What is Hyperfocal Distance? Common Digital Video Camera Technique
Understanding Hyperfocal Distance
Hyperfocal distance is a commonly used technique on digital video cameras, though it can be a complicated aspect to understand. Take any particular lens, with any f-stop or or relative focal length, and look at the nearest distance setting that lets a far limit to the depth of field to an infinite level. This closest distance setting is referred to as the hyperfocal distance. This hyperfocal distance is set, then you are can see the depth of field go from half of the set distance to infinity. Your camera should list this as an actual setting, though many require you to calibrate the zoom manually to get correct focal length.
Using Hyperfocal Distance on Video
To set hyperfocal distance you simply do this with standard calibration of zoom. This means that everything between the farthest point and the half way point will remain in focus. You will only have trouble if their is an object that ends up coming too close. You can often deal with a balancing of a far away object and a close up object by a mix of framing, effects, and lenses.
For example, you could use a spit diopter to capture both the distant image and the close up one. You could also rack focus to transfer the focus from one object to the other. You may even want to simply have your movable object back up into the hyperfocal area.
Wide Angel Lenses
Wide angle lenses are often already set to hyperfocal distance. This is usually why they do not vary a great deal and end up with a stable image on the far object. Try it with different wide angle lenses and see how much you have to set hyperfocal distance.
Hyperfocal Distance Tables
There are many available informational tables that will give you the approximate hyperfocal distance for different lens aperture readings and lens size that you are using. These numbers then usually will correspond to a circle of confusion, then you will be able to find your appropriate position. These are not always completely accurate and you should make sure to check it in practice before relying on it completely. You should always trust your eye before any numerical setting.