THE DIAGRAMS (right)
1. To provide an accurate sense of scale to such items as wheels affix with tape or Blue Tac an object such as white plastic ruler or piece of card that has clearly marked measurements in dark ink near the centre of the area photographed. A post-it can also work well as shown on the wheel tmage.
2. To minimise perspective, use the zoom on your camera and stand a suitable distance away, photographing the subject square-on.(See diagrams D to H below right)
3. Take shots at different heights , keeping the camera parallel to the ground.( D to H )
4. If using a digital camera, take as many pictures as your patience can bear, burn to CD if you have access to a PC. (From my point of view I would rather have too much reference material, than not enough.)
Diagrams A & B, top:
Typically, photographing a wheel
Diagrams C - K,
This is length one has to go to if you need to photograph the whole side of a car.
Diagram C' although may not be completly useless, on its own would be insufficent and may be misleading.
Diagrams D to H' zoom lense, square on about 2 car lengths away. Useful, accurate information is obtained, especially if an assitant fixes a ruler suitable object to the car at the centre of each shot.
Unfortunately I have apply the same technique horizontaly and take up to 40 shots of one side, of front and of rear when first creating enough information for the original drawing. Together with about 100 measurements of the whole car. I can only imagine the speculation that arose as to what owners and me were up to while undergoing this task at classic car rallies and in public car parks!
Diagram K - from each corner, three quarter, wide angle or normal lens, similar to A but of greater value as it shows depth, especially as B' to F' pictures may contain optical illusions from reflections or shadows. Four shots required. If its a car you no longer own its quite likely that this type of photograph is all you have. A front three-quarter view shot of this kind is similar to what people only take when they haven't read this page!
Photographs provided by you may only be sufficient in providing information fo altering existing drawings and possibly not creating new ones. New drawings require comprehensive measurements, research and studies.