Figure 10.8

Matte boxes like this one by Chrosziel fit onto the lens and let you change filters quickly and easily.

Figure 10.9

Filters, like these by Schneider Optics, are designed to simply drop into the frame of the matte box.

A shallow depth of field can look very pleasing but it means that setting the focus is crucial. If you don’t know much about setting focus manually, read on.

Measuring and Pulling Focus

If you plan to project your video in a theater, proper focus is critical. Things that look focused on a small LCD screen might, in fact, be slightly out of focus. When these images are blown up to the big screen, the focus problems will become visible. Nowadays, even a large TV monitor can expose focus problems.

220 The Digital Filmmaking Handbook, 4E

Video assist monitors like the ones shown later in this chapter can help, but even they are very small when compared to a large flat panel TV or a screen in a theater.

The easiest way to keep your footage in focus is to shoot in bright daylight with a high f-stop. Shooting with a wide-angle lens also helps hide any focus or depth-of -field issues, because things in the background will likely appear smaller, due to the wide angle. So as long as you don’t have anything coming too close to the camera, you can rest assured that everything will be in focus.

Unfortunately, the look of a wide lens and bright daylight isn’t always the ideal choice, aesthetically. If you’re shooting mostly at night, or you want a shallow depth of field, chances are high that you’ll need more advanced techniques for setting focus.

In Chapter 7, “Using the Camera,” we discussed the basic technique of zooming in or using focus assist to set the focus by eye. This method will work, and it is sufficient for a project that will be viewed on a small scale, such as a Web video. But for projects destined for bigger screens, the only safe way to set the focus is to measure it. Measuring focus takes the guesswork out of the equation and means that you can feel confident in your footage, even if you can’t judge the focus by eye.

Measuring Focus

If your camera lens has a focus ring with distance measurements marked, it can measure the distance between your subject and the camera to ensure perfect focus. Most cameras have a mark somewhere on the camera body to indicate where you should measure focus from— check your camera manual if you can’t find it. In the case of digital cameras, the focal plane is where the image sensor is positioned. In some instances, focus is measured from a mark on the lens instead of the camera body. Note that you can’t be sure of the focus markings on your lens or camera unless you’ve tested them and found the marks to be accurate. To measure focus, a standard measuring tape is used to check the distance between the mark on the camera/lens and the subject in the shot. Often, the biggest challenge in measuring focus has to do with figuring out where the actors will end up during the course of a shot and also the fact that you may need to plan on several points of focus during a shot.

Pulling Focus

Everyone’s heard of actors “missing their mark.” The mark is actually the focus mark. The assistant camera operator will put marks with colored tape on the floor (out of view) and the actors will know to hit that mark for a certain line. There will usually be at least two marks for each actor in every shot, if not more. Once the marks are established, focus is measured for each mark and then focus marks are recorded on the lens, either using a Sharpie marker on a piece of paper tape or using a china marker on the follow focus mechanism (Figure 10.10).

During the take, the camera assistant will adjust the focus, following the movements of the actors—a process called pulling focus. Pulling focus requires choreographing the movement of the actors and the camera during blocking. There is an art to pulling focus, especially when shooting with a shallow depth of field. A rack focus is an intentionally visible shift in focus when there are two subjects in the frame and the focus is pulled from one subject to the other.