Reconstructed slice of a carbon sample of 1.530 mm length. The reconstructed plane is parallel to the X-ray beam. (a) The first image, using a 200 × 200 µm beam with Δy = 150 µm and Δω = 5.0°, is highly blurred. (b) The second image, collected using a 150 × 150 µm beam with Δy = 35.0 µm and Δω = 5.0°, is poorly resolved, still showing blurring of the features, but with a resolution more related to the step size Δy; the broken line in (b) shows a saturation streak due to a larger well crystallized grain not eliminated by the threshold procedure. (c) The third image, obtained with a 2 × 2 µm probe and Δy = 8.5 µm and Δω = 3.0°, shows sharper edges with good contrast.