Weird Vectorplot

I would like to Plot a simple Vector Field, all vectors normalized to one. If i for example take a evenly distributed sample of the field and plot it with the ListVectorPlot function, i get a plot where position and length of the vectors differs (strongly) from the data:

field={{{{2, 0.}, {1., 0.}}, {{2, 0.1}, {0.982017, 0.188795}}, {{2,
0.2}, {0.951929, 0.306318}}, {{2, 0.3}, {0.917796,
0.397053}}, {{2, 0.4}, {0.8818, 0.471624}}, {{2, 0.5}, {0.845307,
0.534281}}}, {{{3, 0.}, {1., 0.}}, {{3, 0.1}, {0.976522,
0.21542}}, {{3, 0.2}, {0.960011, 0.279961}}, {{3, 0.3}, {0.942248,
0.334916}}, {{3, 0.4}, {0.923184, 0.384358}}, {{3,
0.5}, {0.903192, 0.429238}}}, {{{4, 0.}, {-1., 0.}}, {{4,
0.1}, {0.889109, 0.457696}}, {{4, 0.2}, {0.950692,
0.310138}}, {{4, 0.3}, {0.947352, 0.320194}}, {{4,
0.4}, {0.938342, 0.345709}}, {{4, 0.5}, {0.92731,
0.374295}}}, {{{5, 0.}, {-1., 0.}}, {{5, 0.1}, {-0.923402,
0.383834}}, {{5, 0.2}, {0.902614, 0.43045}}, {{5, 0.3}, {0.941445,
0.337166}}, {{5, 0.4}, {0.943004, 0.332782}}, {{5,
0.5}, {0.938529, 0.3452}}}, {{{6, 0.}, {-1., 0.}}, {{6,
0.1}, {-0.992932, 0.118681}}, {{6, 0.2}, {0.508632,
0.860984}}, {{6, 0.3}, {0.920174, 0.39151}}, {{6, 0.4}, {0.941035,
0.338309}}, {{6, 0.5}, {0.943283, 0.33199}}}, {{{7, 0.}, {-1.,
0.}}, {{7, 0.1}, {-0.998006, 0.0631237}}, {{7, 0.2}, {-0.81308,
0.582152}}, {{7, 0.3}, {0.856928, 0.515436}}, {{7,
0.4}, {0.932176, 0.362005}}, {{7, 0.5}, {0.943793,
0.330536}}}, {{{8, 0.}, {-1., 0.}}, {{8, 0.1}, {-0.999176,
0.0405798}}, {{8, 0.2}, {-0.967365, 0.253388}}, {{8,
0.3}, {0.60162, 0.798783}}, {{8, 0.4}, {0.912304, 0.409513}}, {{8,
0.5}, {0.940548, 0.339661}}}};
ListVectorPlot[field, VectorPoints -> All]

Why is that?