[MF3D.FORUM:323] Re: 1/30 Yes!

["Oleg Vorobyoff" <olegv@xxxxxxxxxxxxx>]

I ran my typical shots through the general formula in John Bercovitz’ paper,
http://werple.net.au/~kiewavly/bases.html.  Here are the errors in the 1/30 rule
applied to a 70mm lens:

Typical landscape with clouds - ˝%
Low landscape without clouds - 2%
Cramped view - 13%
Near detail - 9%
Closeup - 2%
Long Hyper -3%


The rule tracks remarkably well.  Correlation is just as good for all my other
lenses (45 to 420mm) once you apply the fl/70 factor.  The 1/30 rule tells you
almost exactly where your window will end up if you do not "cheat."  But I have
to admit, I cheat a little to a lot on most shots.  The 1/30 rule is just a
solid springboard.  Artistic considerations will dictate how far (or if) to
jump.  For example, the cramped view might look best without second guessing the
1/30 rule because exaggerating the depth could undermine the claustrophobic
aspect of the scene.

Details:

Typical landscape with clouds:
 Near point: 6 feet
 Far point: 100,000 feet (19 miles)
 True stereo base: 2.41 inches
 1/30 rule’s base: 2.40 inches

Low landscape without clouds:
 Near point: 3 feet
 Far point: 10,000 feet (2 miles)
 True stereo base: 1.18 inches
 1/30 rule’s base: 1.20 inches

Cramped view:
 Near point: 3 feet
 Far point: 20 feet
 True stereo base: 1.38 inches
 1/30 rule’s base: 1.20 inches

Near detail:
 Near point: 2 feet
 Far point: 15 feet
 True stereo base: 0.88 inches
 1/30 rule’s base: 0.80 inches

Closeup:
 Near point:  1 foot
 Far point: 10 feet
 True stereo base: 0.39 inches
 1/30 rule’s base: 0.40 inches

Long Hyper:
 Near point:  300 feet
 Far point: 100,000 feet (19 miles)
 True stereo base: 123.7 inches
 1/30 rule’s base: 120.0 inches

Oleg Vorobyoff