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Old 02-18-2009, 08:32 PM   #20 (permalink)
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Join Date: Aug 2008
Location: South Dakota
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WonderWagon - '94 Ford Escort LX
Last 3: 51.52 mpg (US)

DaBluOne - '99 Ford Escort SE
90 day: 48.97 mpg (US)

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Quote:
Originally Posted by NeilBlanchard View Post
I would use DataCAD to trace a polyline on the telephoto picture, and then measure the area with the handy Measures menu...report it in square meters or square feet; no problem. Here's two examples using the Aptera; the one on the left is a perspective distorted rendering, the one on the right is a pretty long shot of an actual vehicle:

Using the area from the long photo, the Aptera 2e has a CdA of 0.277 meters. (The hatch grid is 12" squares, btw.)
What would the numbers be if you had corrected the picture for lens distortion prior to working in DataCAD?

I took the long shot and based on the pole (tree?? Note curve relative to the straight blue line I added) on the left and corner of the building on the right, I applied correction for pincushion distortion. Would the DataCAD numbers come out the same for the corrected shot?

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