Bill Preston said:
You will also hear from those who only use a digital camera, and scale up from the photo.
Digital camera photos can be handy, but most would have to agree it is a "quick and dirty" method. Such images can be sufficient when photographed properly and used in conjunction with good reference measurements.
I can accept being accused as a control freak, but I just don't really trust others taking digital camera reference photos for me if the images are intended as a method to get "scale" out of something.
There's lots of mistakes that can happen when taking a reference photo. The camera lens may be zoomed out too wide, thus barrel distorting all of the subject matter. The image may not be taken straight on at the subject. Lots of people will just stand off at an angle from the subject, keystoning the image and making it pretty much useless.
Adobe PhotoshopCS2 has some nifty new tools for correcting keystoned images and correcting barrel distortion from digital camera wide angle lenses. Still, the tools aren't perfect.
Finally, digital cameras cannot escape the way perspective alters dimension and scale. Imagery in the center of the frame may be near correct ratio and proportion but anything out to the edges will be distorted. This is the problem that makes digital camera photos a poor guide for doing exacting vehicle graphics work. If you're needing something to fit vehicle contours to a precise level you'll have to work with accurately drawn templates. For an expensive job, you may need to develop your own just to be safe. We have the Pro Vehicle Outlines collection and some of the templates are not perfect.