🚀 go-pugleaf

On my earlier post for sources of racing car drawings, Bill Soll (name may
not be correct, I goofed in saving message) suggests drawings from photos.
I have done this, and I might point out some of the pitfalls to others who
try it.  The problem comes when you do not know the exact vantage point from
which the photo was taken.  This is primarily true for quartering shots.

If you are taking the photos themselves, fine, there are some things you can
do to ease the problem, which I have found work.  I have used these ideas
on both cars and boats.  First, use as long of a focal length as possible
(limited only by your ability to back up and still take in the whole
vehicle.  This reduces the perspective effect (makes it more like an
isometric).  Shoot from as perpendicular as possible to side and front
(usually not possible to get top view!).  This is important.  Aim for a
point in the center, and stay square on.  This also reduces perspective.

For getting absolute dimensions, two methods are possible (photo only
normally gives relative dimensions).  One, take a tape measure along
and make one measurement for each view.  Two, if this is not possible,
measure distance (or estimate as closely as possible) from vehicle to
camera point, and record focal length.  Similar triangles can then be used
on print or negative (oh yes, on print carefully measure enlargement ratio)
to measure points on vehicle.