Camera defines the transform as:
transform = Matrix.CreateScale(new Vector3(Scale, Scale, 0)) * Matrix.CreateTranslation(new Vector3(-center.X, -_center.Y, 0));
Edit: center is the player location, ie the center of the screen, ideally.
then when I go to draw:
spriteBatch.Begin(SpriteSortMode.FrontToBack, BlendState.AlphaBlend, SamplerState.PointClamp, null, null, null, Camera._transform);
I notice that the warped pixels seem to be the pixels immediately on the tile boundaries
Edit: Further looking indicates that the tiles in the 0 row and column are the ones that are affected,