[MF3D.FORUM:311] Re: 1/30 voodoo (Oy!)

[Tom Deering <tmd@xxxxxxxxxxx>]

On 3/26/00, Bill Glickman wrote:
>John B
>
>I read the section on your web site that talks about the 1/30 rule....  you
>explain below a more accurate rule would be 1/(lens fl) ... for 35mm.  So
>how exactly would this adjusted rule apply for MF stereo?    1/(2xfl) ????

Your interpretation is not quite right, Bill. The idea is to use 
1/focal length for *any* lens, not just 35mm. This makes the "rule" 
less wrong. :)

1/35 for a 35mm lens, (normal for 5 perf),
1/50 for a 50mm lens, (normal for 8 perf 35mm film),
1/75 for a 75mm lens, or
1/80 for a 80mm lens.

75mm and 80mm are often the "normal" lens on MF cameras. (The term 
"35mm" is often confusing, because it can refer to a lens, *or* a 
popular film format, as you can see above.) The focal length is 
marked on your lens.

But this only fixes one flaw in the 1/30 "rule", which also wrongly 
takes for granted that infinitely distant objects are in the frame. 
Not everyone shoots this kind of picture all the time.  90% of the 
time, I do not.

This thread was (re)started by someone wanting to shoot closeups. 
Any form of the 1/30 rule says that closeups are impossible, which of 
course is not true.

Tom

http://www.deering.org