Re: [photo-3d] Re: Camera separation in stereo photography

["don lopp" <dlopp@xxxxxxxxxxxxxxx>]

Why guess-as I have said before , From my experience there is a direct
relationship between lens focal length and the stereo base required.for a
50mm lens a stereo base of  1 foot will cover 50ft to infinity, a base of
one half foot covers 25 feet to infinity  and a base of 1/4 ft[3 inches]
covers 12 ft. to infinity. For a 135mm lens a one ft. base covers 135 ft. to
infinity and a 1/2 ft. [6 inch]base covers  70 ft. to infinity, a 1/4 ft
base[3 jnches] covers 35 ft. to infinity. for a 28mm lens a one foot base
covers 28 ft. to infinity-a 6 inch base [1/2 ft] covers 14 ft to infinity, a
3 inch base [1/4 ft base] covers 7 ft. to infinity , ETC This works for me ,
but these numbers are a little bit conservative but are easy to remember
especially for me as the methadone pain medication keeps me a bit spaced
out-it took me 32 miutes to type this short message.Don.
----- Original Message -----
From: "Oleg Vorobyoff" <olegv@xxxxxxxxxxxxx>
To: <photo-3d@xxxxxxxxxxx>
Sent: Saturday, June 24, 2000 11:52 AM
Subject: [photo-3d] Re: Camera separation in stereo photography


> Brian Reynolds wrote:
>
> >There is no general optimum camera separation.
>
> Agreed, but I have found that a very good starting point is a separation
that
> makes full use of the depth between the mounting window and optical
infinity.
> Since I use lenses ranging from super wide angle to macro to long
telephoto,
> 65mm separation is almost never the best.  Full depth, on the other hand,
is
> close to optimum for at least 90% of my shots.
>
> >Most of the time I just guess at camera separation.  I like playing
> >with the formulas, and occasionally precompute the separation, but
> >it's a pain to do it in the field.
>
> And strong possibility of computing error besides.  I'd rather devote my
creaky
> old brain cells to the composition, not to technicalities.  So I have a
no-think
> method for determining separation.  I carry a set of cards, one for each
lens,
> each with a look-up table listing separation for a given window location
(and
> far point at infinity).  First I look at the scene with both eyes and
decide
> where the frame (window) of the picture should end up.  Okay, this part
takes
> thinking, but if you have no idea of where your window will be you really
have
> not thought through your stereo composition.  Then I look up the required
> separation, and complete the shot on autopilot.
>
> Oleg Vorobyoff
>
>
>
>
>