How to Rack Focus on the Bolex
- 1). Identify the focus ring on the lens. This ring will usually have one or more marks that line up with distance indicators printed on the body of the lens. Do not confuse the focus ring with the zoom ring, which may also be nearby. A focus ring does not change the magnification of the image, only the sharpness.
- 2). Measure the distance between the first subject and the Bolex's focal plane. If the subject is a person's face, begin measurement from the eyes. End the measurement just behind the camera shutter, where the film lies.
- 3). Turn the focus ring until it aligns with the distance mark approximately equal to your measurement.
- 4). Zoom in as far as possible on the subject, if you are using a parfocal lens, a lens which holds its focus when the focal length is changed. If you are using a varifocal lens, or a lens which loses its focus when the focal length is changed, skip this step. If you don't know what kind of lens you are using, zoom in and out on the subject and see if the focus changes.
- 5). Adjust the focus by eye finely.
- 6). Zoom back out to your desired framing if you zoomed in on your subject using a parfocal lens.
- 7). Mark this focus point on your lens with a grease pencil, or wrap a strip of gaffer's tape just outside the ring and mark it with a fine-tipped pen or marker.
- 8). Measure the distance between the second subject and the Bolex's focal plane using the same technique as before.
- 9). Focus the lens.
- 10
Mark this second point on the lens. - 11
Return to the starting focus point by aligning the mark on the focus ring with the first focus mark. - 12
Get your focus-puller to quickly turn the focus ring so that it lines up with the second focus mark.