But it is difficult to use and it needs a lot of practice. It brings almost total control over the plane of focus. The tilt function allows a unique way of photographing. Due to the orientation of the plane of focus I managed to achieve a very small depth of field. But it is not tilted the same way as the plane of focus.Ī forest with bluebells, shot with a Canon TS-E 17mm f/4L tilted upwards. When the plane of focus gets tilted, the depth of field area will also be tilted. We all have seen such drawings about depth of field. Having the plane of focus exactly parallel to the sensor you know that the depth of field is also parallel to the sensor. Although it is a bit more complex than this, I won’t get into the details on how depth of field works. What if you introduce a larger depth of field?ĭepth of field is an area in front of, and behind the plane of focus that is also in focus. As you have seen, the pieces of paper are in focus, but the top of the books are out of focus. Up until now I have ignored depth of field and regarded the plane of focus as the only thing that is sharp in the picture. But with tilt the top of the book cover is completely out of focus, while the pieces of paper are in focus from front to back. In a normal situation the plane of focus is vertical, just like the sensor orientation. But also the focal length of the tilt-shift lens will determine the amount of tilt. The more you tilt the lens, the more the focus plane will tilt. I won’t try to explain the physics behind this principle, but it is imperative to understand how this principle affects the place where the focus will be. It tells us how much the focus plane will tilt. This effect is called the Scheimpflug Principle. If you could tilt the lens far enough, in theory, the focus plane would even become horizontal. As you can see in the drawing below, the focus plane will tilt in the same direction as the lens. The focus plane will no longer be parallel to the sensor plane. What Happens When the Tilt-Shift Lens Is Tilted?īy tilting the lens something strange happens. I used the Canon TS-E 24mm f/3.5L II for this setup with an aperture of f/3.5 to keep the depth of field at a minimum, but it also applies for every other focal length. Just imagine the plane of focus to be a flat surface that is exactly parallel to the sensor. But no matter how large or small the depth of field is, it is always parallel to the sensor, just like the focus plane itself.įor now, I will ignore the depth of field. That is the reason why I bought these lenses.A normal situation shows a plane of focus that runs parallel to the sensor plane.īy closing the aperture it is possible to get an area in front and behind the focus plane within an acceptable focus. Also for real estate photography, these lenses are perfect. Just keep in mind to capture enough extra space to allow cropping.īut if shoot a lot of buildings or other objects that have vertical lines and you need a perspective distortion-free capture, it might be worth investing in such a lens. If you have to correct perspective distortion just once in a while, it might be perfect to do so in post-processing. Nevertheless, most tilt-shift lenses are much too expensive to buy without a good reason. I used the Canon version for this article. Of course, Nikon also has its own versions. But perhaps there are more alternatives available. Laowa is one brand that comes to mind, just like Samyang. But it is possible to find some budget version on the market. Who Will Benefit From the Shift Function of a Tilt-Shift Lens? But there will be some degradation in the parts that have been affected by the correction, although I don't think you will notice in most cases. The end result after perspective correction looks great. This is shown in the before/after image below. This can be done by shifting the lens relative to the camera, in this case, upwards. You just have to place the part that will be registered by the sensor in the correct location. Because of the large image circle, the whole building or tree will be visible within that image circle. Shifting To Prevent Perspective Distortion At the same time, there will be too much ground or pavement in the frame. That is the moment when the shift function of the tilt-shift lens comes in handy. The vertical lines of buildings will be vertical, but the building might not fit into the frame. So, if you can hold your camera perfectly horizontal, the perspective distortion is absent. There might be some regular barrel distortion, but that is due to the physics of the lens. If you hold your camera perfectly horizontal, you will see the lines become normal again. By tilting upwards, the perspective distortion is huge. With a 17mm wide angle lens, this is the result with this building.
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