No! No! Nothing scary.
The hyperfocal point of a lens, given a focal length and aperture size, is the point of focus where everything, from that point onwards, is in focus.
This is a technique that landscape photographers use to ensure that they have maximum DOF.
The formula for this is as follows:
H = (F * F)/(A * C)
Where
H = Hyperfocal Distance
F = Lens' Focal Length
A = Aperture Size
C = Circle of Confusion (For Nikon DX sized sensors this is 0.02)
So in the example I gave TMC above, if I wish to set the lens at 12mm and f/4, then I need to focus at 1.8m:
1800mm = (12mm * 12mm)/(4 * 0.02)
If I am using 20mm at f/4, then the hyperfocal distance is 5m and so on.
I usually carry a laminated chart with me with these numbers all laid out in a table. I know you can buy a
Nikonian T-Shirt that has this chart printed on it.
The reverse way to use this chart is as follows:
If you wish to take a shot with an 18mm lens that needs to have everything from 2m in front of you in focus, then you'd set your aperture to f/8 and focus at the 2m mark.
A = (18mm * 18mm)/(2000mm * 0.02)
This shot below was taken using hyperfocus with the 12-24mm Tokina set at 12mm, f/4 to focus at 1.8m:
Notice the DOF dispite the f/4 aperture setting. The advantage of using hyperfocus is that you don't have to worry about your camera not being able to lock-on and focus.
Hope this helps to make it less confusing and scary.
Cheers,
Matt