John Kung

I promised in my last post about my Nikon PC-E 45mm tilt/shift lens that I would talk about using camera movements, so here it is. Camera movements aren’t very commonly used any more, but they are tremendously powerful and It’s worth shining a light into how it can work for your photography.

Rise, fall and shift are pretty simple concepts, and are well explained in the Wikipedia article on the View Camera. Tilts and swings, however, are the two that are most confusing and is worth exploring. Technically, pointing the lens up or down is a tilt, while moving the lens left and right is a swing. Conceptually it is the same thing, just on a different axis, and for the purpose of clarity (and betting that there are more of you reading this who have tilt/shift lenses for 35mm rather than a view camera) I’ll refer to it as tilt.

The Concepts Behind Tilts

In practice it’s not really very difficult to use tilts, but the concepts are sufficiently different to be confusing. I won’t go into a huge amount of detail because there are better articles online, but I think it can be boiled down to the following points. Skip to the next section if you’re not interested in the concepts and just want to get to the practice.

1 – The “Planes”
With every camera there are a number of areas that we can think of as a flat surface, or plane. At the back we have the “film/sensor plane”, where the lens sits is the “lens plane” and the thing you are photographing is the “focal plane”. On a normal camera all these planes are parallel to each other. But when you introduce tilt or swing into the mix, it makes the lens plane intersect with the sensor plane, which in turn means the focal plane also intersect, so the three planes meet at one point (this is called the Scheimpflug principle).

This is what actually happens when you apply tilt.

2 – The more angle of tilt, the more the focal plane also tilts.

The relationship between the lens tilt angle and the focal plane.

The focal plane tilts at a faster rate than the lens, so a small amount of lens tilt can have a substantial impact on the focal plane. In many instances it only takes a couple of degrees of tilt to accomplish what you need.

3 – What actually happens when you change focus with the lens tilted.
At this point there I need to introduce one more plane: the “lens-parallel-to-film plane”. This is basically the lens plane without any tilt. This plane is important because when the lens is tilted, the point where the subject plane meets the lens-parallel-to-film plane becomes the hinge, and when you focus the lens the focal plane fans across the frame anchored to that hinge point.

This is completely unlike how focus normally works, where the focal plane moves closer or further away from the camera. In practice, you don’t need to worry about this because all you have to do is focus on the spot you’d like in focus, and it just magically falls in place. If you can’t seem to get everything you want in focus actually focused, it’s probably because you’ve set the wrong angle of tilt.

4 – Aperture and the Zone of Focus
With a normal camera your zone of focus (depth of field) is the area in front of and behind the focal plane (remember each of these planes are 2D, they are just imaginary lines — depth of field is the 3rd dimension, the “thickness” of the focal plane.) But when tilted the zone of focus is more of a cone where the tip of the cone is closest to the camera. The more you stop down the wider the cone is. This is especially important when you’re photographing something up close — just because you’ve applied tilt it doesn’t mean your zone of focus is wide enough to get all of your subject in focus.

Have I lost you yet? It takes a little getting used to, but once you’ve got the concepts down it’s much easier to pre-visualise your image and figure out how to set up your tilts.

How To Set Your Tilts

If you skipped the last bit or have already forgotten, don’t worry, because all you really need to know is the “J” Distance:

In short:
1 – decide what you’d like to have in focus
2 – work out an imaginary line where your focal plane should be
3 – imagine a line that runs straight down from the camera, and how far down it has to go before it meets the focal plane (this is the J Distance)
4 – check the J Distance against the chart below, which will tell you what degree you should set the lens on.

For my 45mm lens:
J = 2.6m = 1 ° of tilt (towards the focal plane)
J = 1.7m = 1.5 °
1.3m = 2 °
1m = 2.5 °
860mm = 3 °
740mm = 3.5 °
645mm = 4 °
520mm = 5 °
430mm = 6 °
370mm = 7 °
320mm = 8 °

These numbers came from an article called “Focusing Tilt Shift Lenses” by David Summerhayes on The Luminous Landscape. He has calculated the numbers for 24mm, 45mm, 85mm and 150mm lenses so have a look there for his charts. Thank you David for doing the math!

Application

Keep in mind that the goal of the techniques I’ve outlined above is to get your subjects in focus, rather than the selective focus effects that are most commonly associated with tilting. Being able to more selectively place your focal plane means you don’t necessarily have to just stop down in order to get the depth of field you need to have your subjects in focus. Imagine your family sitting at the dinner table for Christmas lunch. You want to get everyone in focus, as well as all the food, but without tilts you’d probably have to stop down to f/22, which introduces diffraction (in 35mm cameras), a slower shutter speed or a higher ISO (causing either subject movement or more noise), or you have to use flash on camera which has it’s own problems because those closest will likely be over exposed while those furthest will be under exposed. With tilt applied I can shoot at a reasonable aperture and still have everything I want in focus.

Notice in the crop how there’s sharp focus from the front edge of the the table to the striped shirt. Notice also how the feet at the bottom of the frame is out of focus. This was shot at f/5.6, with about 1.5 ° of downwards tilt.

The same principle applies in landscapes, a small amount of tilt will get the background at infinity and the area by your feet in focus, removing that “hazy” look in the far distance caused by being slightly out of focus (though it can’t do much to help if it is actually hazy!)

You can also use this to decide what to take out of focus. Consider this example:

With this image I used a swing to put the focus just on the centre of the frame, leaving the areas on each side out of focus. Click to see the full size image.

By applying a swing (to the left, at about 5 ° from memory) and shooting at a large aperture (f/3 in this example) I got a narrow zone of focus diagonally across the pavlova to put emphasis on the frosted berries on the top. You can see the cone of focus get wider on the right hand side of the frame, the table surface and the logo on the knife is clearly visible, while the plates on the left hand side of frame stays very much out of focus.

What about the “miniature” effect?

The simplest way of achieving the “miniature” effect is to tilt the lens in the opposite direction to your subject — so if you’re taking a landscape, instead of tilting the lens down to get more focus, tilt it up to get less. There’s less to think about here; more angle means stronger effect, and what you see is what you get — what you focus on is what will be in focus.

Keep in mind though, The miniature effect is stronger if you are further away from your subject, taking a shot of your friends lounging on the grass in the backyard when you’re standing in front of them won’t have the same effect as taking the same shot when you’re on the roof of your house. Being further away and using a longer lens really helps to compress the scene down and exaggerate the dollhouse look.

Wrapping up

I hope this post has helped clarify how tilts can be used. It really is such a useful tool that once you master it you’ll never want to go without it. But I want to really stress that this is just one of many tools in your arsenal — I have come across lots of images where too much tilt has been used, or used unnecessarily, or the effect has been used to the detriment of the image. Like any tool or technique, a bit of finesse (and moderation) goes a long, long way.

If you have any questions, sound off in the comments!