Hi Klaus,
since I did tried once that luff-curve-outside-the-track-matching method, I tend to agree with you saying it end up with an horrific prebend and that why I did not keepted theese settings. Now if I match the sail with the luff inside the track, I guess I have to measure the chord to depth ratio of the sail. What would be good numbers for flat sail and full sail? Should theese numbers be uniforms troughout the sail?
Now, stupid question; Can theese sail+mast pictures be taken on the beach. If not actually sailing, are they of any interest? Is putting the boat on its side would help? I' m afraid of your answer but I had to give it a try.