched by a regular camera lens. Want more information or have a specific question or comment that I can help you with? Feel free to comment below and I’ll do my best to help you out. Happy Shooting!