A method for 3D imaging of a sample, in a vessel having a longitudinal axis orthogonal to a horizontal plane, includes capturing, by at least three cameras located at different positions around the vessel, respective 2D images of the sample. Each image comprises pixels having associated pixel values. The optical axis of a first camera is inclined or declined at a first angle relative to the horizontal plane, with the first angle being greater than or equal to zero degrees. The optical axis of a second camera is inclined or declined at a second, larger angle relative to the horizontal plane. The method also includes generating a 3D image of the sample based on the pixel values associated with the 2D image pixels, and one or more look-up tables that collectively indicate, for pixels in each image, expected paths for light traversing the vessel and the sample.