i can't place it closer to the ground, actually the camera is 40meters far from the enter and apprx 8meters high (so i can't climb every 5 minutes to make tests...) & i'm using a 5-50mm lens (same as the older camera), i had tried with 2.5meters hight but some burglars broke it and the results were not good, as i'm a ski resort, i can't place it under the vehicule due to the snow
some other things that i didn't mention:
i'm using an halogen spot to highlight the plates when cars are enterring the parking,
i have a short laptime to catch a clear picture (there is approx 4seconds between the entering point and the exit of the field of view, i have between 1 and 2 seconds before the car speedsup), i used to have a lot of motion blur with the old camera, i don't know if i should set the shutter to AES, Flikerless or to maintain it fixed at a certain speed, i made a test with a fixed shutter (1/250), it seems to avoid motion blur but the picture still really awfull...
for curious ones, here is a link to the camera manual:
http://www.burlecctv.com/pdf/LTC0495.pdf