http://www.ratical.org/ratville/JFK/images/Altgens.jpg
Viewing the above photo - note the motorcycle cop on the left of the
photo, apparently looking in the limo.  Note the shadow of this same
motorcyle in front of the limo.  Note the length of the shadow of the
motorcycle on the right for reference.  (Photo was taken at 12:30pm in
Dallas, Texas)  Is there a simple proof that
the motorcycle cop *must* be alongside the limo, rather than approx.
3ft to the side, and located *between* the limo and the following
limo?  (This is the primary question!)  The limo is 6.5 feet wide, and
21 feet long.  Camera is 105mm, and photographer stated that camera
was focused and shot at 30 feet.  This is disputed, and some maintain
that the camera is 60 feet away.  Is there any simple geometry that
can provide the distance?  Note, if the motorcycle cop is proven to be
alongside the limo at a camera distance of 60 feet, then proof of a
closer camera view is not needed.

I also note the distance between the cops on the right side of the
photo - and their apparent distance to the standing SS agents on the
followup - as drastically different from the cop on the left of the
photo - and *his* apparent distance from the standing SS agents on
*his* side of the limos.

I would prefer an answer from someone who's mathematically or
photographically inclined  (It's been suggested by some that
photogrammetry is required), and *NOT* from anyone with more than a
passing familiarity with this particular photo.

Benholmes--

It would be helpful to know what film format was used, i.e. 35mm,
large format etc and what f-stop was used also.

Herkdrvr

Benholmes,
I have been playing with my 80-200mm zoom lens. I am almost sure the
photographer was not 30 ft from the first limo.  That would have been
only 1.3 limo lengths away, making it unlikely that he would have been
standing on the street at that moment.
But more important, from my playing around, the field of the photo
seems maybe right for a shot at 60 ft with a 105mm lens (Or has there
been a confusion of
30 ft and 30 yds?)
I am sure this can easily be checked by a better knowledge of lens field.
Do you know if the photo has been cropped, or is this the full negative? 

The cop on the right:  just a bit of his shadow can be seen at the end
of the limo's bumper.  As we can see best from the shadows of people
on the right of the photo, the sun is shining from a little behind the
photogragher's right shoulder.  Looking at the other cops, who are
riding parallel to the one on the left, we note that their shadows
"trail" them slightly, as must that of the other cop.  He does appear
to be very close the leading limo, but if he were, we could not see
his shadow, so he must be about the same distance from it as the
nearest other cop is to the following limo, which would be logical.
If he were further back, we could not see his shadow.

Described another way, if we draw a line horizontally across the photo
from his shadow, we can visualize about where he would be on the other
side of limo, about level with the rear wheel, putting the tip of his
shadow on a vertical line with that of the other cop's (under the feet
of the first SS man).  Now we see (can envisage) that he must have
been riding with his front wheel ahead of the limo's rear wheel.


Does that help you?  You can probably try cutting up a copy of the
photo and playing around with this:  cut out the cop and his shadow
with the fender and placing on the other side.

Good luck.   As you know, this is just a comment and not an Answer to
your question, which only a blue-named Googles Researcher can post.
Myoarin

It should be possiable to determine the position of any of the objects
in your photo by knowing the position of the Sun, hense the time, the
facing of person in question, in direction (i.e. 180 degrees or due
South) and the length of the shadow of the object relative to its
height.  I would be surprized to hear anyone suggest that they are not
at least passingly familiar with this photo.