Using lens tilt to isolate focus

Tilting the lens to control focus

One of the principal uses of a lens with a tilt feature is that once you move the lens on its axis, the plane of focus ceases to be a simple flat plane in front of your camera.

We recently shot a collection of interior photos for a client creating a brochure for a commercial property. They wanted a range of ‘detail’ shots to go with the normal interior and exterior photographs. Some of the full set of photos are in a collection on this site.

The location was  a city centre bar, in a long thin building.

By swinging the lens to one side, without moving the camera, the sharpest areas of the image are now on a vertical plane running from near left to far right in the scene.

Tilted plane of focus

I’ve annotated this image to show where this plane runs.

Note how sharp the wooden bar top and front of the beer pumps are, but the bar behind is gently softened, emphasising the pumps.

The plane runs all the way to the entrance, so you have sharp focus leading the eye into the image.

Note too how the far right of the image is also slightly softer.

The plane of sharp focus can easily be shifted so that it runs horizontally or at any angle.

The tilting of the focal plane can be useful for taking photographs of floors, ceilings and walls, where a normal photo just couldn’t keep everything sharp if you are close to the subject.

An example from underneath Leicester railway station shows the whole of the front of this electrical control unit in focus.

If you need such a shot, there is no easy way to recreate it without using specialist lenses.

One thing to note is that the depth of field close to the camera is very thin. Think of the sharp zone as a wedge that thicken the further away the subject.

Of course when it comes to creative images, you may not want all that sharpness.

This view of the electrical equipment uses a fisheye image processed to correct vertical lines. Note how only the displays are really sharp.

At Northlight I’m happy taking either sort of image (or both).

We’re always keen to discuss with clients (or their design teams) all the different creative options we can offer, and maybe even suggest a few you’ve not seen before…

There are many more technical articles about specialist lenses on the main Northlight images web site